Question

I have an Windows Form Application, and in it there is a Button. If you click it, then a big loop with massive work is started which might take some time (up to some minutes). In that time, the Window does not react to anything, you cant even move it. Whats the way to go here? Is there a window Update function i could call? Do i have to run the loop in a new thread?

Answer 1

Use multithreading – here is an example I wrote a while back. You basically do all your processing on another thread so it does not tie up the GUI thread.

http://wraithnath.blogspot.com/2010/09/simple-multi-threading-example.html

Start a new Thread on your button click (if you declare the processing thread as a member you can then stop it etc if you want to cancel the process, you can also have a IsProcessing member variable which is checked in the processing loop)

            //Create a new Thread start object passing the method to be started
            ThreadStart oThreadStart = new ThreadStart(this.DoWork);

            //Create a new threat passing the start details
            Thread oThread = new Thread(oThreadStart);

            //Optionally give the Thread a name
            oThread.Name = "Processing Thread";

            //Start the thread
            oThread.Start();

Have a method for the processing

        /// <summary>
        /// Simulate doing work
        /// </summary>
        private void DoWork()
        {
            try
            {
                for (int i = 0; i < m_RecordCount; i++)
                {
                    //Sleep for 100 miliseconds to simulate work
                    Thread.Sleep(100);

                    //increment the progress bar by invoking it on the main window thread
                    progressBar.Invoke(
                        (MethodInvoker)
                        delegate
                        {
                            //Increment the progress bar
                            progressBar.Increment(1);
                        }
                    );
                }

                //Join the thread
                Thread.CurrentThread.Join(0);
            }
            catch (Exception)
            {
                throw;
            }
        }