多点触控在我正在开发的iphone应用程序中不起作用

I have the following code:

我有以下代码:

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {


NSUInteger touchCount = 0;
// Enumerates through all touch objects
for (UITouch *touchb in touches){
    touchCount++;
}


// When multiple touches, report the number of touches. 
if (touchCount > 1) {
    lblStatustouch.text = [NSString stringWithFormat:@"Tracking %d touches", touchCount];
} else {
    lblStatustouch.text = [NSString stringWithFormat:@"Tracking 1 touch", touchCount];
}
- (void)