TaskFactory.ContinueWhenAll Method (Task, Action(Task), CancellationToken)
Creates a continuation task that starts when a set of specified tasks has completed.
Assembly: mscorlib (in mscorlib.dll)
member ContinueWhenAll : tasks:Task * continuationAction:Action<Task> * cancellationToken:CancellationToken -> Task
- Type: System.Threading.Tasks.Task
The array of tasks from which to continue.
- Type: System.Action(Task)
The action delegate to execute when all tasks in the tasks array have completed.
- Type: System.Threading.CancellationToken
The cancellation token to assign to the new continuation task.
Return ValueType: System.Threading.Tasks.Task
The new continuation task.
An element in the tasks array has been disposed.
The CancellationTokenSource that created cancellationToken has already been disposed.
The tasks array is a null reference (Nothing in Visual Basic).
The continuationAction argument is a null reference (Nothing in Visual Basic).
The tasks array is empty or contains a null value.
The following example creates a cancellation token, which it passes to separate tasks that use a regular expression to count the number of words in a set of text files. The cancellation token is set if a file cannot be found. The ContinueWhenAll method is used to launch a task that displays the total word count when all the antecedent tasks have completed. If the cancellation token is set, which indicates that one or more tasks have been cancelled, it handles the AggregateException exception and displays an error message.