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TaskFactory.FromAsync<TResult> Method (IAsyncResult, Func<IAsyncResult, TResult>, TaskCreationOptions)

Creates a Task<TResult> that executes an end method function when a specified IAsyncResult completes.

Namespace:  System.Threading.Tasks
Assemblies:   mscorlib (in mscorlib.dll)
  System.Threading.Tasks (in System.Threading.Tasks.dll)

public Task<TResult> FromAsync<TResult>(
	IAsyncResult asyncResult,
	Func<IAsyncResult, TResult> endMethod,
	TaskCreationOptions creationOptions
)

Type Parameters

TResult

The type of the result available through the Task<TResult>.

Parameters

asyncResult
Type: System.IAsyncResult

The IAsyncResult whose completion should trigger the processing of the endMethod.

endMethod
Type: System.Func<IAsyncResult, TResult>

The function delegate that processes the completed asyncResult.

creationOptions
Type: System.Threading.Tasks.TaskCreationOptions

The TaskCreationOptions value that controls the behavior of the created Task<TResult>.

Return Value

Type: System.Threading.Tasks.Task<TResult>
A Task<TResult> that represents the asynchronous operation.

ExceptionCondition
ArgumentNullException

The exception that is thrown when the asyncResult argument is null.

-or-

The exception that is thrown when the endMethod argument is null.

ArgumentOutOfRangeException

The exception that is thrown when the creationOptions argument specifies an invalid TaskCreationOptions value. The exception that is thrown when the creationOptions argument specifies an invalid TaskCreationOptions value. For more information, see the Remarks for FromAsync

TipTip

The FromAsync overloads that take an asyncResult parameter are not as efficient as the overloads that take a beginMethod parameter. If performance is an issue, use the overloads that provide the beginMethod/endMethod pattern.

.NET Framework

Supported in: 4.6, 4.5, 4

.NET Framework Client Profile

Supported in: 4

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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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