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Questions tagged [invokerequired]

InvokeRequired refers to the .NET WinForms Control.InvokeRequired method, which needs to be checked before UI updates are made.

In .NET WinForms Control.InvokeRequired needs to be checked before UI updates are made.

It will be True when the handle has been created and the current thread is not the thread on which the control was created.

When it is True, you need to perform the UI update using a delegate call through Control.Invoke which will marshal the delegate onto the UI thread.

MSDN link - Note that other frameworks can implement this concept using the System.ComponentModel.ISynchronizeInvoke interface (though something is still needed to actually marshal the calls back to another thread).

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thread Invocation in C# .WPF

there. I'm using C# .wpf, and I get this some code from C# source, but I can't use it. is there anything that I must change? or do? // Delegates to enable async calls for setting controls properties private delegate void…
Reza
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Method executing twice after being invoked

I'm having a "invoke" issue that I can't resolve. I'll try to be as thorough in my description as possible, but I'm new to this so bear with me and let me know if you need more information. I've got a background thread running that when prompted…
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What is wrong with my InvokeRequied #2?

The first topic is What wrong with my InvokeRequied I followed the answer that he recommended it to me but I found a new problem. The result of below picture is cross thread exception. What is wrong with my code ? How to solve this problem ?
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Multi-threading, access UI control

I have a simple app with the usual UI thread and a background worker, in the background worker I need to dynamically create LinkLabels and place them in a FlowLayoutPanel. In order to do this I need to set the parent of the LinkLabel to the…
Hammy
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When does the vaIue of the InvokeRequired property change?

When i want to use delegate class to make call while windows form working, i always have to use InvokeRequired. It is ok. But who changed the InvokeReuqired property while it is working. Please check this image:
uzay95
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Is always using Form.Invoke() a bad practice?

I know, this may be a very easy question yet I couldn't be sure. I have this in a module: Public theHandle As IntPtr And this in my main form named Form1: Private Sub Form1_HandleCreated(sender As Object, e As System.EventArgs) Handles…
gunakkoc
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Multithreading for a progressbar and code locations (vb.net)?

I am stuck updating a progressbar from a different thread. I did get it running in the simplest way, but then cleaning the code gets me stuck. My testing code looks like all the examples on the web related to backgroundworker and BeginInvoke. FormP…
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Accessing WebBrowsers From Threadpool

I'm trying to access information on a web browser from another thread. When trying to access the browser.DocumentTitle, I get this error: The name DocumentTitle does not exist in the current context I can successfully navigate to webpages inside the…
user1642357
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Why aren't there built-in "Safe" methods for UI interaction?

I am an enthusiast developer rather than a professional one, and as such I don't have a highly technical understanding of why some issues are as they are. Recently, I've been working on applications where I've been trying to improve responsiveness…
ainwood
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C# InvokeRequired with property getter

I would like to make my getter thread safe. When I do this, I get an error: public ApplicationViewModel SelectedApplication { get { if (InvokeRequired) { …
John
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InvokeRequired hangs

The UI thread hangs occasionally at the statement 'if (this.InvokeRequired)' in the following method. Can you help me to identify the cause of the issue public void OnModuleInitializationCompleted(object sender, EventArgs e) { …
Maanu
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Why Form.Close wait MessageBox.Show?

look this please: var form = new Form(); form.Shown += (_, __) => { var timer = new System.Windows.Forms.Timer { Interval = 1000 }; timer.Tick += (x, xx) => { timer.Stop(); GC.KeepAlive(timer); …
ahdung
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VB.net Invoke a property change in a control

Lots of examples of how to invoke methods, but how does one change a simple property? For demonstration-sake, here's a very simple set of code that should help. Let's say I need to set the visible property from a child form, and thus, it needs to…
Brad
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Threading: Invoke gets stuck .NET

I have a system tray application. The tray application has an icon and a context menu with some options. There is a menu called status which contains below toolstripmenuitems: Start Restart Stop They are enabled/disabled according to some…
Willy
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How can I call the .Invoke method of a Delegate.Target?

Given the following method : public static void ExecuteAsync( this EventHandler eH, object sender, EventArgs eA ) { eH.GetInvocationList( ).Cast( ).ToList( ).ForEach( e => { e.BeginInvoke( sender, eA, IAR => …
Will
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