检测用户结束的触摸屏

Question

in my app i'm able to detect a touch by connecting the view to an action touch down event. However, i want to be able to detect that the user lifted his finger off screen. am i able to do that?

Edit: sorry for the short post. actually i have no hint how to do that or even to try to do that!

Answer 1

Well, that depends on where you're trying to track the touch removal. If for example, you're using a button and you've already linked an action to touchDown, you can simply link another action for the buttons control event touch up inside/outside.

If you're interested in tracking that touches ended on the entire screen, you can use -touchesEnded: withEvent: .

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    [super touchesEnded:touches withEvent:event];
}