c# - ¿Qué pasó con Control.InvokeRequired en WPF?

.net multithreading

Question

Estoy escribiendo una pequeña aplicación de WPF que genera una cantidad de hilos para realizar pruebas de estrés en una página de un sitio web. Me gustaría mostrar alguna información en el cuadro de texto de la forma wpf del estado del subproceso que estoy iniciando manualmente desde el subproceso principal de WPF. Esperaba que el WPF tuviera las mismas capacidades en cuanto a la sincronización de mis hilos con el hilo de la GUI a través de:

  if(this.InvokeRequired)
       this.Invoke(ProcessState);

Sin embargo, no hay nada de eso en el WPF ... ¿cuáles son las opciones para hacer la salida de un subproceso que no es de GUI en WPF?

Edición: el problema ahora parece estar en el hecho de que no puedo verificar el método CheckAccess() del objeto Dispatcher de mi control. Estoy ejecutando la versión 3.5 de .net y VS 2008 SP1.

Aquí están los metadatos completos de mi clase Dispatcher (F12 en él):

  using MS.Internal.WindowsBase;
  using System;
  using System.ComponentModel;
  using System.Security;
  using System.Threading;

  namespace System.Windows.Threading
  {
     // Summary:
//     Provides services for managing the queue of work items for a thread.
public sealed class Dispatcher
{
    // Summary:
    //     Gets the System.Windows.Threading.Dispatcher for the thread currently executing
    //     and creates a new System.Windows.Threading.Dispatcher if one is not already
    //     associated with the thread.
    //
    // Returns:
    //     The dispatcher associated with the current thread.
    public static Dispatcher CurrentDispatcher { get; }
    //
    // Summary:
    //     Determines whether the System.Windows.Threading.Dispatcher has finished shutting
    //     down.
    //
    // Returns:
    //     true if the dispatcher has finished shutting down; otherwise, false.
    public bool HasShutdownFinished { get; }
    //
    // Summary:
    //     Determines whether the System.Windows.Threading.Dispatcher is shutting down.
    //
    // Returns:
    //     true if the System.Windows.Threading.Dispatcher has started shutting down;
    //     otherwise, false.
    public bool HasShutdownStarted { get; }
    //
    // Summary:
    //     Gets the collection of hooks that provide additional event information about
    //     the System.Windows.Threading.Dispatcher.
    //
    // Returns:
    //     The hooks associated with this System.Windows.Threading.Dispatcher.
    [EditorBrowsable(EditorBrowsableState.Advanced)]
    public DispatcherHooks Hooks { get; }
    //
    // Summary:
    //     Gets the thread this System.Windows.Threading.Dispatcher is associated with.
    //
    // Returns:
    //     The thread.
    public Thread Thread { get; }

    // Summary:
    //     Occurs when the System.Windows.Threading.Dispatcher finishes shutting down.
    public event EventHandler ShutdownFinished;
    //
    // Summary:
    //     Occurs when the System.Windows.Threading.Dispatcher begins to shut down.
    public event EventHandler ShutdownStarted;
    //
    // Summary:
    //     Occurs when a thread exception is thrown and uncaught during execution of
    //     a delegate by way of Overload:System.Windows.Threading.Dispatcher.Invoke
    //     or Overload:System.Windows.Threading.Dispatcher.BeginInvoke.
    public event DispatcherUnhandledExceptionEventHandler UnhandledException;
    //
    // Summary:
    //     Occurs when a thread exception is thrown and uncaught during execution of
    //     a delegate by way of Overload:System.Windows.Threading.Dispatcher.Invoke
    //     or Overload:System.Windows.Threading.Dispatcher.BeginInvoke when in the filter
    //     stage.
    public event DispatcherUnhandledExceptionFilterEventHandler UnhandledExceptionFilter;

    public DispatcherOperation BeginInvoke(Delegate method, params object[] args);
    //
    // Summary:
    //     Executes the specified delegate asynchronously at the specified priority
    //     on the thread the System.Windows.Threading.Dispatcher is associated with.
    //
    // Parameters:
    //   priority:
    //     The priority, relative to the other pending operations in the System.Windows.Threading.Dispatcher
    //     event queue, the specified method is invoked.
    //
    //   method:
    //     The delegate to a method that takes no arguments, which is pushed onto the
    //     System.Windows.Threading.Dispatcher event queue.
    //
    // Returns:
    //     An object, which is returned immediately after Overload:System.Windows.Threading.Dispatcher.BeginInvoke
    //     is called, that can be used to interact with the delegate as it is pending
    //     execution in the event queue.
    //
    // Exceptions:
    //   System.ArgumentNullException:
    //     method is null.
    //
    //   System.ComponentModel.InvalidEnumArgumentException:
    //     priority is not a valid System.Windows.Threading.DispatcherPriority.
    [EditorBrowsable(EditorBrowsableState.Never)]
    [Browsable(false)]
    public DispatcherOperation BeginInvoke(DispatcherPriority priority, Delegate method);
    public DispatcherOperation BeginInvoke(Delegate method, DispatcherPriority priority, params object[] args);
    //
    // Summary:
    //     Executes the specified delegate asynchronously at the specified priority
    //     and with the specified argument on the thread the System.Windows.Threading.Dispatcher
    //     is associated with.
    //
    // Parameters:
    //   priority:
    //     The priority, relative to the other pending operations in the System.Windows.Threading.Dispatcher
    //     event queue, the specified method is invoked.
    //
    //   method:
    //     A delegate to a method that takes one argument, which is pushed onto the
    //     System.Windows.Threading.Dispatcher event queue.
    //
    //   arg:
    //     The object to pass as an argument to the specified method.
    //
    // Returns:
    //     An object, which is returned immediately after Overload:System.Windows.Threading.Dispatcher.BeginInvoke
    //     is called, that can be used to interact with the delegate as it is pending
    //     execution in the event queue.
    //
    // Exceptions:
    //   System.ArgumentNullException:
    //     method is null.
    //
    //   System.ComponentModel.InvalidEnumArgumentException:
    //     priority is not a valid System.Windows.Threading.DispatcherPriority.
    [EditorBrowsable(EditorBrowsableState.Never)]
    [Browsable(false)]
    public DispatcherOperation BeginInvoke(DispatcherPriority priority, Delegate method, object arg);
    //
    // Summary:
    //     Executes the specified delegate asynchronously at the specified priority
    //     and with the specified array of arguments on the thread the System.Windows.Threading.Dispatcher
    //     is associated with.
    //
    // Parameters:
    //   priority:
    //     The priority, relative to the other pending operations in the System.Windows.Threading.Dispatcher
    //     event queue, the specified method is invoked.
    //
    //   method:
    //     A delegate to a method that takes multiple arguments, which is pushed onto
    //     the System.Windows.Threading.Dispatcher event queue.
    //
    //   arg:
    //     The object to pass as an argument to the specified method.
    //
    //   args:
    //     An array of objects to pass as arguments to the specified method.
    //
    // Returns:
    //     An object, which is returned immediately after Overload:System.Windows.Threading.Dispatcher.BeginInvoke
    //     is called, that can be used to interact with the delegate as it is pending
    //     execution in the System.Windows.Threading.Dispatcher queue.
    //
    // Exceptions:
    //   System.ArgumentNullException:
    //     method is null.
    //
    //   System.ComponentModel.InvalidEnumArgumentException:
    //     System.Windows.Threading.DispatcherPriority is not a valid priority.
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public DispatcherOperation BeginInvoke(DispatcherPriority priority, Delegate method, object arg, params object[] args);
    //
    // Summary:
    //     Initiates shutdown of the System.Windows.Threading.Dispatcher asynchronously.
    //
    // Parameters:
    //   priority:
    //     The priority at which to begin shutting down the dispatcher.
    [SecurityCritical]
    public void BeginInvokeShutdown(DispatcherPriority priority);
    //
    // Summary:
    //     Determines whether the calling thread is the thread associated with this
    //     System.Windows.Threading.Dispatcher.
    //
    // Returns:
    //     true if the calling thread is the thread associated with this System.Windows.Threading.Dispatcher;
    //     otherwise, false.
    [EditorBrowsable(EditorBrowsableState.Never)]
    public bool CheckAccess();
    //
    // Summary:
    //     Disables processing of the System.Windows.Threading.Dispatcher queue.
    //
    // Returns:
    //     A structure used to re-enable dispatcher processing.
    public DispatcherProcessingDisabled DisableProcessing();
    //
    // Summary:
    //     Requests that all frames exit, including nested frames.
    [SecurityCritical]
    public static void ExitAllFrames();
    //
    // Summary:
    //     Gets the System.Windows.Threading.Dispatcher for the specified thread.
    //
    // Parameters:
    //   thread:
    //     The thread to obtain the System.Windows.Threading.Dispatcher from.
    //
    // Returns:
    //     The dispatcher for thread.
    public static Dispatcher FromThread(Thread thread);
    public object Invoke(Delegate method, params object[] args);
    //
    // Summary:
    //     Executes the specified delegate synchronously at the specified priority on
    //     the thread on which the System.Windows.Threading.Dispatcher is associated
    //     with.
    //
    // Parameters:
    //   priority:
    //     The priority, relative to the other pending operations in the System.Windows.Threading.Dispatcher
    //     event queue, the specified method is invoked.
    //
    //   method:
    //     A delegate to a method that takes no arguments, which is pushed onto the
    //     System.Windows.Threading.Dispatcher event queue.
    //
    // Returns:
    //     The return value from the delegate being invoked or null if the delegate
    //     has no return value.
    //
    // Exceptions:
    //   System.ArgumentException:
    //     priority is equal to System.Windows.Threading.DispatcherPriority.Inactive.
    //
    //   System.ComponentModel.InvalidEnumArgumentException:
    //     priority is not a valid priority.
    //
    //   System.ArgumentNullException:
    //     method is null.
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public object Invoke(DispatcherPriority priority, Delegate method);
    public object Invoke(Delegate method, DispatcherPriority priority, params object[] args);
    public object Invoke(Delegate method, TimeSpan timeout, params object[] args);
    //
    // Summary:
    //     Executes the specified delegate at the specified priority with the specified
    //     argument synchronously on the thread the System.Windows.Threading.Dispatcher
    //     is associated with.
    //
    // Parameters:
    //   priority:
    //     The priority, relative to the other pending operations in the System.Windows.Threading.Dispatcher
    //     event queue, the specified method is invoked.
    //
    //   method:
    //     A delegate to a method that takes one argument, which is pushed onto the
    //     System.Windows.Threading.Dispatcher event queue.
    //
    //   arg:
    //     An object to pass as an argument to the given method.
    //
    // Returns:
    //     The return value from the delegate being invoked or null if the delegate
    //     has no return value.
    //
    // Exceptions:
    //   System.ArgumentException:
    //     priority is equal to System.Windows.Threading.DispatcherPriority.Inactive.
    //
    //   System.ComponentModel.InvalidEnumArgumentException:
    //     priority is not a valid priority.
    //
    //   System.ArgumentNullException:
    //     method is null.
    [EditorBrowsable(EditorBrowsableState.Never)]
    [Browsable(false)]
    public object Invoke(DispatcherPriority priority, Delegate method, object arg);
    //
    // Summary:
    //     Executes the specified delegate synchronously at the specified priority and
    //     with the specified time-out value on the thread the System.Windows.Threading.Dispatcher
    //     was created.
    //
    // Parameters:
    //   priority:
    //     The priority, relative to the other pending operations in the System.Windows.Threading.Dispatcher
    //     event queue, the specified method is invoked.
    //
    //   timeout:
    //     The maximum time to wait for the operation to finish.
    //
    //   method:
    //     The delegate to a method that takes no arguments, which is pushed onto the
    //     System.Windows.Threading.Dispatcher event queue.
    //
    // Returns:
    //     The return value from the delegate being invoked or null if the delegate
    //     has no return value.
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public object Invoke(DispatcherPriority priority, TimeSpan timeout, Delegate method);
    public object Invoke(Delegate method, TimeSpan timeout, DispatcherPriority priority, params object[] args);
    //
    // Summary:
    //     Executes the specified delegate at the specified priority with the specified
    //     arguments synchronously on the thread the System.Windows.Threading.Dispatcher
    //     is associated with.
    //
    // Parameters:
    //   priority:
    //     The priority, relative to the other pending operations in the System.Windows.Threading.Dispatcher
    //     event queue, the specified method is invoked.
    //
    //   method:
    //     A delegate to a method that takes multiple arguments, which is pushed onto
    //     the System.Windows.Threading.Dispatcher event queue.
    //
    //   arg:
    //     An object to pass as an argument to the given method.
    //
    //   args:
    //     An array of objects to pass as arguments to the given method.
    //
    // Returns:
    //     The return value from the delegate being invoked or null if the delegate
    //     has no return value.
    //
    // Exceptions:
    //   System.ArgumentException:
    //     priority is equal to System.Windows.Threading.DispatcherPriority.Inactive.
    //
    //   System.ComponentModel.InvalidEnumArgumentException:
    //     priority is not a valid priority.
    //
    //   System.ArgumentNullException:
    //     method is null.
    [EditorBrowsable(EditorBrowsableState.Never)]
    [Browsable(false)]
    public object Invoke(DispatcherPriority priority, Delegate method, object arg, params object[] args);
    //
    // Summary:
    //     Executes the specified delegate at the specified priority with the specified
    //     argument synchronously on the thread the System.Windows.Threading.Dispatcher
    //     is associated with.
    //
    // Parameters:
    //   priority:
    //     The priority, relative to the other pending operations in the System.Windows.Threading.Dispatcher
    //     event queue, the specified method is invoked.
    //
    //   timeout:
    //     The maximum time to wait for the operation to finish.
    //
    //   method:
    //     A delegate to a method that takes multiple arguments, which is pushed onto
    //     the System.Windows.Threading.Dispatcher event queue.
    //
    //   arg:
    //     An object to pass as an argument to the given method. This can be null if
    //     no arguments are needed.
    //
    // Returns:
    //     The return value from the delegate being invoked or null if the delegate
    //     has no return value.
    //
    // Exceptions:
    //   System.ArgumentException:
    //     priority is equal to System.Windows.Threading.DispatcherPriority.Inactive.
    //
    //   System.ComponentModel.InvalidEnumArgumentException:
    //     priority is not a valid priority.
    //
    //   System.ArgumentNullException:
    //     method is null.
    [EditorBrowsable(EditorBrowsableState.Never)]
    [Browsable(false)]
    public object Invoke(DispatcherPriority priority, TimeSpan timeout, Delegate method, object arg);
    //
    // Summary:
    //     Executes the specified delegate at the specified priority with the specified
    //     arguments synchronously on the thread the System.Windows.Threading.Dispatcher
    //     is associated with.
    //
    // Parameters:
    //   priority:
    //     The priority, relative to the other pending operations in the System.Windows.Threading.Dispatcher
    //     event queue, the specified method is invoked.
    //
    //   timeout:
    //     The maximum time to wait for the operation to finish.
    //
    //   method:
    //     A delegate to a method that takes multiple arguments, which is pushed onto
    //     the System.Windows.Threading.Dispatcher event queue.
    //
    //   arg:
    //     An object to pass as an argument to the specified method.
    //
    //   args:
    //     An array of objects to pass as arguments to the specified method.
    //
    // Returns:
    //     The return value from the delegate being invoked or null if the delegate
    //     has no return value.
    //
    // Exceptions:
    //   System.ArgumentException:
    //     priority is equal to System.Windows.Threading.DispatcherPriority.Inactive.
    //
    //   System.ComponentModel.InvalidEnumArgumentException:
    //     priority is not a valid System.Windows.Threading.DispatcherPriority.
    //
    //   System.ArgumentNullException:
    //     method is null.
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public object Invoke(DispatcherPriority priority, TimeSpan timeout, Delegate method, object arg, params object[] args);
    //
    // Summary:
    //     Initiates the shutdown process of the System.Windows.Threading.Dispatcher
    //     synchronously.
    [SecurityCritical]
    public void InvokeShutdown();
    //
    // Summary:
    //     Enters an execute loop.
    //
    // Parameters:
    //   frame:
    //     The frame for the dispatcher to process.
    //
    // Exceptions:
    //   System.ArgumentNullException:
    //     frame is null.
    //
    //   System.InvalidOperationException:
    //     System.Windows.Threading.Dispatcher.HasShutdownFinished is true -or- frame
    //     is running on a different System.Windows.Threading.Dispatcher.  -or- Dispatcher
    //     processing has been disabled.
    [SecurityCritical]
    public static void PushFrame(DispatcherFrame frame);
    //
    // Summary:
    //     Pushes the main execution frame on the event queue of the System.Windows.Threading.Dispatcher.
    [SecurityCritical]
    public static void Run();
    //
    // Summary:
    //     Determines whether the specified System.Windows.Threading.DispatcherPriority
    //     is a valid priority.
    //
    // Parameters:
    //   priority:
    //     The priority to check.
    //
    //   parameterName:
    //     A string that will be returned by the exception that occurs if the priority
    //     is invalid.
    //
    // Exceptions:
    //   System.ComponentModel.InvalidEnumArgumentException:
    //     priority is not a valid System.Windows.Threading.DispatcherPriority.
    public static void ValidatePriority(DispatcherPriority priority, string parameterName);
    //
    // Summary:
    //     Determines whether the calling thread has access to this System.Windows.Threading.Dispatcher.
    //
    // Exceptions:
    //   System.InvalidOperationException:
    //     The calling thread does not have access to this System.Windows.Threading.Dispatcher.
    [EditorBrowsable(EditorBrowsableState.Never)]
    public void VerifyAccess();
}

}

Answer 1

En WPF, esto fue movido fuera de la jerarquía de Control / UIElement, y hacia el despachador.

El equivalente es Dispatcher.CheckAccess y Dispatcher.Invoke .

Deberías poder hacer:

if (someControl.Dispatcher.CheckAccess())
      UpdateUI();
else
    someControl.Dispatcher.Invoke(new Action(UpdateUI));

Sus metadatos incluyen:

//
// Summary:
//     Determines whether the calling thread is the thread associated with this
//     System.Windows.Threading.Dispatcher.
//
// Returns:
//     true if the calling thread is the thread associated with this System.Windows.Threading.Dispatcher;
//     otherwise, false.
[EditorBrowsable(EditorBrowsableState.Never)]
public bool CheckAccess();

Este es el método que desea utilizar ... No aparece en Intellisense, pero está ahí y funciona correctamente.

Answer 2

Para mí eso funcionó en cada página, UserControl y Frame.

  Implements IDisposable ''Code is implemented automatically
  Public Sub New()

        '' This call is required by the designer.
        InitializeComponent()

        '' Add any initialization after the InitializeComponent() call.
        AddHandler Me.Dispatcher.ShutdownStarted, AddressOf Me_HasShutDownStarted

    End Sub


    Private Sub Me_HasShutDownStarted(ByVal sender As Object, ByVal e As System.EventArgs)
        If Me.disposedValue = False Then Call Me.Dispose()
    End Sub

Answer 3

Si solo está convirtiendo WinForm Invoke a WPF Dispatch, solo se necesitan algunos pequeños cambios para convertir su código de WinForm en el código de WPF. Esto funcionó para mi control llamado "_connection", y se reescribió para trabajar en una aplicación WPF.

// ---- Original WinForm code ----
delegate void SetIndicatorCallback(bool bVal);

private void SetIndicator(bool bVal)
{
   if (this._connection.InvokeRequired)
   {
      SetIndicatorCallback d = new SetIndicatorCallback(SetIndicator);
      this.Invoke(d, new object[] { bVal });
   }
   else
   {
      if (bVal)
      {
           // Change the control''s color, or whatever action is required.
      }

   }
}

// ---- WPF ----

// Still using a delegate 
delegate void SetIndicatorCallback(bool bVal);


private void SetIndicator(bool bVal)
    {
        if (this._connection.Dispatcher.CheckAccess())
        {
          if (bVal)
          {
                // Change the control'' color, or whatever action is needed.
          }
        }
        else
        { 
           SetIndicatorCallback d = new SetIndicatorCallback(SetIndicator);
           this.Dispatcher.BeginInvoke(d, new object[] { bVal });
        }
     }