I am writing a small WPF app which spawns some number of threads to stress test a page of a website. I would like to output some information in the textbox of the wpf form of state of the thread I am manually starting from the main WPF thread. I was kind of expecting the WPF to have the same capabilities as far as synchronizing my threads back to the GUI thread through:
if(this.InvokeRequired)
this.Invoke(ProcessState);
However there is nothing of the sorts in the WPF… what are the options to do the output from a non-gui thread in WPF?
Edit:
The issue now appears to be in the fact that I am not able to check for the method CheckAccess() of the Dispatcher object of my control. I am running the 3.5 version of .net and VS 2008 SP1.
Here is the full metadata of my Dispatcher Class (F12 on it):
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();
}
}
In WPF, this was moved out of the Control/UIElement hierarchy, and into the dispatcher.
The equivelent is Dispatcher.CheckAccess and Dispatcher.Invoke.
You should be able to do:
Your metadata includes:
This is the method you want to use… It doesn’t show up in Intellisense, but it is there, and it does work correctly.