Question

i have a question:
I designed my GUI without the InterfaceBuilder,
now i want change the image of a button for a short period of time,
but it won’t change, until the whole for-loop has finished.
What am i doing wrong?

    for (size_t i=0; i< 100; ++i){
      switch (variable) {
        case 0:
          [self changeRedButtonToWhite: redButton];
        break;
        case 1:
        ....
      }
    }

-(IBAction) changeRedButtonToWhite: (id)sender{
    [sender setBackgroundImage: whiteImage forState: UIControlStateNormal];
}

Answer 1

You can’t use a for loop to do this, you should try using an NSTimer instead. The UI isn’t refreshed while there is a loop going on inside the main thread.