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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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How do I implement InvokeRequired UI pattern inside an async method?

Let's say I have a Form that tries to deal with a multi-threaded environment; it therefore checks if it's running on the UI thread before any UI modification is done: partial class SomeForm : Form { public void DoSomethingToUserInterface() …
stakx - no longer contributing
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InvokeRequired and BeginInvoke equivalent

I have this function in my Windows Form and now I'm trying to transfer my work to WPF, After transferring I notice that InvokeRequired and BeginInvoke are not supported by WPF. I'm looking for the correct way to translate my function into…
Alexandera MacQueen
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VB - how to access data from a class running on another thread (serial object)

I am writing a class called Field which uses a serial object to get some values from an Arduino. I have an event being raised by the class (when data is received from the serial port, more or less) and when that happens I need to retrieve data from…
Paul Sites
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invokeRequired in silverlight?

Is there in SilverLight something equivalent to Control.InvokeRequired in Winforms? I already found that Winforms Invoke is equivalent to Control.Dispatcher.BeginInvoke but I cant find nothing like InvokeRequired
Wally_the_Walrus
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InvokeRequired keeps returning false when true is expected

I have the following test code. It does nothing useful, but it's there for me to understand VB: Imports System Imports System.IO Imports System.Diagnostics Imports Microsoft.VisualBasic Imports System.Threading Public Class Sandbox Public…
Saaru Lindestøkke
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Finding methods that require InvokeRequired

I come to you to see if someone has an idea on how to solve a problem I've come across while doing a migration to ActiveMQ. I'm using ActiveMQ to send notifications within this project (in C#), and after finishing the implementation i found some…
srodriguez
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C# windows forms custom controls cross-thread operation

I have one main windows form and within that form I have custom controls that represents different screens in application. I want to access this control's child controls. There's something I'm not getting here...sometimes I get this…
user568021
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Why bother with InvokeRequired

I understand the need to use Invoke/BeginInvoke to make calls from worker threads to functions or procedures which make changes to components which belong to the UI thread... My question is - is there a good reason to bother checking InvokeRequired?…
J...
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How to Invoke() when I have no Control available

I'm writing a connection handler (a dialog to request username and password). The code is a handler that shows a dialog. This code could be called from a thread, so I need to Invoke() if InvokeRequired. In a ideal situation I can initialize then…
Daniel Peñalba
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InvokeRequired doubt

The following method will be invoked from a non UI thread. Should I check InvokeRequired, for calling these items in the method? a. this._moduleStatusGrid.Invalidate() b. this.Close() private void CheckIfAllModulesInitComplete() { …
Maanu
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C# cross-thread call problem

I'm writing a form app in c# and I need to be able to change the contents of a Rich Text Box from any thread, I tried using a delegate and InvokeRequired, but the delegate I made still gives me a cross-thread call error, and InvokeRequired crashes…
George Korac
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Non-Invoke-Required path gets hit when updating UI thread control

I have the following Windows Forms code: public partial class Form1 : Form { public Form1() { InitializeComponent(); new Thread(SampleFunction).Start(); } void SampleFunction() { for (int i = 0; i < 10;…
Sabuncu
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Can InvokeIfRequired be used on an entire form before calling the form's method?

In Winforms, I have a non-GUI thread listening for incoming UDP messages. When it receives a message, it update various UI components on a form by calling one of the form's methods. This is apparently a race condition. It seems that I am suppose…
Trevor Hickey
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InvokeRequired is true on PictureBox. How to deal with this?

I had another question on my PictureBox calls giving me 3 kinds of errors, some great answers came in particularly from Conrad Frix. So it led me to figure out where my problem is, but now to fix it I am not 100% sure on. Basically I have a…
Codejoy
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Invoke self to bypass different threads? C#

I have been looking around for about 3 hours and can not get this invoke to work. I need the invoke because whats calling it is in a different thread and says its unstable. Here's what I'm calling (I call it like this textBox1_TextChanged(null,…
Nolan Vannoy
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