iPad应用程序-touchesBegan双击不正确

Question

我有一个 UIViewController，它有 TouchBegan 函数并输出位置。

- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { 
    NSLog(@"in");

    NSArray *touchesArray = [touches allObjects];
    for(int i=0; i<1; i++)
    {
        UITouch *touch = (UITouch *)[touchesArray objectAtIndex:i];
        CGPoint point = [touch locationInView:touch.view];
        NSLog(@"point = %f %f",point.x,point.y);
    }
}

如果我快速双击屏幕中间，我会得到以下输出，

2012-02-12 21:47:13.522 MoreMost[479:707] in
2012-02-12 21:47:13.523 MoreMost[479:707] point = 698.000000 86.000000
2012-02-12 21:47:13.617 MoreMost[479:707] in
2012-02-12 21:47:13.619 MoreMost[479:707] point = 39.000000 22.000000

为什么第二次点击被注册为 (39,22)...这就像 iPad 的左上角。不过，我是在中间敲击的。

所以，我想通过两种方式解决这个问题：

1) somehow, not let the user double tap (however it seems even when I double tap fast, the touchesBegan function is called on two separate occassions)
2) figure out why that 2nd tap is being registered with the wrong coordinates.

Answer 1

它应该是 CGPoint point = [touch locationInView:self.view];...而不是“touch.view”