UIPanGestureRecognizer获取所有触摸的线索

Question

我添加了以下手势识别器:

UIPanGestureRecognizer *d2 = [[UIPanGestureRecognizer alloc] 
                              initWithTarget:self 
                              action:@selector(ViewDragging2:)];
[d2 setMinimumNumberOfTouches:2];
[d2 setMaximumNumberOfTouches:2];
[targetView addGestureRecognizer:d2];

以及在该事件发生时触发的方法是:

-(void)ViewDragging2:(UIPanGestureRecognizer*)sender {

    // some point
    CGPoint translatedPoint = [(UIPanGestureRecognizer*)sender translationInView:targetView];
}

即使我用两根手指触摸,这也是我一触即发的重点.如何检索第一次和第二次触摸的线？

Answer 1

您可以使用以下方法访问所有触摸:

• (NSUInteger)numberOfTouches
• (CGPoint)locationOfTouch:(NSUInteger)touchIndex inView:(UIView *)view

它们在基类UIGestureRecognizer中定义.