public static Task Catch<TException>(
	this Task task,
	Predicate<TException> filter,
	Action<Task, TException> handler
)
where TException : Exception

<ExtensionAttribute>
Public Shared Function Catch(Of TException As Exception) ( 
	task As Task,
	filter As Predicate(Of TException),
	handler As Action(Of Task, TException)
) As Task

public:
[ExtensionAttribute]
generic<typename TException>
where TException : Exception
static Task^ Catch(
	Task^ task, 
	Predicate<TException>^ filter, 
	Action<Task^, TException>^ handler
)

[<ExtensionAttribute>]
static member Catch : 
        task : Task * 
        filter : Predicate<'TException> * 
        handler : Action<Task, 'TException> -> Task  when 'TException : Exception

Parameters

task

Type: System.Threading.TasksTask
The antecedent task.

filter

Type: SystemPredicateTException
A predicate defining the condition under which the exception is handled.

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

Usage Note

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

try
{
    await task.ConfigureAwait(false);
}
catch (TException ex) when (filter(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.

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, PredicateTException, FuncTask, TException, Task) instead.

.NET for Windows Store apps

.NET Framework

Portable Class Library

Threading Library

Reference