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CoreTaskExtensionsCatchTException Method (Task, ActionTask, TException)
Synchronously execute an exception handling continuation when a task completes in the Canceled or Faulted state. If the antecedent task completes successfully, or if the Exception it provides is not a TException wrapped in an AggregateException, the status of the antecedent is directly applied to the task returned by this method. Otherwise, the status of the cleanup operation is directly applied to the task returned by this method.

Namespace: Rackspace.Threading
Assembly: Rackspace.Threading (in Rackspace.Threading.dll) Version: 2.1.0-beta1
Syntax
public static Task Catch<TException>(
	this Task task,
	Action<Task, TException> handler
)
where TException : Exception

Parameters

task
Type: System.Threading.TasksTask
The antecedent task.
handler
Type: SystemActionTask, TException
The exception handler continuation action to execute when task completes with an exception of type TException.

Type Parameters

TException
The type of exception which is handled by handler.

Return Value

Type: Task
A Task representing the asynchronous operation.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type Task. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).
Exceptions
ExceptionCondition
ArgumentNullException

If task is .

-or-

If handler is .

Remarks

This code implements support for the following construct without requiring the use of /.

C#
try
{
    await task.ConfigureAwait(false);
}
catch (TException ex)
{
    handler(task, ex);
}

This method is capable of handling Canceled antecedent tasks when TException is assignable from TaskCanceledException.

This method ensures that exception information provided by a faulted or canceled task is not wrapped in an additional AggregateException.

Note Notes to Callers

Since the continuation is executed synchronously, this method should only be used for lightweight exception handler methods. For non-trivial exception handlers, use a Task for the exception handling operation and call CatchTException(Task, FuncTask, TException, Task) instead.

Version Information

.NET for Windows Store apps

Supported in: Windows 8

.NET Framework

Supported in: 4.5, 4.0, 3.5

Portable Class Library

Supported in: Portable Class Library (Legacy), Portable Class Library

Threading Library

Supported in: 2.1, 2.0, 1.1
See Also