ios – 试图理解TranslationInView

在我的UITableViewCell子类中,我添加了一个平移手势,在gestureRecognizerShouldBegin方法中,我检查了self.frame.origin.x和self.frame.origin.y,它们都是0.000000和0.000000,并且应用了TranslationInView CGPoint translation = [gestureRecognizer translationInView：[self superview] ].我得到x = -4.000000和y = 0.000000

TranslationInView如何工作,我试图绕过它,当我得到单元格0.0和0.0的正确位置,因为第一个单元格将具有0.0和0.0,为什么我需要TranslationInView.

- (void) pan: (UIPanGestureRecognizer *) recognizer
{
 if ((recognizer.state == UIGestureRecognizerStateChanged)||(recognizer.state ==    UIGestureRecognizerStateEnded)) {
    CGPoint translation = [recognizer translationInView:self];
    }
}