WindowsRuntimeSystemExtensions.AsAsyncAction Method

.NET Framework 4.5

Returns a Windows Runtime asynchronous action that represents a started task.

Namespace:  System
Assembly:  System.Runtime.WindowsRuntime (in System.Runtime.WindowsRuntime.dll)

static member AsAsyncAction : 
        source:Task -> IAsyncAction


Type: System.Threading.Tasks.Task

The started task.

Return Value

Type: IAsyncAction
A Windows.Foundation.IAsyncAction instance that represents the started task.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type Task. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).


source is a null reference (Nothing in Visual Basic).


source is an unstarted task.

Use this method when you want to pass a task to a Windows Runtime method that takes an asynchronous action.

The AsyncInfo class provides static methods (Shared methods in Visual Basic) that create and start Windows Runtime asynchronous actions that represent tasks that can respond to cancellation requests and report progress.

.NET Framework

Supported in: 4.5

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone Silverlight 8

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012

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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