CancellationToken.Register Method

Definition

Namespace:

System.Threading

Assembly:

System.Runtime.dll

Registers a delegate that will be called when this CancellationToken is canceled.

Overloads

Register(Action)	Registers a delegate that will be called when this CancellationToken is canceled.
Register(Action, Boolean)	Registers a delegate that will be called when this CancellationToken is canceled.
Register(Action<Object,CancellationToken>, Object)	Registers a delegate that will be called when this CancellationToken is canceled.
Register(Action<Object>, Object)	Registers a delegate that will be called when this CancellationToken is canceled.
Register(Action<Object>, Object, Boolean)	Registers a delegate that will be called when this CancellationToken is canceled.

Register(Action)

Source:

CancellationToken.cs

Registers a delegate that will be called when this CancellationToken is canceled.

public:
 System::Threading::CancellationTokenRegistration Register(Action ^ callback);

public System.Threading.CancellationTokenRegistration Register (Action callback);

member this.Register : Action -> System.Threading.CancellationTokenRegistration

Public Function Register (callback As Action) As CancellationTokenRegistration

Parameters

callback

Action

The delegate to be executed when the CancellationToken is canceled.

Returns

CancellationTokenRegistration

The CancellationTokenRegistration instance that can be used to unregister the callback.

Exceptions

ObjectDisposedException

The associated CancellationTokenSource has been disposed.

ArgumentNullException

callback is null.

Remarks

If this token is already in the canceled state, the delegate will be run immediately and synchronously. Any exception the delegate generates will be propagated out of this method call.

The current ExecutionContext is captured along with the delegate and will be used when executing it.

The current SynchronizationContext is not captured.

See also

• Cancellation
• Task Cancellation
• How to: Register Callbacks for Cancellation Requests

Register(Action, Boolean)

Source:

CancellationToken.cs

Registers a delegate that will be called when this CancellationToken is canceled.

public:
 System::Threading::CancellationTokenRegistration Register(Action ^ callback, bool useSynchronizationContext);

public System.Threading.CancellationTokenRegistration Register (Action callback, bool useSynchronizationContext);

member this.Register : Action * bool -> System.Threading.CancellationTokenRegistration

Public Function Register (callback As Action, useSynchronizationContext As Boolean) As CancellationTokenRegistration

Parameters

callback

Action

The delegate to be executed when the CancellationToken is canceled.

useSynchronizationContext

Boolean

A value that indicates whether to capture the current SynchronizationContext and use it when invoking the callback.

Returns

CancellationTokenRegistration

The CancellationTokenRegistration instance that can be used to unregister the callback.

Exceptions

ObjectDisposedException

The associated CancellationTokenSource has been disposed.

ArgumentNullException

callback is null.

Remarks

If this token is already in the canceled state, the delegate will be run immediately and synchronously. Any exception the delegate generates will be propagated out of this method call.

The current ExecutionContext is captured along with the delegate and will be used when executing it.

If useSynchronizationContext is true, the current SynchronizationContext, if one exists, is also captured along with the delegate and will be used when executing it. Otherwise, SynchronizationContext is not captured.

See also

• Cancellation
• Task Cancellation
• How to: Register Callbacks for Cancellation Requests

Register(Action<Object,CancellationToken>, Object)

Source:

CancellationToken.cs

Registers a delegate that will be called when this CancellationToken is canceled.

public:
 System::Threading::CancellationTokenRegistration Register(Action<System::Object ^, System::Threading::CancellationToken> ^ callback, System::Object ^ state);

public System.Threading.CancellationTokenRegistration Register (Action<object?,System.Threading.CancellationToken> callback, object? state);

member this.Register : Action<obj, System.Threading.CancellationToken> * obj -> System.Threading.CancellationTokenRegistration

Public Function Register (callback As Action(Of Object, CancellationToken), state As Object) As CancellationTokenRegistration

Parameters

callback

Action<Object,CancellationToken>

The delegate to be executed when the CancellationToken is canceled.

state

Object

The state to pass to the callback when the delegate is invoked. This may be null.

Returns

CancellationTokenRegistration

The CancellationTokenRegistration instance that can be used to unregister the callback.

Exceptions

ArgumentNullException

callback is null.

Remarks

If this token is already in the canceled state, the delegate will be run immediately and synchronously. Any exception the delegate generates will be propagated out of this method call. The current ExecutionContext, if one exists, is captured along with the delegate and is used when executing it. The current SynchronizationContext is not captured.

Register(Action<Object>, Object)

Source:

CancellationToken.cs

Registers a delegate that will be called when this CancellationToken is canceled.

public:
 System::Threading::CancellationTokenRegistration Register(Action<System::Object ^> ^ callback, System::Object ^ state);

public System.Threading.CancellationTokenRegistration Register (Action<object?> callback, object? state);

member this.Register : Action<obj> * obj -> System.Threading.CancellationTokenRegistration

Public Function Register (callback As Action(Of Object), state As Object) As CancellationTokenRegistration

Parameters

callback

Action<Object>

The delegate to be executed when the CancellationToken is canceled.

state

Object

The state to pass to the callback when the delegate is invoked. This may be null.

Returns

CancellationTokenRegistration

The CancellationTokenRegistration instance that can be used to unregister the callback.

Exceptions

ObjectDisposedException

The associated CancellationTokenSource has been disposed.

ArgumentNullException

callback is null.

Remarks

If this token is already in the canceled state, the delegate will be run immediately and synchronously. Any exception the delegate generates will be propagated out of this method call.

The current ExecutionContext is captured along with the delegate and will be used when executing it.

The current SynchronizationContext is not captured.

See also

• Cancellation
• Task Cancellation
• How to: Register Callbacks for Cancellation Requests

Register(Action<Object>, Object, Boolean)

Source:

CancellationToken.cs

Registers a delegate that will be called when this CancellationToken is canceled.

public:
 System::Threading::CancellationTokenRegistration Register(Action<System::Object ^> ^ callback, System::Object ^ state, bool useSynchronizationContext);

public System.Threading.CancellationTokenRegistration Register (Action<object?> callback, object? state, bool useSynchronizationContext);

member this.Register : Action<obj> * obj * bool -> System.Threading.CancellationTokenRegistration

Public Function Register (callback As Action(Of Object), state As Object, useSynchronizationContext As Boolean) As CancellationTokenRegistration

Parameters

callback

Action<Object>

The delegate to be executed when the CancellationToken is canceled.

state

Object

The state to pass to the callback when the delegate is invoked. This may be null.

useSynchronizationContext

Boolean

A Boolean value that indicates whether to capture the current SynchronizationContext and use it when invoking the callback.

Returns

CancellationTokenRegistration

The CancellationTokenRegistration instance that can be used to unregister the callback.

Exceptions

ObjectDisposedException

The associated CancellationTokenSource has been disposed.

ArgumentNullException

callback is null.

Remarks

If this token is already in the canceled state, the delegate will be run immediately and synchronously. Any exception the delegate generates will be propagated out of this method call.

The current ExecutionContext is captured along with the delegate and will be used when executing it.

If useSynchronizationContext is true, the current SynchronizationContext, if one exists, is also captured along with the delegate and will be used when executing it. Otherwise, SynchronizationContext is not captured.

See also

• Cancellation
• Task Cancellation
• How to: Register Callbacks for Cancellation Requests