[C#] Program Not Responding

Question

Ok hi, I am making a program in Microsoft Visual Studio and every time I run it and and click start (I have a start button), it will do what I have it programmed to do, but the form always freezes and doesn't display what i want it too (it says "Not Responding" once i start it). It is good for doing it job, but I have things on the form that are supposed to be shown. While it keeps freezing, it does not give me the option to stop it, or show any labels I have set to change, during it's running. Any help on this will be appreciated. Thank You.

EDIT: This is what I have:

        void CheckAll()
    {
        for (; ; )
        {
            CheckPixel();
            Application.DoEvents();
        }
    }

It is constantly doing CheckPixel();, I take it that is the reason why it is freezing. There are never any breaks.

Answer 1

Put your program in a try-catch block and then have any exception thrown print in a messagebox. http://msdn.microsoft.com/en-us/library/0yd65esw%28VS.80%29.aspx

Also, try inserting a breakpoint at the point of click to identify where exactly it freezes up.

Answer 2

This usually means you are blocking the UI thread (e.g. running a long operation inside a button click handler). Instead of using the UI thread, you will generally need to offload long I/O operations to the ThreadPool or your own worker threads. This is not always easy to do and requires careful design and a good understanding of concurrency, etc.

Answer 3

Your application is freezing because it's in an infinite loop. I don't know how you can fix it, because I don't know exactly what you're trying to do here.

Update: since I need to go to bed, I'm going to toss out a total guess here. Your CheckPixel() method should probably have a signature like this:

public bool CheckPixel(int x, int y)
{
    Color color = _myBitmap.GetPixel(x, y);
    return (color == Color.Red);
}

where _myBitmap is a form-scoped Bitmap. Then your CheckAll() method should be something like this:

public bool CheckAll()
{
    for (int x = 0; x < _myBitmap.Width; x++)
    {
        for (int y = 0; y < _myBitmap.Height; y++)
        {
            if (CheckPixel(x, y))
            {
                return true;
            }
        }
    }
    return false;
}

G'night folks! I'll be here all week.

Answer 4

Instead of Application.DoEvents() why don't you replace with Threading.Thread.Sleep(0)? I'm not an expert but I prefer Thread.Sleep better then DoEvents.

Answer 5

You need to have some way of exiting out of the loop.

Either your for loop needs the logic to go from ? to ? (as in

for(int i = 0; , < 100; 1++)

which will will loop 100 times

OR

for(;;)
{
   if(SomeCondition == true)
   {
      break;
   }
}