UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panIt:)];  // 初始化手势类

[view  addGestureRecognizer:panGesture];   // 将手势类添加给view

- (void)panIt:(UIPanGestureRecognizer *)panGesture

{

CGPoint pos = [pan locationInView:panGesture.view];    // 获取中心点

pan.state;   // 手势状态

UIGestureRecognizerStatePossible,

UIGestureRecognizerStateBegan,

UIGestureRecognizerStateChanged,

....................

}