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EventRegistrationToken Struct


Represents a reference to a delegate that receives change notifications.

.NET When programming with .NET, this type is hidden. For advanced scenarios, use System.Runtime.InteropServices.WindowsRuntime.EventRegistrationToken instead.

C++/WinRT In the C++/WinRT language projection, this type appears as winrt::event_token.

public value class EventRegistrationToken
/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.FoundationContract, 65536)]
struct EventRegistrationToken
[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.FoundationContract), 65536)]
public struct EventRegistrationToken
var eventRegistrationToken = {
value : /* Your value */
Public Structure EventRegistrationToken

Windows requirements

Device family
Windows 10 (introduced in 10.0.10240.0)
API contract
Windows.Foundation.FoundationContract (introduced in v1.0)


When programming with .NET, this type is hidden and developers that need an event registration token for advanced event scenarios should use the System.Runtime.InteropServices.WindowsRuntime.EventRegistrationToken type. For most app code, you won't need EventRegistrationToken (or event registration tokens) at all, because the add/remove syntax for C# and Visual Basic languages enables the compiler to generate the registration tokens from a simpler syntax.

In the event subscription model, a delegate registers to receive change notifications from a specified object such as a collection. The EventRegistrationToken is used to remove the delegate as a subscriber of change notifications when notifications are no longer needed.



The reference to the delegate. A valid reference will not have a value of zero.

Applies to

See also