System.IO.FileNotFoundException Class

Summary

The exception that is thrown when an attempt to access a file that does not exist on disk fails.

C# Syntax:

[Serializable] public class FileNotFoundException : IOException

FileNotFoundException uses the HRESULT COR_E_FILENOTFOUND which has the value 0x80070002.

System.IO Namespace | Exception | MSDN: handlingthrowingexceptions

System.IO.FileNotFoundException Member List:

Public Constructors

ctor #1	Overloaded: .ctor() Default constructor. This constructor is called by derived class constructors to initialize state in this type. Initializes a new instance of the FileNotFoundException class with its message string set to the empty string ("") and its HRESULT set to COR_E_FILENOTFOUND.
ctor #2	Overloaded: .ctor(string message) Initializes a new instance of the FileNotFoundException class with its message string set to message and its HRESULT set to COR_E_FILENOTFOUND.
ctor #4	Overloaded: .ctor(string message, Exception innerException) Initializes a new instance of the FileNotFoundException class with a specified error message and a reference to the inner exception that is the cause of this exception.
ctor #5	Overloaded: .ctor(string message, string fileName) Initializes a new instance of the FileNotFoundException class with its message string set to message, specifying the file name that cannot be found, and its HRESULT set to COR_E_FILENOTFOUND.
ctor #6	Overloaded: .ctor(string message, string fileName, Exception innerException) Initializes a new instance of the FileNotFoundException class with a specified error message and a reference to the inner exception that is the cause of this exception.

Public Properties

FileName	Read-only Gets the name of the file that cannot be found.
FusionLog	Read-only Gets the log file that describes why loading of an assembly failed.
HelpLink (inherited from System.Exception)	Read-write See base class member description: System.Exception.HelpLink Gets or sets a link to the help file associated with this exception.
InnerException (inherited from System.Exception)	Read-only See base class member description: System.Exception.InnerException Gets the Exception instance that caused the current exception.
Message	Read-only Overridden: Gets the error message that explains the reason for the exception.
Source (inherited from System.Exception)	Read-write See base class member description: System.Exception.Source Gets or sets the name of the application or the object that causes the error.
StackTrace (inherited from System.Exception)	Read-only See base class member description: System.Exception.StackTrace Gets a string representation of the frames on the call stack at the time the current exception was thrown.
TargetSite (inherited from System.Exception)	Read-only See base class member description: System.Exception.TargetSite Gets the method that throws the current exception.

Public Methods

Equals (inherited from System.Object)	See base class member description: System.Object.Equals Derived from System.Object, the primary base class for all objects.
GetBaseException (inherited from System.Exception)	See base class member description: System.Exception.GetBaseException When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.
GetHashCode (inherited from System.Object)	See base class member description: System.Object.GetHashCode Derived from System.Object, the primary base class for all objects.
GetObjectData	Overridden: Sets the SerializationInfo object with the file name and additional exception information.
GetType (inherited from System.Object)	See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects.
ToString	Overridden: Returns the fully qualified name of this exception and possibly the error message, the name of the inner exception, and the stack trace.

Protected Constructors

ctor #3

Overloaded: .ctor(SerializationInfo info, StreamingContext context) Initializes a new instance of the FileNotFoundException class with the specified serialization and context information.

Protected Properties

HResult (inherited from System.Exception)

Read-write See base class member description: System.Exception.HResult Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.

Protected Methods

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:

• System.Object
• System.Exception
• System.SystemException
• System.IO.IOException
• System.IO.FileNotFoundException

System.IO.FileNotFoundException Member Details

Summary

Initializes a new instance of the FileNotFoundException class with its message string set to the empty string ("") and its HRESULT set to COR_E_FILENOTFOUND.

Default constructor. This constructor is called by derived class constructors to initialize state in this type.

C# Syntax:

public FileNotFoundException();

This constructor initializes the FileNotFoundException.Message property of the new instance to a system-supplied message that describes the error, such as "Could not find the specified file." This message takes into account the current system culture.

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Summary

Initializes a new instance of the FileNotFoundException class with its message string set to message and its HRESULT set to COR_E_FILENOTFOUND.

C# Syntax:

public FileNotFoundException(    string message );

message

A String that describes the error. The content of message is intended to be understood by humans. The caller of this constructor is required to ensure that this string has been localized for the current system culture.

This constructor initializes the FileNotFoundException.Message property of the new instance using message.

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Summary

Initializes a new instance of the FileNotFoundException class with the specified serialization and context information.

C# Syntax:

protected FileNotFoundException(    SerializationInfo info,    StreamingContext context );

info

The data for serializing or deserializing the file.

context

The source and destination for the file.

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Summary

Initializes a new instance of the FileNotFoundException class with a specified error message and a reference to the inner exception that is the cause of this exception.

C# Syntax:

public FileNotFoundException(    string message,    Exception innerException );

message

A String that describes the error. The content of message is intended to be understood by humans. The caller of this constructor is required to ensure that this string has been localized for the current system culture.

innerException

The exception that is the cause of the current exception. If the innerException parameter is not null, the current exception is raised in a catch block that handles the inner exception.

An exception that is thrown as a direct result of a previous exception should include a reference to the previous exception in the Exception.InnerException property. The Exception.InnerException property returns the same value that is passed into the constructor, or null if the Exception.InnerException property does not supply the inner exception value to the constructor.

The following table shows the initial property values for an instance of FileNotFoundException.

Property	Value
Exception.InnerException	The inner exception reference.
Exception.Message	The error message string.

For more information on inner exceptions, see Exception.InnerException.

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Summary

Initializes a new instance of the FileNotFoundException class with its message string set to message, specifying the file name that cannot be found, and its HRESULT set to COR_E_FILENOTFOUND.

C# Syntax:

public FileNotFoundException(    string message,    string fileName );

message

A String that describes the error. The content of message is intended to be understood by humans. The caller of this constructor is required to ensure that this string has been localized for the current system culture.

fileName

A String containing the full name of the file with the invalid image.

The constructor initializes the FileNotFoundException.Message property of the new instance using message and the FileNotFoundException.FileName property using fileName.

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Summary

Initializes a new instance of the FileNotFoundException class with a specified error message and a reference to the inner exception that is the cause of this exception.

C# Syntax:

public FileNotFoundException(    string message,    string fileName,    Exception innerException );

message

The error message that explains the reason for the exception.

fileName

A String containing the full name of the file with the invalid image.

innerException

The exception that is the cause of the current exception. If the innerException parameter is not null, the current exception is raised in a catch block that handles the inner exception.

An exception that is thrown as a direct result of a previous exception should include a reference to the previous exception in the Exception.InnerException property. The Exception.InnerException property returns the same value that is passed into the constructor, or null if the Exception.InnerException property does not supply the inner exception value to the constructor.

The following table shows the initial property values for an instance of FileNotFoundException.

Property	Value
Exception.InnerException	The inner exception reference.
Exception.Message	The error message string.

For more information on inner exceptions, see Exception.InnerException.

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Summary

Gets the name of the file that cannot be found.

C# Syntax:

public string FileName {get;}

This property is read-only.

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Summary

Gets the log file that describes why loading of an assembly failed.

C# Syntax:

public string FusionLog {get;}

Exceptions

Exception Type	Condition
SecurityException	The caller does not have the required permission.

SecurityPermission to provide evidence and view and modify policy. Associated enumerations: SecurityPermissionFlag.ControlEvidence, SecurityPermissionFlag.ControlPolicy.

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Inherited
See base class member description: System.Exception.HelpLink

Summary

Gets or sets a link to the help file associated with this exception.

C# Syntax:

public virtual string HelpLink {get; set;}

The return value, which represents a help file, is a URN or URL. For example, the HelpLink value could be:

"file:///C:/Applications/Bazzal/help.html#ErrorNum42"

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Inherited
See base class member description: System.Exception.HResult

Summary

Gets or sets HRESULT, a coded numerical value that is assigned to a specific exception.

C# Syntax:

protected int HResult {get; set;}

HRESULT is a 32-bit value, divided into three different fields: a severity code, a facility code, and an error code. The severity code indicates whether the return value represents information, warning, or error. The facility code identifies the area of the system responsible for the error. The error code is a unique number that is assigned to represent the exception. Each exception is mapped to a distinct HRESULT. When managed code throws an exception, the runtime passes the HRESULT to the COM client. When unmanaged code returns an error, the HRESULT is converted to an exception, which is then thrown by the runtime.

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Inherited
See base class member description: System.Exception.InnerException

Summary

Gets the Exception instance that caused the current exception.

C# Syntax:

public Exception InnerException {get;}

When an exception X is thrown as a direct result of a previous exception Y, the InnerException property of X should contain a reference to Y.

Use the InnerException property to obtain the set of exceptions that led to the current exception.

You can create a new exception that catches an earlier exception. The code that handles the second exception can make use of the additional information from the earlier exception to handle the error more appropriately.

Suppose that there is a function that reads a file and formats the data from that file. In this example, as the code tries to read the file, an IOException is thrown. The function catches the IOException and throws a FileNotFoundException. The IOException could be saved in the Exception.InnerException property of the FileNotFoundException, enabling the code that catches the FileNotFoundException to examine what causes the initial error.

The Exception.InnerException property, which holds a reference to the inner exception, is set upon initialization of the exception object.

The following example demonstrates throwing and catching an exception that references an inner exception.

using System;
public class MyAppException:ApplicationException 
{
   public MyAppException (String message) : base (message) 
   {}
   public MyAppException (String message, Exception inner) : base(message,inner) {}	
   }
public class ExceptExample 
{
   public void ThrowInner () 
   {
   throw new MyAppException("ExceptExample inner exception");
   }
   public void CatchInner() 
   {
      try 
      {
      this.ThrowInner();
      }
         catch (Exception e) 
         {
         throw new MyAppException("Error caused by trying ThrowInner.",e);
         }
      }
   }
public class Test 
{
   public static void Main() 
   {
   ExceptExample testInstance = new ExceptExample();
      try 
      {
      testInstance.CatchInner();
      }
         catch(Exception e) 
         {
         Console.WriteLine ("In Main catch block. Caught: {0}", e.Message);
         Console.WriteLine ("Inner Exception is {0}",e.InnerException);
         }
      }
}

    

This code has the following output:

In Main catch block. Caught: Error caused by trying ThrowInner. Inner Exception is MyAppException: ExceptExample inner exception at ExceptExample.ThrowInner() at ExceptExample.CatchInner()

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Summary

Gets the error message that explains the reason for the exception.

C# Syntax:

public override string Message {get;}

If no message was supplied to the constructor for the current exception, this property returns a system-supplied error message. If the FileLoadException.FileName property is not null, the message includes the file name.

This property is read-only.

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Inherited
See base class member description: System.Exception.Source

Summary

Gets or sets the name of the application or the object that causes the error.

C# Syntax:

public virtual string Source {get; set;}

If Exception.Source is not set, the name of the assembly where the exception originated is returned.

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Inherited
See base class member description: System.Exception.StackTrace

Summary

Gets a string representation of the frames on the call stack at the time the current exception was thrown.

C# Syntax:

public virtual string StackTrace {get;}

The execution stack keeps track of all the methods that are in execution at a given instant. A trace of the method calls is called a stack trace. The stack trace listing provides a means to follow the call sequence to the line number in the method where the exception occurs.

StackTrace may not report as many method calls as expected, due to code transformations, such as inlining, that occur during optimization.

Notes to inheritors: The StackTrace property is overridden in classes that require control over the stack trace content or format.

By default, the stack trace is captured immediately before an exception object is thrown. Use Environment.StackTrace to get stack trace information when no exception is being thrown.

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Inherited
See base class member description: System.Exception.TargetSite

Summary

Gets the method that throws the current exception.

C# Syntax:

public MethodBase TargetSite {get;}

If the method that throws this exception is not available and the stack trace is not a null reference (not set or empty), Exception.TargetSite obtains the method from the stack trace. If the stack trace is a null reference , Exception.TargetSite also returns a null reference.

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Inherited
See base class member description: System.Object.Equals

C# Syntax:

public virtual bool Equals(    object obj );

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.Finalize

C# Syntax:

~FileNotFoundException();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Exception.GetBaseException

Summary

When overridden in a derived class, returns the Exception that is the root cause of one or more subsequent exceptions.

C# Syntax:

public virtual Exception GetBaseException();

Return Value:

The first exception thrown in a chain of exceptions. If the Exception.InnerException property of the current exception is a null reference (not set or empty), this property returns the current exception.

A chain of exceptions consists of a set of exceptions such that each exception in the chain was thrown as a direct result of the exception referenced in its InnerException property. For a given chain, there can be exactly one exception that is the root cause of all other exceptions in the chain. This exception is called the base exception and its InnerException property always contains a null reference.

For all exceptions in a chain of exceptions, the GetBaseException method must return the same object (the base exception).

Use the GetBaseException method when you want to find the root cause of an exception but do not need information about exceptions that may have occurred between the current exception and the first exception.

Notes to inheritors: The GetBaseException method is overridden in classes that require control over the exception content or format.

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Inherited
See base class member description: System.Object.GetHashCode

C# Syntax:

public virtual int GetHashCode();

For more information on members inherited from System.Object click on the link above.

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Summary

Sets the SerializationInfo object with the file name and additional exception information.

C# Syntax:

public override void GetObjectData(    SerializationInfo info,    StreamingContext context );

info

The SerializationInfo that holds the serialized object data about the exception being thrown.

context

The StreamingContext that contains contextual information about the source or destination.

Implements:

ISerializable.GetObjectData

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Inherited
See base class member description: System.Object.GetType

C# Syntax:

public Type GetType();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.MemberwiseClone

C# Syntax:

protected object MemberwiseClone();

For more information on members inherited from System.Object click on the link above.

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Summary

Returns the fully qualified name of this exception and possibly the error message, the name of the inner exception, and the stack trace.

C# Syntax:

public override string ToString();

Return Value:

A string containing the fully qualified name of this exception and possibly the error message, the name of the inner exception, and the stack trace.

This method overrides Object.ToString.

The string representation returned by this method includes the name of the exception, the value of the FileNotFoundException.Message property, the result of calling ToString on the inner exception, the value of the FileNotFoundException.FileName property, and the result of calling Environment.StackTrace. If any of these members is a null reference, its value is not included in the returned string.

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