QueueUserWorkItem Método (WaitCallback)
Este artículo proviene de un motor de traducción automática. Mueva el puntero sobre las frases del artículo para ver el texto original. Más información.

ThreadPool::QueueUserWorkItem (Método) (WaitCallback^)


Pone en cola un método para su ejecución.El método se ejecuta cuando hay disponible un subproceso de grupo de subprocesos.

Espacio de nombres:   System.Threading
Ensamblado:  mscorlib (en mscorlib.dll)

static bool QueueUserWorkItem(
	WaitCallback^ callBack



WaitCallback que representa el método que se va a ejecutar.

Valor devuelto

Type: System::Boolean

true si el método se pone en la cola correctamente; se produce la excepción NotSupportedException si el elemento de trabajo no se puede poner en la cola.

Exception Condition

callBack is null.


The common language runtime (CLR) is hosted, and the host does not support this action.

You can place data required by the queued method in the instance fields of the class in which the method is defined, or you can use the QueueUserWorkItem(WaitCallback^, Object^) overload that accepts an object containing the necessary data.


Visual Basic users can omit the WaitCallback constructor, and simply use the AddressOf operator when passing the callback method to QueueUserWorkItem.Visual Basic automatically calls the correct delegate constructor.

In the .NET Framework version 2.0, the Thread::CurrentPrincipal property value is propagated to worker threads queued using the QueueUserWorkItem method.In earlier versions, the principal information is not propagated.

The following example uses the QueueUserWorkItem(WaitCallback) method overload to queue a task, which is represented by the ThreadProc method, to execute when a thread becomes available.No task information is supplied with this overload.Therefore, the information that is available to the ThreadProc method is limited to the object the method belongs to.

using namespace System;
using namespace System::Threading;
ref class Example

   // This thread procedure performs the task.
   static void ThreadProc( Object^ stateInfo )

      // No state object was passed to QueueUserWorkItem, so 
      // stateInfo is 0.
      Console::WriteLine( "Hello from the thread pool." );


int main()

   // Queue the task.
   ThreadPool::QueueUserWorkItem( gcnew WaitCallback( Example::ThreadProc ) );
   Console::WriteLine( "Main thread does some work, then sleeps." );

   // If you comment out the Sleep, the main thread exits before
   // the thread pool task runs.  The thread pool uses background
   // threads, which do not keep the application running.  (This
   // is a simple example of a race condition.)
   Thread::Sleep( 1000 );
   Console::WriteLine( "Main thread exits." );
   return 0;
// The example displays output like the following:
//       Main thread does some work, then sleeps.
//       Hello from the thread pool.
//       Main thread exits.

.NET Framework
Disponible desde 1.1
Portable Class Library
Compatible con: portable .NET platforms
Disponible desde 2.0
Windows Phone Silverlight
Disponible desde 7.0
Volver al principio
© 2015 Microsoft