IPhone touchesEnded sometimes not called

Question

I have a small game that needs to know when a user touches the screen and also when they release.
Now whilst I always get a touchesBegan event, sometimes I don't get the corresponding touchesEnded event (which is somewhat annoying).
Was just wondering if anyone else had seen this.

Answer 1

Hi, I've been wrestling with this problem for a few days now. I have something of a fix, which may help some of you, but it requires turning on the accelerometer.
First, it does seems as if the problem is that the timer events are crowding out touches and accelerometer events. But I've found a way to use the accelerometer update to avoid the problem.
Here is my workaround:
1. turn on the UIAccelerometer in your initialization code:
UIAccelerometer* theAccelerometer = [UIAccelerometer sharedAccelerometer];
theAccelerometer.delegate = self;
2. set the UIAccelerometer update interval to your desired frame rate:
theAccelerometer.updateInterval = .01667f;// ie, 60 fps
(For some reason — I am new to C — 1/60 doesn't seem to work, so I use floating decimals.)
3. Call your frame update method from within the UIAccelerometer update event:
- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration
[myView setNeedsDisplay];
The result is that myView should call drawRect as often as the UIAccelerometer updates. This may dip below your desired frame rate if things are too busy, but it seems to get as close to the rate you specify as possible. More importantly, it doesn't block touch events!
The downside, of course, is that you need to activate the accelerometer, which undoubtedly ***** up some resources (although I don't know how much.)
Anyway, I'd be curious to know if this works for anyone else.