The method.Invoke() call executes the delegate on the current executing thread. Using the BeginInvoke(method) ensures that the delegate is called on the GUI thread. This is the correct way of avoiding code duplication when the same method can be called both from the GUI thread and other threads.
You have to specify which method you want: class SomeType { void Foo(int size, string bar) { } void Foo() { } } SomeType obj = new SomeType(); // call with int and string arguments obj.GetType() .GetMethod(“Foo”, new Type[] { typeof(int), typeof(string) }) .Invoke(obj, new object[] { 42, “Hello” }); // call without arguments obj.GetType() … Read more
Going over each of your questions, one by one: Not quite; you should only invoke onto the UI thread when necessary. See #2. Yes, it does matter. You should not just automatically Invoke everything. The key is to only invoke onto the UI thread if necessary. To do this, you can use the Dispatcher.CheckAccess method. … Read more
What you have here is a race condition. You’re better off just catching the ObjectDisposed exception and be done with it. In fact, I think in this case it is the only working solution. try { if (mImageListView.InvokeRequired) mImageListView.Invoke(new YourDelegate(thisMethod)); else mImageListView.RefreshInternal(); } catch (ObjectDisposedException ex) { // Do something clever }
EDIT: As I understand your issue, the problem is purely an IDE one; you don’t like VS treating the exception thrown by the invocation of the MethodInfo as uncaught, when it clearly isn’t. You can read about how to resolve this problem here: Why is TargetInvocationException treated as uncaught by the IDE? It appears to … Read more
From non-UI threads we can’t touch the UI – very bad things can happen, since controls have thread affinity. So from a non-UI thread we must (at a minumum) call Invoke or BeginInvoke. For UI-threads, however – we don’t want to call Invoke lots of time; the issue is that if you are already on … Read more
When you use Dispatcher.BeginInvoke it means that it schedules the given action for execution in the UI thread at a later point in time, and then returns control to allow the current thread to continue executing. Invoke blocks the caller until the scheduled action finishes. When you use BeginInvoke your loop is going to run … Read more
Did you try MSDN Control.Invoke I just wrote a little WinForm application to demonstrate Control.Invoke. When the form is created, Start some work on background thread. After that work is done, Update the status in a label. public Form1() { InitializeComponent(); //Do some work on a new thread Thread backgroundThread = new Thread(BackgroundWork); backgroundThread.Start(); } … Read more
You should create Begin and End extension methods as well. And if you use generics, you can make the call look a little nicer. public static class ControlExtensions { public static void InvokeEx<T>(this T @this, Action<T> action) where T : Control { if (@this.InvokeRequired) { @this.Invoke(action, new object[] { @this }); } else { if … Read more
Your app has a main UI thread (usually ManagedThreadId==1). Typically in a chat app your events will come in on other threads (either dedicated socket listen threads or thread pool threads from listening code). If you want to update the UI from an event that gets pull on some other thread you must use the … Read more