Task.WaitAll 方法

public:
 static void WaitAll(... cli::array <System::Threading::Tasks::Task ^> ^ tasks);

public static void WaitAll (params System.Threading.Tasks.Task[] tasks);

static member WaitAll : System.Threading.Tasks.Task[] -> unit

Public Shared Sub WaitAll (ParamArray tasks As Task())

參數

例外狀況

範例

下列範例會啟動10個工作，每個工作都會以狀態物件的形式傳遞索引。The following example starts 10 tasks, each of which is passed an index as a state object. 具有從二到五之索引的工作會擲回例外狀況。Tasks with an index from two to five throw exceptions. 方法的呼叫會 WaitAll 包裝物件中的所有例外狀況 AggregateException ，並將其傳播至呼叫的執行緒。The call to the WaitAll method wraps all exceptions in an AggregateException object and propagates it to the calling thread.

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;

class Example
{
    static void Main()
    {
        var tasks = new List<Task<int>>();
         
        // Define a delegate that prints and returns the system tick count
        Func<object, int> action = (object obj) =>
        {
            int i = (int)obj;

            // Make each thread sleep a different time in order to return a different tick count
            Thread.Sleep(i * 100);

            // The tasks that receive an argument between 2 and 5 throw exceptions
            if (2 <= i && i <= 5)
            {
                throw new InvalidOperationException("SIMULATED EXCEPTION");
            }

            int tickCount = Environment.TickCount;
            Console.WriteLine("Task={0}, i={1}, TickCount={2}, Thread={3}", Task.CurrentId, i, tickCount, Thread.CurrentThread.ManagedThreadId);

            return tickCount;
        };

        // Construct started tasks
        for (int i = 0; i < 10; i++)
        {
            int index = i;
            tasks.Add(Task<int>.Factory.StartNew(action, index));
        }

        try
        {
            // Wait for all the tasks to finish.
            Task.WaitAll(tasks.ToArray());

            // We should never get to this point
            Console.WriteLine("WaitAll() has not thrown exceptions. THIS WAS NOT EXPECTED.");
        }
        catch (AggregateException e)
        {
            Console.WriteLine("\nThe following exceptions have been thrown by WaitAll(): (THIS WAS EXPECTED)");
            for (int j = 0; j < e.InnerExceptions.Count; j++)
            {
                Console.WriteLine("\n-------------------------------------------------\n{0}", e.InnerExceptions[j].ToString());
            }
        }
    }
}
// The example displays output like the following:
//     Task=1, i=0, TickCount=1203822250, Thread=3
//     Task=2, i=1, TickCount=1203822359, Thread=4
//     Task=7, i=6, TickCount=1203823484, Thread=3
//     Task=8, i=7, TickCount=1203823890, Thread=4
//     Task=9, i=8, TickCount=1203824296, Thread=3
//     Task=10, i=9, TickCount=1203824796, Thread=4
//     
//     The following exceptions have been thrown by WaitAll(): (THIS WAS EXPECTED)
//     
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()
//     
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()
//     
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()
//     
//     -------------------------------------------------
//     System.InvalidOperationException: SIMULATED EXCEPTION
//        at Example.<Main>b__0(Object obj)
//        at System.Threading.Tasks.Task`1.InnerInvoke()
//        at System.Threading.Tasks.Task.Execute()

Imports System.Collections.Generic
Imports System.Threading
Imports System.Threading.Tasks

Module WaitAllDemo
    Sub Main()
        Dim tasks As New List(Of Task(Of Integer))()
        ' Define a delegate that prints and returns the system tick count
        Dim action As Func(Of Object, Integer) = Function(obj As Object)
                                                     Dim i As Integer = CInt(obj)

                                                     ' Make each thread sleep a different time in order to return a different tick count
                                                     Thread.Sleep(i * 100)

                                                     ' The tasks that receive an argument between 2 and 5 throw exceptions
                                                     If 2 <= i AndAlso i <= 5 Then
                                                         Throw New InvalidOperationException("SIMULATED EXCEPTION")
                                                     End If

                                                     Dim tickCount As Integer = Environment.TickCount
                                                     Console.WriteLine("Task={0}, i={1}, TickCount={2}, Thread={3}", Task.CurrentId, i, tickCount, Thread.CurrentThread.ManagedThreadId)

                                                     Return tickCount
                                                 End Function

        ' Construct started tasks
        For i As Integer = 0 To 9
            Dim index As Integer = i
            tasks.Add(Task(Of Integer).Factory.StartNew(action, index))
        Next

        Try
            ' Wait for all the tasks to finish.
            Task.WaitAll(tasks.ToArray())

            ' We should never get to this point
            Console.WriteLine("WaitAll() has not thrown exceptions. THIS WAS NOT EXPECTED.")
        Catch e As AggregateException
            Console.WriteLine(vbLf & "The following exceptions have been thrown by WaitAll(): (THIS WAS EXPECTED)")
            For j As Integer = 0 To e.InnerExceptions.Count - 1
                Console.WriteLine(vbLf & "-------------------------------------------------" & vbLf & "{0}", e.InnerExceptions(j).ToString())
            Next
        End Try
    End Sub
End Module
' The example displays output like the following:
'     Task=1, i=0, TickCount=1203822250, Thread=3
'     Task=2, i=1, TickCount=1203822359, Thread=4
'     Task=7, i=6, TickCount=1203823484, Thread=3
'     Task=8, i=7, TickCount=1203823890, Thread=4
'     Task=9, i=8, TickCount=1203824296, Thread=3
'     Task=10, i=9, TickCount=1203824796, Thread=4
'     
'     The following exceptions have been thrown by WaitAll(): (THIS WAS EXPECTED)
'     
'     -------------------------------------------------
'     System.InvalidOperationException: SIMULATED EXCEPTION
'        at Example.<Main>b__0(Object obj)
'        at System.Threading.Tasks.Task`1.InnerInvoke()
'        at System.Threading.Tasks.Task.Execute()
'     
'     -------------------------------------------------
'     System.InvalidOperationException: SIMULATED EXCEPTION
'        at Example.<Main>b__0(Object obj)
'        at System.Threading.Tasks.Task`1.InnerInvoke()
'        at System.Threading.Tasks.Task.Execute()
'     
'     -------------------------------------------------
'     System.InvalidOperationException: SIMULATED EXCEPTION
'        at Example.<Main>b__0(Object obj)
'        at System.Threading.Tasks.Task`1.InnerInvoke()
'        at System.Threading.Tasks.Task.Execute()
'     
'     -------------------------------------------------
'     System.InvalidOperationException: SIMULATED EXCEPTION
'        at Example.<Main>b__0(Object obj)
'        at System.Threading.Tasks.Task`1.InnerInvoke()
'        at System.Threading.Tasks.Task.Execute()

public:
 static bool WaitAll(cli::array <System::Threading::Tasks::Task ^> ^ tasks, int millisecondsTimeout);

public static bool WaitAll (System.Threading.Tasks.Task[] tasks, int millisecondsTimeout);

static member WaitAll : System.Threading.Tasks.Task[] * int -> bool

Public Shared Function WaitAll (tasks As Task(), millisecondsTimeout As Integer) As Boolean

參數

傳回

Boolean

如果所有 true 執行個體在指定的時間內執行完成，則為 Task，否則為 false。true if all of the Task instances completed execution within the allotted time; otherwise, false.

例外狀況

public:
 static void WaitAll(cli::array <System::Threading::Tasks::Task ^> ^ tasks, System::Threading::CancellationToken cancellationToken);

public static void WaitAll (System.Threading.Tasks.Task[] tasks, System.Threading.CancellationToken cancellationToken);

static member WaitAll : System.Threading.Tasks.Task[] * System.Threading.CancellationToken -> unit

Public Shared Sub WaitAll (tasks As Task(), cancellationToken As CancellationToken)

參數

例外狀況

備註

cancellationToken引數用來取消等候作業。The cancellationToken argument is used to cancel the wait operation. 取消工作是一項不同的作業，並 AggregateException 以上述方式發出信號。Cancellation of the tasks is a distinct operation, and is signaled by the AggregateException as noted above.

public:
 static bool WaitAll(cli::array <System::Threading::Tasks::Task ^> ^ tasks, TimeSpan timeout);

public static bool WaitAll (System.Threading.Tasks.Task[] tasks, TimeSpan timeout);

static member WaitAll : System.Threading.Tasks.Task[] * TimeSpan -> bool

Public Shared Function WaitAll (tasks As Task(), timeout As TimeSpan) As Boolean

參數

傳回

Boolean

如果所有 true 執行個體在指定的時間內執行完成，則為 Task，否則為 false。true if all of the Task instances completed execution within the allotted time; otherwise, false.

例外狀況

public:
 static bool WaitAll(cli::array <System::Threading::Tasks::Task ^> ^ tasks, int millisecondsTimeout, System::Threading::CancellationToken cancellationToken);

public static bool WaitAll (System.Threading.Tasks.Task[] tasks, int millisecondsTimeout, System.Threading.CancellationToken cancellationToken);

static member WaitAll : System.Threading.Tasks.Task[] * int * System.Threading.CancellationToken -> bool

Public Shared Function WaitAll (tasks As Task(), millisecondsTimeout As Integer, cancellationToken As CancellationToken) As Boolean

參數

傳回

Boolean

如果所有 true 執行個體在指定的時間內執行完成，則為 Task，否則為 false。true if all of the Task instances completed execution within the allotted time; otherwise, false.

例外狀況

備註

cancellationToken引數用來取消等候作業。The cancellationToken argument is used to cancel the wait operation. 取消工作是一項不同的作業，並由上面所述的方式發出信號 AggregateException 。Cancellation of the tasks is a distinct operation, and is signaled by the AggregateException noted above.