System.Runtime.Remoting.Contexts.Context Class

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

Summary

Defines an environment for the objects that are resident inside it and for which a policy can be enforced.

C# Syntax:

public class Context

A context is an ordered sequence of properties that define an environment for the objects resident inside it. Contexts get created during the activation process for objects that are configured to require certain automatic services such synchronization, transactions, just-in-time activation, security, and so on. Multiple objects can live inside a context.

Classes are marked with ContextAttribute, which provide the usage rules. Whenever a new object is instantiated, the .NET Framework finds a compatible or creates a new Context for the object. Once an object is placed in a context, it stays in it for life. Classes that can be bound to a context are called context-bound classes. When accessed from another context such classes are referenced directly using a proxy. Any call from an object in one context to an object in another context will go through a context proxy and be affected by the policy that the combined context properties enforce.

A new object's context is generally chosen based on meta-data attributes on the class. This mechanism is extensible through custom attributes. These are known as static context properties, which are compiled into the class meta-data. Dynamic (also known as configuration) context properties can be applied and configured by administrators.

For more information on contexts see the conceptual topic at MSDN: boundariesprocessesapplicationdomainscontexts.

System.Runtime.Remoting.Contexts Namespace

System.Runtime.Remoting.Contexts.Context Member List:

Public Constructors

ctor #1

Default constructor. This constructor is called by derived class constructors to initialize state in this type. Initializes a new instance of the Context class.

Public Properties

ContextID	Read-only Gets the context ID for the current Context.
ContextProperties	Read-only Gets the array of current context properties.
DefaultContext	Read-only Gets the default context for the current AppDomain.

Public Methods

AllocateDataSlot	Allocates an un-named data slot.
AllocateNamedDataSlot	Allocates a named data slot.
DoCallBack	Executes code in another Context.
Equals (inherited from System.Object)	See base class member description: System.Object.Equals Derived from System.Object, the primary base class for all objects.
FreeNamedDataSlot	Frees a named data slot on all the contexts.
Freeze	Freezes the context, making it impossible to add or remove context properties from the current Context.
GetData	Retrieves the value from the specified slot on the current context.
GetHashCode (inherited from System.Object)	See base class member description: System.Object.GetHashCode Derived from System.Object, the primary base class for all objects.
GetNamedDataSlot	Looks up a named data slot.
GetProperty	Returns a specific context property specified by name.
GetType (inherited from System.Object)	See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects.
RegisterDynamicProperty	Registers a dynamic property implementing IDynamicProperty interface with the remoting service.
SetData	Sets the data in the specified slot on the current context.
SetProperty	Sets a specific context property by name.
ToString	Overridden: Returns a String representation of the current context.
UnregisterDynamicProperty	Unregisters a dynamic property implementing IDynamicProperty.

Protected Methods

Finalize	Overridden: Cleans up the backing objects for the nondefault contexts.
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.Runtime.Remoting.Contexts.Context

System.Runtime.Remoting.Contexts.Context Member Details

Summary

Initializes a new instance of the Context class.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

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

C# Syntax:

public Context();

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Summary

Gets the context ID for the current Context.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public virtual int ContextID {get;}

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Summary

Gets the array of current context properties.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public virtual IContextProperty[] ContextProperties {get;}

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Summary

Gets the default context for the current AppDomain.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public static Context DefaultContext {get;}

Every thread in an application domain for which a context is not explicitly set is considered to be running in the default context.

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Summary

Allocates an un-named data slot.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public static LocalDataStoreSlot AllocateDataSlot();

Return Value:

A local data slot.

The slot is allocated on all the contexts.

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Summary

Allocates a named data slot.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public static LocalDataStoreSlot AllocateNamedDataSlot(    string name );

name

The required for the data slot.

Return Value:

A local data slot object.

The slot is allocated on all the contexts. Named data slots are "public" and can be manipulated by anyone.

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Summary

Executes code in another Context.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public void DoCallBack(    CrossContextDelegate deleg );

deleg

The delegate used to request the callback.

A callback can be done by calling the Context.DoCallBack method on it by passing in a delegate. The delegate is used to request a callback. The delegate must be of type CrossContextDelegate.

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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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Summary

Cleans up the backing objects for the nondefault contexts.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

~Context();

For default contexts backing objects are cleaned up during AppDomain shutdown.

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Summary

Frees a named data slot on all the contexts.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public static void FreeNamedDataSlot(    string name );

name

The name of the data slot to free.

Named data slots are "public" and can be manipulated by anyone.

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Summary

Freezes the context, making it impossible to add or remove context properties from the current Context.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public virtual void Freeze();

Exceptions

Exception Type	Condition
InvalidOperationException	The Context is already frozen.

Context properties cannot be added after the context has been frozen.

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Summary

Retrieves the value from the specified slot on the current context.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public static object GetData(    LocalDataStoreSlot slot );

slot

The data slot that contains the data

Return Value:

Returns the data associated with the DataSlot provided

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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

Looks up a named data slot.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public static LocalDataStoreSlot GetNamedDataSlot(    string name );

name

The data slot name.

Return Value:

Retruns a LocalDataSlot.

If the name has not been used, a new slot is allocated. Named data slots are "public" and can be manipulated by anyone.

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Summary

Returns a specific context property specified by name.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public virtual IContextProperty GetProperty(    string name );

name

The name of the property

Return Value:

The specified context property.

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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

Registers a dynamic property implementing IDynamicProperty interface with the remoting service.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public static bool RegisterDynamicProperty(    IDynamicProperty prop,    ContextBoundObject obj,    Context ctx );

prop

The dynamic property to register.

obj

The object/proxy for which the property is registered. The object/proxy for which the property is registered.

ctx

The context for which the property is registered.

Return Value:

true if the property was successfully registered; otherwise, false.

Exceptions

Exception Type	Condition
ArgumentNullException	The prop parameter or its name is null, or it is not dynamic (it does not implement IDynamicProperty).
ArgumentException	Both an object as well as a context are specified (both obj and ctx parameters are not null).

Based on the obj and ctx parameters, the property is asked to contribute a sink that is placed at some location in the path of remoting calls. If multiple properties are registered, their sinks will be called in an arbitrary order that can change between calls.

If the obj parameter is not null then if it is a proxy, all calls made on the proxy are intercepted. Otherwise, if obj is a real object, all calls on the object are intercepted. The ctx argument must be null.

If the ctx parameter is not null then the obj parameter must be null and all calls entering and leaving the context are intercepted.

If both ctx and obj parameters are null, then all calls entering and leaving all contexts are intercepted.

SecurityPermission for pluging code into the common language runtime infrastructure. Associated enumeration: SecurityPermissionFlag.Infrastructure.

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Summary

Sets the data in the specified slot on the current context.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public static void SetData(    LocalDataStoreSlot slot,    object data );

slot

The data slot where the data is to be added.

data

The data that is to be added.

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Summary

Sets a specific context property by name.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public virtual void SetProperty(    IContextProperty prop );

prop

Actual context property.

Exceptions

Exception Type	Condition
InvalidOperationException	There is an attempt to add properties to the default context.
InvalidOperationException	The context is frozen.
ArgumentNullException	The property or the property name is null.

Adding properties to the default context is not allowed.

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Summary

Returns a String representation of the current context.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public override string ToString();

Return Value:

A String representation of the current context.

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Summary

Unregisters a dynamic property implementing IDynamicProperty.

This type supports the Shared Source CLI infrastructure and is not intended to be used directly from your code.

C# Syntax:

public static bool UnregisterDynamicProperty(    string name,    ContextBoundObject obj,    Context ctx );

name

The name of the dynamic property to unregister.

obj

The object/proxy for which the property is registered.

ctx

The context for which the property is registered.

Return Value:

true if the object was successfully unregistered; otherwise, false.

Exceptions

Exception Type	Condition
ArgumentNullException	The name parameter is null.
ArgumentException	Both an object as well as a context are specified (both obj and ctx parameters are not null).

SecurityPermission for pluging code into the common language runtime infrastructure. Associated enumeration: SecurityPermissionFlag.Infrastructure.

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