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Why does a Control's BeginInvoke() target delegate never occur after Dispose() is called on the Control?


Why does a Control's BeginInvoke() target delegate never occur after Dispose() is called on the Control?

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Why does a Control's BeginInvoke() target delegate never occur after Dispose() is called on the Control?
Tag : chash , By : Ryuken
Date : November 24 2020, 09:00 AM

wish help you to fix your issue As far as I know, BeginInvoke is implemented as a PostMessage, and Dispose will call DestroyWindow on Window Handle Check this answer and the linked MSDN page about DestroyWindow: it say it

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How do I delegate an AsyncCallback method for Control.BeginInvoke? (.NET)


Tag : chash , By : Genipro
Date : March 29 2020, 07:55 AM
To fix this issue Regarding the "Is it possible" part: No, Control.BeginInvoke uses Windows' PostMessage() and that means there is no answer. It also means that the RefreshRulesDelegate is executed on the main thread, not on a background thread.
So, use delegate.BeginInvoke or the ThreadPool and when they are completed use Control.[Begin]Invoke() to update the UI.

Reasons that Control.BeginInvoke would not execute a delegate?


Tag : chash , By : desmiserables
Date : March 29 2020, 07:55 AM
With these it helps According to MSDN InvokeRequired can return false even in cases where InvokeRequired should be true - namely in the case that you access InvokeRequired before the Handle of that control/form (or a parent of it) has been created.
Basically your check is incomplete which leads to the result you see.
if (control.IsHandleCreated)
{
    if (control.InvokeRequired)
    {
        control.BeginInvoke(action);
    }
    else
    {
        action.Invoke();
    }
}
else 
{ 
    // in this case InvokeRequired might lie - you need to make sure that this never happens! 
    throw new Exception ( "Somehow Handle has not yet been created on the UI thread!" );
}

Dispose function of user control not calling from BeginInvoke Method in c# winforms


Tag : chash , By : Brianna
Date : March 29 2020, 07:55 AM
help you fix your problem Assuming that last Dispose() method is for your Form, if your conditional block is not being executed it is because all controls on a Winform are disposed before the Form's Dispose() method is called. This means that components != null is false (because all components are already disposed) and the condition evaluates to false.
Winform Event Lifecycle

Is there a way to cause type inference of the delegate passed to Control.BeginInvoke?


Tag : chash , By : Matt
Date : March 29 2020, 07:55 AM
Hope that helps The issue is that myMethodThatTakesNoParams isn't really a delegate but a so-called "method group" by the compiler. A method group isn't a real type in the CLR. It must be converted to delegate type to be used. When you use a method group like this:
Action a = myMethodThatTakesNoParams;
Action a = new Action(myMethodThatTakesNoParams);
Delegate d = myMethodThatTakesNoParams
static class ControlExtensions
{
    public static IAsyncResult BeginInvoke(this Control c, Action a)
    {
        return c.BeginInvoke(a);
    }
}

Why am I seeing a Cross-thread exception when invoking EventHandler.BeginInvoke through Delegate.Target?


Tag : chash , By : TBG
Date : March 29 2020, 07:55 AM
I hope this helps you . You're calling the delegate on the right thread - but the delegate itself then calls evnt.BeginInvoke, which executes the evnt delegate on the thread pool... so you still end up executing the real underlying delegate (in this case _Test, will set the background colour) on a non-UI thread.
You've already marshaled to the right thread on which to execute the delegate - so just execute it with evnt(sender, e).
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