• Article

TaskFactory.ContinueWhenAll Method (array<Task[], Action<array<Task[]>)

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Creates a continuation Task that will be started upon the completion of a set of provided Tasks.

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

Syntax

'Declaration
Public Function ContinueWhenAll ( _
    tasks As Task(), _
    continuationAction As Action(Of Task()) _
) As Task

public Task ContinueWhenAll(
    Task[] tasks,
    Action<Task[]> continuationAction
)

Parameters

  • continuationAction
    Type: System.Action<array<Task[]>
    The action delegate to execute when all tasks in the tasks array have completed.

Return Value

Type: System.Threading.Tasks.Task
The new continuation Task.

Exceptions

Exception Condition
ObjectDisposedException

The exception that is thrown when one of the elements in the tasks array has been disposed.
ArgumentNullException

The exception that is thrown when the tasks array is null.

-or-

The exception that is thrown when the continuationAction argument is null.
ArgumentException

The exception that is thrown when the tasks array contains a null value.

-or-

The exception that is thrown when the tasks array is empty.

Examples

This example demonstrates using ContinueWhenAll() to perform some continuation a set of previously started Tasks has completed.

// C#

// Create and start some tasks

var taskQueue = new Queue<Task>();

for (int i = 0; i < 10; i++)

{

taskQueue.Enqueue(Task.Factory.StartNew(() =>

{

// Do work.

}));

}

// Perform some work with the tasks when they complete.

Task.Factory.ContinueWhenAll(taskQueue.ToArray(), completedTasks =>

{

// Do continuation work.

});

' Visual Basic

' Create and start some tasks

Dim taskQueue As New Queue(Of Task)()

For i As Integer = 0 To 9

taskQueue.Add(Task.Factory.StartNew(Sub()

' Do work.

End Sub))

Next

' Perform some work with the tasks when they complete.

Task.Factory.ContinueWhenAll(taskQueue.ToArray(), Sub(completedTasks)

' Do continuation work.

End Sub)

Version Information

Silverlight

Supported in: 5

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.