[Serializable] |
using System; using System.Reflection; using System.Globalization; public class MyBinder : Binder { public MyBinder() : base() { } private class BinderState { public object[] args; } public override FieldInfo BindToField( BindingFlags bindingAttr, FieldInfo[] match, object value, CultureInfo culture ) { if(match == null) throw new ArgumentNullException("match"); // Get a field for which 'value' can be converted to that field type. for(int i = 0; i < match.Length; i++) if(ChangeType(value, match[i].FieldType, culture) != null) return match[i]; return null; } public override MethodBase BindToMethod( BindingFlags bindingAttr, MethodBase[] match, ref object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[] names, out object state ) { // Store the arguments to the method in a state object. BinderState myBinderState = new BinderState(); object[] arguments = new Object[args.Length]; args.CopyTo(arguments, 0); myBinderState.args = arguments; state = myBinderState; if(match == null) throw new ArgumentNullException(); // Find a method that has the same parameters as those of 'args'. for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(args.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < args.Length; j++) { // If 'names' is not null then reorder 'args'. if(names != null) { if(names.Length != args.Length) throw new ArgumentException("names and args must have the same number of elements"); for(int k = 0; k < names.Length; k++) if(String.Compare(parameters[j].Name, names[k].ToString()) == 0) args[j] = myBinderState.args[k]; } // Check if the types specified by the user can be converted to parameter type. if(ChangeType(args[j], parameters[j].ParameterType, culture) != null) count += 1; else break; } // Check if the method has been found. if(count == args.Length) return match[i]; } return null; } public override object ChangeType( object value, Type myChangeType, CultureInfo culture ) { // Check if the 'value' can be converted to a value of type 'myType'. if(CanConvertFrom(value.GetType(), myChangeType)) // Return the converted object. return Convert.ChangeType(value, myChangeType); else // Return null. return null; } public override void ReorderArgumentArray( ref object[] args, object state ) { // Return the args that had been reordered by 'BindToMethod'. ((BinderState)state).args.CopyTo(args, 0); } public override MethodBase SelectMethod( BindingFlags bindingAttr, MethodBase[] match, Type[] types, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(types.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < types.Length; j++) // Check if the types specified by the user can be converted to parameter type. if(CanConvertFrom(types[j], parameters[j].ParameterType)) count += 1; else break; // Check if the method has been found. if(count == types.Length) return match[i]; } return null; } public override PropertyInfo SelectProperty( BindingFlags bindingAttr, PropertyInfo[] match, Type returnType, Type[] indexes, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of indexes that match. int count = 0; ParameterInfo[] parameters = match[i].GetIndexParameters(); // Go on to the next property if the number of indexes don't match. if(indexes.Length != parameters.Length) continue; // Match each of the indexes that the user expects the property to have. for(int j = 0; j < indexes.Length; j++) // Check if the types specified by the user can be converted to index type. if(CanConvertFrom(indexes[j], parameters[j].ParameterType)) count += 1; else break; // Check if the property has been found. if(count == indexes.Length) // Check if the return type can be converted to the properties type. if(CanConvertFrom(returnType, match[i].GetType())) return match[i]; else continue; } return null; } // Checks if 'type1' can be converted to 'type2'. (Checks only for primitive types). private bool CanConvertFrom(Type type1, Type type2) { if(type1.IsPrimitive && type2.IsPrimitive) { TypeCode typeCode1 = Type.GetTypeCode(type1); TypeCode typeCode2 = Type.GetTypeCode(type2); // If both 'type1' and 'type2' have same type return true. if(typeCode1 == typeCode2) return true; // Possible conversions from 'Char' follow. if(typeCode1 == TypeCode.Char) switch(typeCode2) { case TypeCode.UInt16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Byte' follow. if(typeCode1 == TypeCode.Byte) switch(typeCode2) { case TypeCode.Char : return true; case TypeCode.UInt16 : return true; case TypeCode.Int16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'SByte' follow. if(typeCode1 == TypeCode.SByte) switch(typeCode2) { case TypeCode.Int16 : return true; case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt16' follow. if(typeCode1 == TypeCode.UInt16) switch(typeCode2) { case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int16' follow. if(typeCode1 == TypeCode.Int16) switch(typeCode2) { case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt32' follow. if(typeCode1 == TypeCode.UInt32) switch(typeCode2) { case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int32' follow. if(typeCode1 == TypeCode.Int32) switch(typeCode2) { case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt64' follow. if(typeCode1 == TypeCode.UInt64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int64' follow. if(typeCode1 == TypeCode.Int64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Single' follow. if(typeCode1 == TypeCode.Single) switch(typeCode2) { case TypeCode.Double : return true; default : return false; } } return false; } } public class MyClass1 { public short myFieldB; public int myFieldA; public void MyMethod(long i, char k) { Console.WriteLine("\nThis is MyMethod(long i, char k)"); } public void MyMethod(long i, long j) { Console.WriteLine("\nThis is MyMethod(long i, long j)"); } } public class Binder_Example { public static void Main() { // Get the type of 'MyClass1'. Type myType = typeof(MyClass1); // Get the instance of 'MyClass1'. MyClass1 myInstance = new MyClass1(); Console.WriteLine("\nDisplaying results of using 'MyBinder' binder\n"); // Get the method information for the method 'MyMethod'. MethodInfo myMethod = myType.GetMethod("MyMethod", BindingFlags.Public | BindingFlags.Instance, new MyBinder(), new Type[] {typeof(short), typeof(short)}, null); Console.WriteLine(myMethod); // Invoke the method named 'MyMethod'. myType.InvokeMember("MyMethod", BindingFlags.InvokeMethod, new MyBinder(), myInstance, new Object[] {(int)32, (int)32}); } }
BindToField | Selects a field from the given set of fields, based on the specified criteria. |
BindToMethod | Selects a method to invoke from the given set of methods, based on the actual arguments. |
CanChangeType | |
ChangeType | Changes the type of the given Object to the given Type. |
Equals (inherited from System.Object) |
See base class member description: System.Object.Equals Derived from System.Object, the primary base class for all objects. |
GetHashCode (inherited from System.Object) |
See base class member description: System.Object.GetHashCode Derived from System.Object, the primary base class for all objects. |
GetType (inherited from System.Object) |
See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects. |
ReorderArgumentArray | Upon returning from Binder.BindToMethod, restores the args argument to what it was when it came from BindToMethod. |
SelectMethod | Selects a method from the given set of methods, based on the argument type. |
SelectProperty | Selects a property from the given set of properties, based on the specified criteria. |
ToString (inherited from System.Object) |
See base class member description: System.Object.ToString Derived from System.Object, the primary base class for all objects. |
ctor #1 | Default constructor. This constructor is called by derived class constructors to initialize state in this type. |
Finalize (inherited from System.Object) |
See base class member description: System.Object.Finalize Derived from System.Object, the primary base class for all objects. |
MemberwiseClone (inherited from System.Object) |
See base class member description: System.Object.MemberwiseClone Derived from System.Object, the primary base class for all objects. |
Hierarchy:
protected Binder(); |
public abstract FieldInfo BindToField( |
bindingAttr
match
value
culture
using System; using System.Reflection; using System.Globalization; public class MyBinder : Binder { public MyBinder() : base() { } private class BinderState { public object[] args; } public override FieldInfo BindToField( BindingFlags bindingAttr, FieldInfo[] match, object value, CultureInfo culture ) { if(match == null) throw new ArgumentNullException("match"); // Get a field for which 'value' can be converted to that field type. for(int i = 0; i < match.Length; i++) if(ChangeType(value, match[i].FieldType, culture) != null) return match[i]; return null; } public override MethodBase BindToMethod( BindingFlags bindingAttr, MethodBase[] match, ref object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[] names, out object state ) { // Store the arguments to the method in a state object. BinderState myBinderState = new BinderState(); object[] arguments = new Object[args.Length]; args.CopyTo(arguments, 0); myBinderState.args = arguments; state = myBinderState; if(match == null) throw new ArgumentNullException(); // Find a method that has the same parameters as those of 'args'. for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(args.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < args.Length; j++) { // If 'names' is not null then reorder 'args'. if(names != null) { if(names.Length != args.Length) throw new ArgumentException("names and args must have the same number of elements"); for(int k = 0; k < names.Length; k++) if(String.Compare(parameters[j].Name, names[k].ToString()) == 0) args[j] = myBinderState.args[k]; } // Check if the types specified by the user can be converted to parameter type. if(ChangeType(args[j], parameters[j].ParameterType, culture) != null) count += 1; else break; } // Check if the method has been found. if(count == args.Length) return match[i]; } return null; } public override object ChangeType( object value, Type myChangeType, CultureInfo culture ) { // Check if the 'value' can be converted to a value of type 'myType'. if(CanConvertFrom(value.GetType(), myChangeType)) // Return the converted object. return Convert.ChangeType(value, myChangeType); else // Return null. return null; } public override void ReorderArgumentArray( ref object[] args, object state ) { // Return the args that had been reordered by 'BindToMethod'. ((BinderState)state).args.CopyTo(args, 0); } public override MethodBase SelectMethod( BindingFlags bindingAttr, MethodBase[] match, Type[] types, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(types.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < types.Length; j++) // Check if the types specified by the user can be converted to parameter type. if(CanConvertFrom(types[j], parameters[j].ParameterType)) count += 1; else break; // Check if the method has been found. if(count == types.Length) return match[i]; } return null; } public override PropertyInfo SelectProperty( BindingFlags bindingAttr, PropertyInfo[] match, Type returnType, Type[] indexes, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of indexes that match. int count = 0; ParameterInfo[] parameters = match[i].GetIndexParameters(); // Go on to the next property if the number of indexes don't match. if(indexes.Length != parameters.Length) continue; // Match each of the indexes that the user expects the property to have. for(int j = 0; j < indexes.Length; j++) // Check if the types specified by the user can be converted to index type. if(CanConvertFrom(indexes[j], parameters[j].ParameterType)) count += 1; else break; // Check if the property has been found. if(count == indexes.Length) // Check if the return type can be converted to the properties type. if(CanConvertFrom(returnType, match[i].GetType())) return match[i]; else continue; } return null; } // Checks if 'type1' can be converted to 'type2'. (Checks only for primitive types). private bool CanConvertFrom(Type type1, Type type2) { if(type1.IsPrimitive && type2.IsPrimitive) { TypeCode typeCode1 = Type.GetTypeCode(type1); TypeCode typeCode2 = Type.GetTypeCode(type2); // If both 'type1' and 'type2' have same type return true. if(typeCode1 == typeCode2) return true; // Possible conversions from 'Char' follow. if(typeCode1 == TypeCode.Char) switch(typeCode2) { case TypeCode.UInt16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Byte' follow. if(typeCode1 == TypeCode.Byte) switch(typeCode2) { case TypeCode.Char : return true; case TypeCode.UInt16 : return true; case TypeCode.Int16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'SByte' follow. if(typeCode1 == TypeCode.SByte) switch(typeCode2) { case TypeCode.Int16 : return true; case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt16' follow. if(typeCode1 == TypeCode.UInt16) switch(typeCode2) { case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int16' follow. if(typeCode1 == TypeCode.Int16) switch(typeCode2) { case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt32' follow. if(typeCode1 == TypeCode.UInt32) switch(typeCode2) { case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int32' follow. if(typeCode1 == TypeCode.Int32) switch(typeCode2) { case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt64' follow. if(typeCode1 == TypeCode.UInt64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int64' follow. if(typeCode1 == TypeCode.Int64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Single' follow. if(typeCode1 == TypeCode.Single) switch(typeCode2) { case TypeCode.Double : return true; default : return false; } } return false; } } public class MyClass1 { public short myFieldB; public int myFieldA; public void MyMethod(long i, char k) { Console.WriteLine("\nThis is MyMethod(long i, char k)"); } public void MyMethod(long i, long j) { Console.WriteLine("\nThis is MyMethod(long i, long j)"); } } public class Binder_Example { public static void Main() { // Get the type of 'MyClass1'. Type myType = typeof(MyClass1); // Get the instance of 'MyClass1'. MyClass1 myInstance = new MyClass1(); Console.WriteLine("\nDisplaying results of using 'MyBinder' binder\n"); // Get the method information for the method 'MyMethod'. MethodInfo myMethod = myType.GetMethod("MyMethod", BindingFlags.Public | BindingFlags.Instance, new MyBinder(), new Type[] {typeof(short), typeof(short)}, null); Console.WriteLine(myMethod); // Invoke the method named 'MyMethod'. myType.InvokeMember("MyMethod", BindingFlags.InvokeMethod, new MyBinder(), myInstance, new Object[] {(int)32, (int)32}); } }
public abstract MethodBase BindToMethod( |
bindingAttr
match
args
modifiers
culture
Not Yet Implemented.
An instance of CultureInfo used to control the coercion of data types. If culture is null, the CultureInfo for the current thread is used.Not Yet Implemented.
names
state
using System; using System.Reflection; using System.Globalization; public class MyBinder : Binder { public MyBinder() : base() { } private class BinderState { public object[] args; } public override FieldInfo BindToField( BindingFlags bindingAttr, FieldInfo[] match, object value, CultureInfo culture ) { if(match == null) throw new ArgumentNullException("match"); // Get a field for which 'value' can be converted to that field type. for(int i = 0; i < match.Length; i++) if(ChangeType(value, match[i].FieldType, culture) != null) return match[i]; return null; } public override MethodBase BindToMethod( BindingFlags bindingAttr, MethodBase[] match, ref object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[] names, out object state ) { // Store the arguments to the method in a state object. BinderState myBinderState = new BinderState(); object[] arguments = new Object[args.Length]; args.CopyTo(arguments, 0); myBinderState.args = arguments; state = myBinderState; if(match == null) throw new ArgumentNullException(); // Find a method that has the same parameters as those of 'args'. for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(args.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < args.Length; j++) { // If 'names' is not null then reorder 'args'. if(names != null) { if(names.Length != args.Length) throw new ArgumentException("names and args must have the same number of elements"); for(int k = 0; k < names.Length; k++) if(String.Compare(parameters[j].Name, names[k].ToString()) == 0) args[j] = myBinderState.args[k]; } // Check if the types specified by the user can be converted to parameter type. if(ChangeType(args[j], parameters[j].ParameterType, culture) != null) count += 1; else break; } // Check if the method has been found. if(count == args.Length) return match[i]; } return null; } public override object ChangeType( object value, Type myChangeType, CultureInfo culture ) { // Check if the 'value' can be converted to a value of type 'myType'. if(CanConvertFrom(value.GetType(), myChangeType)) // Return the converted object. return Convert.ChangeType(value, myChangeType); else // Return null. return null; } public override void ReorderArgumentArray( ref object[] args, object state ) { // Return the args that had been reordered by 'BindToMethod'. ((BinderState)state).args.CopyTo(args, 0); } public override MethodBase SelectMethod( BindingFlags bindingAttr, MethodBase[] match, Type[] types, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(types.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < types.Length; j++) // Check if the types specified by the user can be converted to parameter type. if(CanConvertFrom(types[j], parameters[j].ParameterType)) count += 1; else break; // Check if the method has been found. if(count == types.Length) return match[i]; } return null; } public override PropertyInfo SelectProperty( BindingFlags bindingAttr, PropertyInfo[] match, Type returnType, Type[] indexes, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of indexes that match. int count = 0; ParameterInfo[] parameters = match[i].GetIndexParameters(); // Go on to the next property if the number of indexes don't match. if(indexes.Length != parameters.Length) continue; // Match each of the indexes that the user expects the property to have. for(int j = 0; j < indexes.Length; j++) // Check if the types specified by the user can be converted to index type. if(CanConvertFrom(indexes[j], parameters[j].ParameterType)) count += 1; else break; // Check if the property has been found. if(count == indexes.Length) // Check if the return type can be converted to the properties type. if(CanConvertFrom(returnType, match[i].GetType())) return match[i]; else continue; } return null; } // Checks if 'type1' can be converted to 'type2'. (Checks only for primitive types). private bool CanConvertFrom(Type type1, Type type2) { if(type1.IsPrimitive && type2.IsPrimitive) { TypeCode typeCode1 = Type.GetTypeCode(type1); TypeCode typeCode2 = Type.GetTypeCode(type2); // If both 'type1' and 'type2' have same type return true. if(typeCode1 == typeCode2) return true; // Possible conversions from 'Char' follow. if(typeCode1 == TypeCode.Char) switch(typeCode2) { case TypeCode.UInt16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Byte' follow. if(typeCode1 == TypeCode.Byte) switch(typeCode2) { case TypeCode.Char : return true; case TypeCode.UInt16 : return true; case TypeCode.Int16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'SByte' follow. if(typeCode1 == TypeCode.SByte) switch(typeCode2) { case TypeCode.Int16 : return true; case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt16' follow. if(typeCode1 == TypeCode.UInt16) switch(typeCode2) { case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int16' follow. if(typeCode1 == TypeCode.Int16) switch(typeCode2) { case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt32' follow. if(typeCode1 == TypeCode.UInt32) switch(typeCode2) { case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int32' follow. if(typeCode1 == TypeCode.Int32) switch(typeCode2) { case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt64' follow. if(typeCode1 == TypeCode.UInt64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int64' follow. if(typeCode1 == TypeCode.Int64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Single' follow. if(typeCode1 == TypeCode.Single) switch(typeCode2) { case TypeCode.Double : return true; default : return false; } } return false; } } public class MyClass1 { public short myFieldB; public int myFieldA; public void MyMethod(long i, char k) { Console.WriteLine("\nThis is MyMethod(long i, char k)"); } public void MyMethod(long i, long j) { Console.WriteLine("\nThis is MyMethod(long i, long j)"); } } public class Binder_Example { public static void Main() { // Get the type of 'MyClass1'. Type myType = typeof(MyClass1); // Get the instance of 'MyClass1'. MyClass1 myInstance = new MyClass1(); Console.WriteLine("\nDisplaying results of using 'MyBinder' binder\n"); // Get the method information for the method 'MyMethod'. MethodInfo myMethod = myType.GetMethod("MyMethod", BindingFlags.Public | BindingFlags.Instance, new MyBinder(), new Type[] {typeof(short), typeof(short)}, null); Console.WriteLine(myMethod); // Invoke the method named 'MyMethod'. myType.InvokeMember("MyMethod", BindingFlags.InvokeMethod, new MyBinder(), myInstance, new Object[] {(int)32, (int)32}); } }
public virtual bool CanChangeType( |
value
type
culture
public abstract object ChangeType( |
value
type
culture
The general principle is that ChangeType should perform only widening coercions, which never lose data. An example of a widening coercion is coercing a value that is a 32-bit signed integer to a value that is a 64-bit signed integer. This is distinguished from a narrowing coercion, which may lose data. An example of a narrowing coercion is coercing a 64-bit signed integer to a 32-bit signed integer.
The following table lists the coercions performed by the default ChangeType.
Source Type | Target Type |
---|---|
Any type | Its base type. |
Any type | The interface it implements. |
Char | UInt16, UInt32, Int32, UInt64, Int64, Single, Double |
Byte | Char, UInt16, Int16, UInt32, Int32, UInt64, Int64, Single, Double |
SByte | Int16, Int32, Int64, Single, Double |
UInt16 | UInt32, Int32, UInt64, Int64, Single, Double |
Int16 | Int32, Int64, Single, Double |
UInt32 | UInt64, Int64, Single, Double |
Int32 | Int64, Single, Double |
UInt64 | Single, Double |
Int64 | Single, Double |
Single | Double |
Non-reference | By-reference. |
using System; using System.Reflection; using System.Globalization; public class MyBinder : Binder { public MyBinder() : base() { } private class BinderState { public object[] args; } public override FieldInfo BindToField( BindingFlags bindingAttr, FieldInfo[] match, object value, CultureInfo culture ) { if(match == null) throw new ArgumentNullException("match"); // Get a field for which 'value' can be converted to that field type. for(int i = 0; i < match.Length; i++) if(ChangeType(value, match[i].FieldType, culture) != null) return match[i]; return null; } public override MethodBase BindToMethod( BindingFlags bindingAttr, MethodBase[] match, ref object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[] names, out object state ) { // Store the arguments to the method in a state object. BinderState myBinderState = new BinderState(); object[] arguments = new Object[args.Length]; args.CopyTo(arguments, 0); myBinderState.args = arguments; state = myBinderState; if(match == null) throw new ArgumentNullException(); // Find a method that has the same parameters as those of 'args'. for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(args.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < args.Length; j++) { // If 'names' is not null then reorder 'args'. if(names != null) { if(names.Length != args.Length) throw new ArgumentException("names and args must have the same number of elements"); for(int k = 0; k < names.Length; k++) if(String.Compare(parameters[j].Name, names[k].ToString()) == 0) args[j] = myBinderState.args[k]; } // Check if the types specified by the user can be converted to parameter type. if(ChangeType(args[j], parameters[j].ParameterType, culture) != null) count += 1; else break; } // Check if the method has been found. if(count == args.Length) return match[i]; } return null; } public override object ChangeType( object value, Type myChangeType, CultureInfo culture ) { // Check if the 'value' can be converted to a value of type 'myType'. if(CanConvertFrom(value.GetType(), myChangeType)) // Return the converted object. return Convert.ChangeType(value, myChangeType); else // Return null. return null; } public override void ReorderArgumentArray( ref object[] args, object state ) { // Return the args that had been reordered by 'BindToMethod'. ((BinderState)state).args.CopyTo(args, 0); } public override MethodBase SelectMethod( BindingFlags bindingAttr, MethodBase[] match, Type[] types, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(types.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < types.Length; j++) // Check if the types specified by the user can be converted to parameter type. if(CanConvertFrom(types[j], parameters[j].ParameterType)) count += 1; else break; // Check if the method has been found. if(count == types.Length) return match[i]; } return null; } public override PropertyInfo SelectProperty( BindingFlags bindingAttr, PropertyInfo[] match, Type returnType, Type[] indexes, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of indexes that match. int count = 0; ParameterInfo[] parameters = match[i].GetIndexParameters(); // Go on to the next property if the number of indexes don't match. if(indexes.Length != parameters.Length) continue; // Match each of the indexes that the user expects the property to have. for(int j = 0; j < indexes.Length; j++) // Check if the types specified by the user can be converted to index type. if(CanConvertFrom(indexes[j], parameters[j].ParameterType)) count += 1; else break; // Check if the property has been found. if(count == indexes.Length) // Check if the return type can be converted to the properties type. if(CanConvertFrom(returnType, match[i].GetType())) return match[i]; else continue; } return null; } // Checks if 'type1' can be converted to 'type2'. (Checks only for primitive types). private bool CanConvertFrom(Type type1, Type type2) { if(type1.IsPrimitive && type2.IsPrimitive) { TypeCode typeCode1 = Type.GetTypeCode(type1); TypeCode typeCode2 = Type.GetTypeCode(type2); // If both 'type1' and 'type2' have same type return true. if(typeCode1 == typeCode2) return true; // Possible conversions from 'Char' follow. if(typeCode1 == TypeCode.Char) switch(typeCode2) { case TypeCode.UInt16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Byte' follow. if(typeCode1 == TypeCode.Byte) switch(typeCode2) { case TypeCode.Char : return true; case TypeCode.UInt16 : return true; case TypeCode.Int16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'SByte' follow. if(typeCode1 == TypeCode.SByte) switch(typeCode2) { case TypeCode.Int16 : return true; case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt16' follow. if(typeCode1 == TypeCode.UInt16) switch(typeCode2) { case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int16' follow. if(typeCode1 == TypeCode.Int16) switch(typeCode2) { case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt32' follow. if(typeCode1 == TypeCode.UInt32) switch(typeCode2) { case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int32' follow. if(typeCode1 == TypeCode.Int32) switch(typeCode2) { case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt64' follow. if(typeCode1 == TypeCode.UInt64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int64' follow. if(typeCode1 == TypeCode.Int64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Single' follow. if(typeCode1 == TypeCode.Single) switch(typeCode2) { case TypeCode.Double : return true; default : return false; } } return false; } } public class MyClass1 { public short myFieldB; public int myFieldA; public void MyMethod(long i, char k) { Console.WriteLine("\nThis is MyMethod(long i, char k)"); } public void MyMethod(long i, long j) { Console.WriteLine("\nThis is MyMethod(long i, long j)"); } } public class Binder_Example { public static void Main() { // Get the type of 'MyClass1'. Type myType = typeof(MyClass1); // Get the instance of 'MyClass1'. MyClass1 myInstance = new MyClass1(); Console.WriteLine("\nDisplaying results of using 'MyBinder' binder\n"); // Get the method information for the method 'MyMethod'. MethodInfo myMethod = myType.GetMethod("MyMethod", BindingFlags.Public | BindingFlags.Instance, new MyBinder(), new Type[] {typeof(short), typeof(short)}, null); Console.WriteLine(myMethod); // Invoke the method named 'MyMethod'. myType.InvokeMember("MyMethod", BindingFlags.InvokeMethod, new MyBinder(), myInstance, new Object[] {(int)32, (int)32}); } }
~Binder(); |
public virtual int GetHashCode(); |
public Type GetType(); |
protected object MemberwiseClone(); |
args
state
using System; using System.Reflection; using System.Globalization; public class MyBinder : Binder { public MyBinder() : base() { } private class BinderState { public object[] args; } public override FieldInfo BindToField( BindingFlags bindingAttr, FieldInfo[] match, object value, CultureInfo culture ) { if(match == null) throw new ArgumentNullException("match"); // Get a field for which 'value' can be converted to that field type. for(int i = 0; i < match.Length; i++) if(ChangeType(value, match[i].FieldType, culture) != null) return match[i]; return null; } public override MethodBase BindToMethod( BindingFlags bindingAttr, MethodBase[] match, ref object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[] names, out object state ) { // Store the arguments to the method in a state object. BinderState myBinderState = new BinderState(); object[] arguments = new Object[args.Length]; args.CopyTo(arguments, 0); myBinderState.args = arguments; state = myBinderState; if(match == null) throw new ArgumentNullException(); // Find a method that has the same parameters as those of 'args'. for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(args.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < args.Length; j++) { // If 'names' is not null then reorder 'args'. if(names != null) { if(names.Length != args.Length) throw new ArgumentException("names and args must have the same number of elements"); for(int k = 0; k < names.Length; k++) if(String.Compare(parameters[j].Name, names[k].ToString()) == 0) args[j] = myBinderState.args[k]; } // Check if the types specified by the user can be converted to parameter type. if(ChangeType(args[j], parameters[j].ParameterType, culture) != null) count += 1; else break; } // Check if the method has been found. if(count == args.Length) return match[i]; } return null; } public override object ChangeType( object value, Type myChangeType, CultureInfo culture ) { // Check if the 'value' can be converted to a value of type 'myType'. if(CanConvertFrom(value.GetType(), myChangeType)) // Return the converted object. return Convert.ChangeType(value, myChangeType); else // Return null. return null; } public override void ReorderArgumentArray( ref object[] args, object state ) { // Return the args that had been reordered by 'BindToMethod'. ((BinderState)state).args.CopyTo(args, 0); } public override MethodBase SelectMethod( BindingFlags bindingAttr, MethodBase[] match, Type[] types, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(types.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < types.Length; j++) // Check if the types specified by the user can be converted to parameter type. if(CanConvertFrom(types[j], parameters[j].ParameterType)) count += 1; else break; // Check if the method has been found. if(count == types.Length) return match[i]; } return null; } public override PropertyInfo SelectProperty( BindingFlags bindingAttr, PropertyInfo[] match, Type returnType, Type[] indexes, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of indexes that match. int count = 0; ParameterInfo[] parameters = match[i].GetIndexParameters(); // Go on to the next property if the number of indexes don't match. if(indexes.Length != parameters.Length) continue; // Match each of the indexes that the user expects the property to have. for(int j = 0; j < indexes.Length; j++) // Check if the types specified by the user can be converted to index type. if(CanConvertFrom(indexes[j], parameters[j].ParameterType)) count += 1; else break; // Check if the property has been found. if(count == indexes.Length) // Check if the return type can be converted to the properties type. if(CanConvertFrom(returnType, match[i].GetType())) return match[i]; else continue; } return null; } // Checks if 'type1' can be converted to 'type2'. (Checks only for primitive types). private bool CanConvertFrom(Type type1, Type type2) { if(type1.IsPrimitive && type2.IsPrimitive) { TypeCode typeCode1 = Type.GetTypeCode(type1); TypeCode typeCode2 = Type.GetTypeCode(type2); // If both 'type1' and 'type2' have same type return true. if(typeCode1 == typeCode2) return true; // Possible conversions from 'Char' follow. if(typeCode1 == TypeCode.Char) switch(typeCode2) { case TypeCode.UInt16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Byte' follow. if(typeCode1 == TypeCode.Byte) switch(typeCode2) { case TypeCode.Char : return true; case TypeCode.UInt16 : return true; case TypeCode.Int16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'SByte' follow. if(typeCode1 == TypeCode.SByte) switch(typeCode2) { case TypeCode.Int16 : return true; case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt16' follow. if(typeCode1 == TypeCode.UInt16) switch(typeCode2) { case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int16' follow. if(typeCode1 == TypeCode.Int16) switch(typeCode2) { case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt32' follow. if(typeCode1 == TypeCode.UInt32) switch(typeCode2) { case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int32' follow. if(typeCode1 == TypeCode.Int32) switch(typeCode2) { case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt64' follow. if(typeCode1 == TypeCode.UInt64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int64' follow. if(typeCode1 == TypeCode.Int64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Single' follow. if(typeCode1 == TypeCode.Single) switch(typeCode2) { case TypeCode.Double : return true; default : return false; } } return false; } } public class MyClass1 { public short myFieldB; public int myFieldA; public void MyMethod(long i, char k) { Console.WriteLine("\nThis is MyMethod(long i, char k)"); } public void MyMethod(long i, long j) { Console.WriteLine("\nThis is MyMethod(long i, long j)"); } } public class Binder_Example { public static void Main() { // Get the type of 'MyClass1'. Type myType = typeof(MyClass1); // Get the instance of 'MyClass1'. MyClass1 myInstance = new MyClass1(); Console.WriteLine("\nDisplaying results of using 'MyBinder' binder\n"); // Get the method information for the method 'MyMethod'. MethodInfo myMethod = myType.GetMethod("MyMethod", BindingFlags.Public | BindingFlags.Instance, new MyBinder(), new Type[] {typeof(short), typeof(short)}, null); Console.WriteLine(myMethod); // Invoke the method named 'MyMethod'. myType.InvokeMember("MyMethod", BindingFlags.InvokeMethod, new MyBinder(), myInstance, new Object[] {(int)32, (int)32}); } }
public abstract MethodBase SelectMethod( |
bindingAttr
match
types
modifiers
using System; using System.Reflection; using System.Globalization; public class MyBinder : Binder { public MyBinder() : base() { } private class BinderState { public object[] args; } public override FieldInfo BindToField( BindingFlags bindingAttr, FieldInfo[] match, object value, CultureInfo culture ) { if(match == null) throw new ArgumentNullException("match"); // Get a field for which 'value' can be converted to that field type. for(int i = 0; i < match.Length; i++) if(ChangeType(value, match[i].FieldType, culture) != null) return match[i]; return null; } public override MethodBase BindToMethod( BindingFlags bindingAttr, MethodBase[] match, ref object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[] names, out object state ) { // Store the arguments to the method in a state object. BinderState myBinderState = new BinderState(); object[] arguments = new Object[args.Length]; args.CopyTo(arguments, 0); myBinderState.args = arguments; state = myBinderState; if(match == null) throw new ArgumentNullException(); // Find a method that has the same parameters as those of 'args'. for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(args.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < args.Length; j++) { // If 'names' is not null then reorder 'args'. if(names != null) { if(names.Length != args.Length) throw new ArgumentException("names and args must have the same number of elements"); for(int k = 0; k < names.Length; k++) if(String.Compare(parameters[j].Name, names[k].ToString()) == 0) args[j] = myBinderState.args[k]; } // Check if the types specified by the user can be converted to parameter type. if(ChangeType(args[j], parameters[j].ParameterType, culture) != null) count += 1; else break; } // Check if the method has been found. if(count == args.Length) return match[i]; } return null; } public override object ChangeType( object value, Type myChangeType, CultureInfo culture ) { // Check if the 'value' can be converted to a value of type 'myType'. if(CanConvertFrom(value.GetType(), myChangeType)) // Return the converted object. return Convert.ChangeType(value, myChangeType); else // Return null. return null; } public override void ReorderArgumentArray( ref object[] args, object state ) { // Return the args that had been reordered by 'BindToMethod'. ((BinderState)state).args.CopyTo(args, 0); } public override MethodBase SelectMethod( BindingFlags bindingAttr, MethodBase[] match, Type[] types, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(types.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < types.Length; j++) // Check if the types specified by the user can be converted to parameter type. if(CanConvertFrom(types[j], parameters[j].ParameterType)) count += 1; else break; // Check if the method has been found. if(count == types.Length) return match[i]; } return null; } public override PropertyInfo SelectProperty( BindingFlags bindingAttr, PropertyInfo[] match, Type returnType, Type[] indexes, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of indexes that match. int count = 0; ParameterInfo[] parameters = match[i].GetIndexParameters(); // Go on to the next property if the number of indexes don't match. if(indexes.Length != parameters.Length) continue; // Match each of the indexes that the user expects the property to have. for(int j = 0; j < indexes.Length; j++) // Check if the types specified by the user can be converted to index type. if(CanConvertFrom(indexes[j], parameters[j].ParameterType)) count += 1; else break; // Check if the property has been found. if(count == indexes.Length) // Check if the return type can be converted to the properties type. if(CanConvertFrom(returnType, match[i].GetType())) return match[i]; else continue; } return null; } // Checks if 'type1' can be converted to 'type2'. (Checks only for primitive types). private bool CanConvertFrom(Type type1, Type type2) { if(type1.IsPrimitive && type2.IsPrimitive) { TypeCode typeCode1 = Type.GetTypeCode(type1); TypeCode typeCode2 = Type.GetTypeCode(type2); // If both 'type1' and 'type2' have same type return true. if(typeCode1 == typeCode2) return true; // Possible conversions from 'Char' follow. if(typeCode1 == TypeCode.Char) switch(typeCode2) { case TypeCode.UInt16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Byte' follow. if(typeCode1 == TypeCode.Byte) switch(typeCode2) { case TypeCode.Char : return true; case TypeCode.UInt16 : return true; case TypeCode.Int16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'SByte' follow. if(typeCode1 == TypeCode.SByte) switch(typeCode2) { case TypeCode.Int16 : return true; case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt16' follow. if(typeCode1 == TypeCode.UInt16) switch(typeCode2) { case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int16' follow. if(typeCode1 == TypeCode.Int16) switch(typeCode2) { case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt32' follow. if(typeCode1 == TypeCode.UInt32) switch(typeCode2) { case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int32' follow. if(typeCode1 == TypeCode.Int32) switch(typeCode2) { case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt64' follow. if(typeCode1 == TypeCode.UInt64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int64' follow. if(typeCode1 == TypeCode.Int64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Single' follow. if(typeCode1 == TypeCode.Single) switch(typeCode2) { case TypeCode.Double : return true; default : return false; } } return false; } } public class MyClass1 { public short myFieldB; public int myFieldA; public void MyMethod(long i, char k) { Console.WriteLine("\nThis is MyMethod(long i, char k)"); } public void MyMethod(long i, long j) { Console.WriteLine("\nThis is MyMethod(long i, long j)"); } } public class Binder_Example { public static void Main() { // Get the type of 'MyClass1'. Type myType = typeof(MyClass1); // Get the instance of 'MyClass1'. MyClass1 myInstance = new MyClass1(); Console.WriteLine("\nDisplaying results of using 'MyBinder' binder\n"); // Get the method information for the method 'MyMethod'. MethodInfo myMethod = myType.GetMethod("MyMethod", BindingFlags.Public | BindingFlags.Instance, new MyBinder(), new Type[] {typeof(short), typeof(short)}, null); Console.WriteLine(myMethod); // Invoke the method named 'MyMethod'. myType.InvokeMember("MyMethod", BindingFlags.InvokeMethod, new MyBinder(), myInstance, new Object[] {(int)32, (int)32}); } }
public abstract PropertyInfo SelectProperty( |
bindingAttr
match
returnType
indexes
modifiers
using System; using System.Reflection; using System.Globalization; public class MyBinder : Binder { public MyBinder() : base() { } private class BinderState { public object[] args; } public override FieldInfo BindToField( BindingFlags bindingAttr, FieldInfo[] match, object value, CultureInfo culture ) { if(match == null) throw new ArgumentNullException("match"); // Get a field for which 'value' can be converted to that field type. for(int i = 0; i < match.Length; i++) if(ChangeType(value, match[i].FieldType, culture) != null) return match[i]; return null; } public override MethodBase BindToMethod( BindingFlags bindingAttr, MethodBase[] match, ref object[] args, ParameterModifier[] modifiers, CultureInfo culture, string[] names, out object state ) { // Store the arguments to the method in a state object. BinderState myBinderState = new BinderState(); object[] arguments = new Object[args.Length]; args.CopyTo(arguments, 0); myBinderState.args = arguments; state = myBinderState; if(match == null) throw new ArgumentNullException(); // Find a method that has the same parameters as those of 'args'. for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(args.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < args.Length; j++) { // If 'names' is not null then reorder 'args'. if(names != null) { if(names.Length != args.Length) throw new ArgumentException("names and args must have the same number of elements"); for(int k = 0; k < names.Length; k++) if(String.Compare(parameters[j].Name, names[k].ToString()) == 0) args[j] = myBinderState.args[k]; } // Check if the types specified by the user can be converted to parameter type. if(ChangeType(args[j], parameters[j].ParameterType, culture) != null) count += 1; else break; } // Check if the method has been found. if(count == args.Length) return match[i]; } return null; } public override object ChangeType( object value, Type myChangeType, CultureInfo culture ) { // Check if the 'value' can be converted to a value of type 'myType'. if(CanConvertFrom(value.GetType(), myChangeType)) // Return the converted object. return Convert.ChangeType(value, myChangeType); else // Return null. return null; } public override void ReorderArgumentArray( ref object[] args, object state ) { // Return the args that had been reordered by 'BindToMethod'. ((BinderState)state).args.CopyTo(args, 0); } public override MethodBase SelectMethod( BindingFlags bindingAttr, MethodBase[] match, Type[] types, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of parameters that match. int count = 0; ParameterInfo[] parameters = match[i].GetParameters(); // Go on to the next method if the number of parameters don't match. if(types.Length != parameters.Length) continue; // Match each of the parameters that the user expects the method to have. for(int j = 0; j < types.Length; j++) // Check if the types specified by the user can be converted to parameter type. if(CanConvertFrom(types[j], parameters[j].ParameterType)) count += 1; else break; // Check if the method has been found. if(count == types.Length) return match[i]; } return null; } public override PropertyInfo SelectProperty( BindingFlags bindingAttr, PropertyInfo[] match, Type returnType, Type[] indexes, ParameterModifier[] modifiers ) { if(match == null) throw new ArgumentNullException("match"); for(int i = 0; i < match.Length; i++) { // Count the number of indexes that match. int count = 0; ParameterInfo[] parameters = match[i].GetIndexParameters(); // Go on to the next property if the number of indexes don't match. if(indexes.Length != parameters.Length) continue; // Match each of the indexes that the user expects the property to have. for(int j = 0; j < indexes.Length; j++) // Check if the types specified by the user can be converted to index type. if(CanConvertFrom(indexes[j], parameters[j].ParameterType)) count += 1; else break; // Check if the property has been found. if(count == indexes.Length) // Check if the return type can be converted to the properties type. if(CanConvertFrom(returnType, match[i].GetType())) return match[i]; else continue; } return null; } // Checks if 'type1' can be converted to 'type2'. (Checks only for primitive types). private bool CanConvertFrom(Type type1, Type type2) { if(type1.IsPrimitive && type2.IsPrimitive) { TypeCode typeCode1 = Type.GetTypeCode(type1); TypeCode typeCode2 = Type.GetTypeCode(type2); // If both 'type1' and 'type2' have same type return true. if(typeCode1 == typeCode2) return true; // Possible conversions from 'Char' follow. if(typeCode1 == TypeCode.Char) switch(typeCode2) { case TypeCode.UInt16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Byte' follow. if(typeCode1 == TypeCode.Byte) switch(typeCode2) { case TypeCode.Char : return true; case TypeCode.UInt16 : return true; case TypeCode.Int16 : return true; case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'SByte' follow. if(typeCode1 == TypeCode.SByte) switch(typeCode2) { case TypeCode.Int16 : return true; case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt16' follow. if(typeCode1 == TypeCode.UInt16) switch(typeCode2) { case TypeCode.UInt32 : return true; case TypeCode.Int32 : return true; case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int16' follow. if(typeCode1 == TypeCode.Int16) switch(typeCode2) { case TypeCode.Int32 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt32' follow. if(typeCode1 == TypeCode.UInt32) switch(typeCode2) { case TypeCode.UInt64 : return true; case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int32' follow. if(typeCode1 == TypeCode.Int32) switch(typeCode2) { case TypeCode.Int64 : return true; case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'UInt64' follow. if(typeCode1 == TypeCode.UInt64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Int64' follow. if(typeCode1 == TypeCode.Int64) switch(typeCode2) { case TypeCode.Single : return true; case TypeCode.Double : return true; default : return false; } // Possible conversions from 'Single' follow. if(typeCode1 == TypeCode.Single) switch(typeCode2) { case TypeCode.Double : return true; default : return false; } } return false; } } public class MyClass1 { public short myFieldB; public int myFieldA; public void MyMethod(long i, char k) { Console.WriteLine("\nThis is MyMethod(long i, char k)"); } public void MyMethod(long i, long j) { Console.WriteLine("\nThis is MyMethod(long i, long j)"); } } public class Binder_Example { public static void Main() { // Get the type of 'MyClass1'. Type myType = typeof(MyClass1); // Get the instance of 'MyClass1'. MyClass1 myInstance = new MyClass1(); Console.WriteLine("\nDisplaying results of using 'MyBinder' binder\n"); // Get the method information for the method 'MyMethod'. MethodInfo myMethod = myType.GetMethod("MyMethod", BindingFlags.Public | BindingFlags.Instance, new MyBinder(), new Type[] {typeof(short), typeof(short)}, null); Console.WriteLine(myMethod); // Invoke the method named 'MyMethod'. myType.InvokeMember("MyMethod", BindingFlags.InvokeMethod, new MyBinder(), myInstance, new Object[] {(int)32, (int)32}); } }
public virtual string ToString(); |