TaskExtensions.Unwrap TaskExtensions.Unwrap TaskExtensions.Unwrap TaskExtensions.Unwrap Method

Definition

Überlädt

Unwrap(Task<Task>) Unwrap(Task<Task>) Unwrap(Task<Task>)

Erstellt einen Task für Proxys, der den asynchronen Vorgang eines TryExecuteTaskInline(Task, Boolean) darstellt.Creates a proxy Task that represents the asynchronous operation of a TryExecuteTaskInline(Task, Boolean).

Unwrap<TResult>(Task<Task<TResult>>) Unwrap<TResult>(Task<Task<TResult>>) Unwrap<TResult>(Task<Task<TResult>>) Unwrap<TResult>(Task<Task<TResult>>)

Erstellt einen Proxy-Task, der den asynchronen Vorgang von einem Task<Task<T>> (C#) oder Task (Of Task(Of T)) (Visual Basic) darstellt.Creates a proxy Task that represents the asynchronous operation of a Task<Task<T>> (C#) or Task (Of Task(Of T)) (Visual Basic).

Unwrap(Task<Task>) Unwrap(Task<Task>) Unwrap(Task<Task>)

Erstellt einen Task für Proxys, der den asynchronen Vorgang eines TryExecuteTaskInline(Task, Boolean) darstellt.Creates a proxy Task that represents the asynchronous operation of a TryExecuteTaskInline(Task, Boolean).

public:
[System::Runtime::CompilerServices::Extension]
 static System::Threading::Tasks::Task ^ Unwrap(System::Threading::Tasks::Task<System::Threading::Tasks::Task ^> ^ task);
public static System.Threading.Tasks.Task Unwrap (this System.Threading.Tasks.Task<System.Threading.Tasks.Task> task);
static member Unwrap : System.Threading.Tasks.Task<System.Threading.Tasks.Task> -> System.Threading.Tasks.Task

Parameter

task
Task<Task>

Die zu entpackende Task<Task> (C#) oder Task (Of Task) Visual Basic).The Task<Task> (C#) or Task (Of Task) (Visual Basic) to unwrap.

Gibt zurück

Eine Aufgabe, die den asynchronen Vorgang des angegebenen System.Threading.Tasks.Task(Of Task) darstellt.A Task that represents the asynchronous operation of the provided System.Threading.Tasks.Task(Of Task).

Ausnahmen

Die Ausnahme, die ausgelöst wird, wenn das task-Argument NULL ist.The exception that is thrown if the task argument is null.

Beispiele

Das folgende Beispiel zeigt, wie Sie eine Aufgabe zu entpacken:The following example shows how to unwrap a task:

using System;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;

class UnWrapDemo
{
     // Demonstrated features:
        //		Task.Unwrap()
        // 		Task.Factory.StartNew()
        //		Task.ContinueWith()
        // Expected results:
        // 		Indicates that continuation chains can be set up virtually instantaneously using Unwrap(), and then left to run on their own.
        //      The results of the RemoteIncrement(0) chain and the RemoteIncrement(4) chain may be intermixed with each other.
        //		The results of the sequence that starts with RemoteIncrement(4) are in strict order.
        // Documentation:
        //		http://msdn.microsoft.com/library/dd781129(VS.100).aspx
        // More information:
        //		http://blogs.msdn.com/pfxteam/archive/2009/11/04/9917581.aspx
        // Other notes:
        //		The combination of Task<T>, ContinueWith() and Unwrap() can be particularly useful for setting up a chain of long-running
        //      tasks where each task uses the results of its predecessor.
        static void Main()
        {
            // Invoking individual tasks is straightforward
            Task<int> t1 = RemoteIncrement(0);
            Console.WriteLine("Started RemoteIncrement(0)");

            // Chain together the results of (simulated) remote operations.
            // The use of Unwrap() instead of .Result below prevents this thread from blocking while setting up this continuation chain.
            Task<int> t2 = RemoteIncrement(4)
                .ContinueWith(t => RemoteIncrement(t.Result))			// RemoteIncrement() returns Task<int> so no unwrapping is needed for the first continuation.
                .Unwrap().ContinueWith(t => RemoteIncrement(t.Result))	// ContinueWith() returns Task<Task<int>>. Therefore unwrapping is needed.
                .Unwrap().ContinueWith(t => RemoteIncrement(t.Result))	// and on it goes...
                .Unwrap();
            Console.WriteLine("Started RemoteIncrement(...(RemoteIncrement(RemoteIncrement(4))...)");

            try
            {
                t1.Wait();
                Console.WriteLine("Finished RemoteIncrement(0)\n");

                t2.Wait();
                Console.WriteLine("Finished RemoteIncrement(...(RemoteIncrement(RemoteIncrement(4))...)");
            }
            catch (AggregateException e)
            {
                Console.WriteLine("A task has thrown the following (unexpected) exception:\n{0}", e);
            }

        }
        // This method represents a remote API.
        static Task<int> RemoteIncrement(int n)
        {
            return Task<int>.Factory.StartNew(
                (obj) =>
                {
                    // Simulate a slow operation
                    Thread.Sleep(1 * 1000);

                    int x = (int)obj;
                    Console.WriteLine("Thread={0}, Next={1}", Thread.CurrentThread.ManagedThreadId, ++x);
                    return x;
                },
                n);
        }
      
}

Imports System.Threading
Imports System.Threading.Tasks

Module UnwrapDemo
    ' Demonstrated features:
    '   Task.Unwrap()
    '    Task.Factory.StartNew()
    '   Task.ContinueWith()
    ' Expected results:
    ' 	Indicates that continuation chains can be set up virtually instantaneously using Unwrap(), and then left to run on their own.
    '   The results of the RemoteIncrement(0) chain and the RemoteIncrement(4) chain may be intermixed with each other.
    '   The results of the sequence that starts with RemoteIncrement(4) are in strict order.
    ' Documentation:
    '   http://msdn.microsoft.com/library/dd781129(VS.100).aspx
    ' More information:
    '   http://blogs.msdn.com/pfxteam/archive/2009/11/04/9917581.aspx
    ' Other notes:
    '   The combination of Task<T>, ContinueWith() and Unwrap() can be particularly useful for setting up a chain of long-running
    '   tasks where each task uses the results of its predecessor.

    Sub Main()
        ' Invoking individual tasks is straightforward
        Dim t1 As Task(Of Integer) = RemoteIncrement(0)
        Console.WriteLine("Started RemoteIncrement(0)")

        ' Chain together the results of (simulated) remote operations.
        ' The use of Unwrap() instead of .Result below prevents this thread from blocking while setting up this continuation chain.
        ' RemoteIncrement() returns Task<int> so no unwrapping is needed for the first continuation.
        ' ContinueWith() here returns Task<Task<int>>. Therefore unwrapping is needed.
        ' and on it goes...
        Dim t2 As Task(Of Integer) = RemoteIncrement(4).ContinueWith(Function(t) RemoteIncrement(t.Result)).Unwrap().ContinueWith(Function(t) RemoteIncrement(t.Result)).Unwrap().ContinueWith(Function(t) RemoteIncrement(t.Result)).Unwrap()
        Console.WriteLine("Started RemoteIncrement(...(RemoteIncrement(RemoteIncrement(4))...)")

        Try
            t1.Wait()
            Console.WriteLine("Finished RemoteIncrement(0)" & vbLf)

            t2.Wait()
            Console.WriteLine("Finished RemoteIncrement(...(RemoteIncrement(RemoteIncrement(4))...)")
        Catch e As AggregateException
            Console.WriteLine("A task has thrown the following (unexpected) exception:" & vbLf & "{0}", e)

        End Try
    End Sub

    ' This method represents a remote API.
    Function RemoteIncrement(ByVal n As Integer) As Task(Of Integer)
        Return Task(Of Integer).Factory.StartNew(Function(obj)
                                                     ' Simulate a slow operation
                                                     Thread.Sleep(1 * 1000)

                                                     Dim x As Integer = CInt(obj)
                                                     Console.WriteLine("Thread={0}, Next={1}", Thread.CurrentThread.ManagedThreadId, System.Threading.Interlocked.Increment(x))
                                                     Return x
                                                 End Function, n)
    End Function


End Module

Hinweise

Es ist häufig nützlich, um eine Aufgabe von zurückgeben kann eine Task<TResult>, wobei die innere Aufgabe Arbeit, die als Teil des äußeren repräsentiert Task<TResult>.It is often useful to be able to return a Task from a Task<TResult>, where the inner Task represents work done as part of the outer Task<TResult>. Jedoch, da sonst eine Task<Task> (c#) oder Task (Of Task) (Visual Basic), die, wenn Sie nicht sorgfältig behandelt kann zu unerwartetem Verhalten führen.However, doing so results in a Task<Task> (C#) or Task (Of Task) (Visual Basic), which, if not dealt with carefully, could produce unexpected behavior. Unwrap-löst dieses Problem durch Erstellen eines Proxy-Aufgabe, die den gesamten asynchronen Vorgang einer solchen Aufgabe darstellt.Unwrap solves this problem by creating a proxy Task that represents the entire asynchronous operation of such a task.

Siehe auch

Unwrap<TResult>(Task<Task<TResult>>) Unwrap<TResult>(Task<Task<TResult>>) Unwrap<TResult>(Task<Task<TResult>>) Unwrap<TResult>(Task<Task<TResult>>)

Erstellt einen Proxy-Task, der den asynchronen Vorgang von einem Task<Task<T>> (C#) oder Task (Of Task(Of T)) (Visual Basic) darstellt.Creates a proxy Task that represents the asynchronous operation of a Task<Task<T>> (C#) or Task (Of Task(Of T)) (Visual Basic).

public:
generic <typename TResult>
[System::Runtime::CompilerServices::Extension]
 static System::Threading::Tasks::Task<TResult> ^ Unwrap(System::Threading::Tasks::Task<System::Threading::Tasks::Task<TResult> ^> ^ task);
public static System.Threading.Tasks.Task<TResult> Unwrap<TResult> (this System.Threading.Tasks.Task<System.Threading.Tasks.Task<TResult>> task);
static member Unwrap : System.Threading.Tasks.Task<System.Threading.Tasks.Task<'Result>> -> System.Threading.Tasks.Task<'Result>
<Extension()>
Public Function Unwrap(Of TResult) (task As Task(Of Task(Of TResult))) As Task(Of TResult)

Typparameter

TResult

Der Typ des Aufgabenergebnisses.The type of the task's result.

Parameter

task
Task<Task<TResult>>

Die zu entpackende Task<Task<T>> (C#) oder Task (Of Task(Of T)) Visual Basic).The Task<Task<T>> (C#) or Task (Of Task(Of T)) (Visual Basic) to unwrap.

Gibt zurück

Ein Task, der den asynchronen Vorgang des bereitgestellten Task<Task<T>> (C#) oder Task (Of Task(Of T)) (Visual Basic) darstellt.A Task that represents the asynchronous operation of the provided Task<Task<T>> (C#) or Task (Of Task(Of T)) (Visual Basic).

Ausnahmen

Die Ausnahme, die ausgelöst wird, wenn das task-Argument NULL ist.The exception that is thrown if the task argument is null.

Hinweise

Es ist häufig nützlich, um zurückgeben zu können eine Task aus einer Task, wobei die innere Task stellt Arbeit, die als Teil des äußeren Task.It is often useful to be able to return a Task from a Task, where the inner Task represents work done as part of the outer Task. Jedoch, da sonst eine Task<Task<T>> (c#) oder Task (Of Task(Of T)) (Visual Basic), die, wenn Sie nicht sorgfältig behandelt kann zu unerwartetem Verhalten führen.However, doing so results in a Task<Task<T>> (C#) or Task (Of Task(Of T)) (Visual Basic), which, if not dealt with carefully, could produce unexpected behavior. Unwrap-löst dieses Problem durch Erstellen eines Proxys Task<TResult> , das den gesamten asynchronen Vorgang eines solchen darstellt. ein Task<Task<T>> (c#) oder Task (Of Task(Of T)) (Visual Basic).Unwrap solves this problem by creating a proxy Task<TResult> that represents the entire asynchronous operation of such a Task<Task<T>> (C#) or Task (Of Task(Of T)) (Visual Basic).

Siehe auch

Gilt für: