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Avoiding InvokeRequired

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27 Apr 2012CPOL 23.7K   6   5
This is an alternative for "C# Pivot Table"

Introduction

This minor article is an enhancement to the excellent piece of work by Pablo Grisafi.  The goal is to enhance Pablo's code to work in cases where controls are not all created on the same (usually "UI") thread. 

Using the code  

The enhancement is relatively minor and virtually everyone with enough understanding of delegates and generics could easily enhance Pablo's version as I did below.  While Pablo's version works for 95+% cases, in very special circumstances, a control might need to be created on another thread, thus requiring InvokeRequired check on that control's property -- not on the form's.  The idea behind these enhancements is to allow the extension method to handle this type of scenario.  

The code below helps ensure that all controls are updated on the thread on which they were created even when they were created on different threads.  

C#
static class ControlExtensions
{
  public static void InvokeOnOwnerThread<T>(this T control, Action<T> invoker) where T : Control
  {
    if (control.InvokeRequired)
      control.Invoke(invoker, control);
    else
      invoker(control);
  }
}  

The code that uses this extension method would look like this: 

C#
private void UpdateFormTextFromSomeThread(string message)
{
  this.InvokeOnOwnerThread((form) => form.Text = message);  
}

History

No changes. 

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer (Senior) Credit Suisse
United States United States
I was introduced to computer programming at the age of 12 although I did not become particularly interested in software development until I turned 19 when I used one of my electives to take a computer science class. Since then, I never stopped writing software. My current interests are .NET, patterns and practices, and agile development (TDD and BDD).

Comments and Discussions

 
QuestionConverting it to vb.net Pin
pilouk4-Oct-12 4:56
pilouk4-Oct-12 4:56 
AnswerRe: Converting it to vb.net Pin
Igor Pashchuk, MBA12-Oct-12 13:04
Igor Pashchuk, MBA12-Oct-12 13:04 
AnswerRe: Converting it to vb.net Pin
sage4530-Nov-12 6:33
sage4530-Nov-12 6:33 
SuggestionInstantiating UI objects on a non-UI thread Pin
EricWRichardson1-Jun-12 10:09
EricWRichardson1-Jun-12 10:09 
GeneralRe: Instantiating UI objects on a non-UI thread Pin
Igor Pashchuk, MBA1-Jun-12 16:30
Igor Pashchuk, MBA1-Jun-12 16:30 

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