UserState Property
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AsyncCompletedEventArgs.UserState Property

Gets the unique identifier for the asynchronous task.

Namespace:  System.ComponentModel
Assembly:  System (in System.dll)

member UserState : Object

Property Value

Type: System.Object
An object reference that uniquely identifies the asynchronous task; otherwise, a null reference (Nothing in Visual Basic) if no value has been set.

If a class supports multiple asynchronous methods, or multiple invocations of a single method, you can determine which task raised the MethodNameCompleted event by checking the value of the UserState property. Your code will need track these tokens, known as task IDs, as their corresponding asynchronous tasks start and complete.

The value of this property is set during the original call to the asynchronous method that started the task.

The following code example demonstrates using an AsyncOperation to track the lifetime of asynchronous operations. This code example is part of a larger example provided for the System.ComponentModel.AsyncOperationManager class.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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