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

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
)

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.

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.

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

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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