Question "Start/Stop" Buttons on Form

[mBrannam]

I currently have a working program that creates one colored pixel in a Bitmap, displays the bitmap in a pictureBox, and "jiggles" the pixel by making it move in a random direction by 1 pixel every time a button is clicked.

I want to make the pixel move automatically until a Stop button is pressed.

I have tried

While 1 <> 2
     Pixel.move() 'move the pixel in a random direction
     Me.outputBox.Image = bmp 'update the picturebox
     System.Threads.Thread.Sleep(100) 'wait
End While

for the code in the "Start" button, but the program just hangs indefinitely without updating the pictureBox at all.

Any suggestions?

 

[jmcilhinney]

The program freezes because you are running that loop on the UI thread. You are continually sleeping the UI thread with a tiny bit of work in between, so it never gets a chance to update the UI.

Don't use a loop at all. Add a Timer to your form and set its Interval to 100. Add a Tick event handler and move the PictureBox once and once only in that method. Now you can simply Start and Stop your Timer using your Button.

 

[mBrannam]

Thank you for the fast and informative response. This thread can be marked as solved