我正在构建的iphone应用程序中无法使用多点触控功能

Question

I have the following code:

- (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];
}

When I run it, it never detects more than one touch. Is there some setting that may prevent my app from taking multiple touches? Or am I missing something here?

Answer 1

You need to enable "Multiple Touch" on your View in InterfaceBuilder

alt text http://img.skitch.com/20090227-rpkafsxtg56pujk1h1583if88i.jpg

or if you have created the View in code it's set with

[theView setMultipleTouchEnabled:YES];

Answer 2

Also know that you will only get multiple touches in touchesMoved if both fingers are moving at the same time . If you have a single finger fixed on the screen, and move a second finger around, the phone will only report the finger that is moving.