Updating a progress bar in a C# GUI from another thread and class [duplicate]

Answer 1

   static main()
    {
         Thread th = new Thread(calling_function);
         th.start();  
    }


    calling_function()
    {
        //do your work;
        MethodInvoker m = new MethodInvoker( ()=> progressbar.Progress=value);
        progressbar.Invoke(m);
    }

Answer 2

.NET Includes a class called the BackgroundWorker, which provides methods for reporting the progress of the background thread in an event. The event is automatically called on the thread which created the BackgroundWorker (typically, the UI thread).

Subscribe to that "ProgressChanged" event, and update the progress bar in that event handler. The official MSDN Documentation provides some sample code.

Answer 3

MethodInvoker mi = new MethodInvoker(() => progressBar.Progress = newProgressValue);
if (progressBar.InvokeRequired)
{
    progressBar.Invoke(mi);
}
else
{
    mi.Invoke();
}

This code belongs in the lengthy task. See:

1. InvokeRequired
2. Invoke
3. Delegates

Lambda is just an over-fancy word for a function (or method) that is declared inline instead of as a method on class or as a raw function in languages that support them. It's "anonymous" if you don't assign it to a named variable. Be careful because they "Capture" the variables needed by them and can behave a bit strangely if you don't understand them.

The syntax for lambdas is pretty easy: () => someValue; is pretty much the same as public void SomeMethod() { return someValue; } put things into the parentheses to add parameters to the lambda. If you only have one parameter, feel free to skip the parentheses.