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

 

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

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

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

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>.

scheduler
Type: System.Threading.Tasks.TaskScheduler

The TaskScheduler that is used to schedule the task that executes the end method.

Return Value

Type: System.Threading.Tasks.Task<TResult>

A Task<TResult> that represents the asynchronous operation.

Type Parameters

TResult

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

Exception Condition
ArgumentNullException

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

-or-

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

-or-

The exception that is thrown when the scheduler 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

System_CAPS_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.

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 5.0
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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