iOS滑动手势UIPanGestureRecognizer 注意事项

今天在做侧滑页面时,发现页面随着滑动手势而滑动,到临界点时,如果再滑动会出现抖动现象.找到解决办法是进入方法后先判断一次,再判断是在滑动范围内让页面滑动.遂将滑动手势(UIPanGestureRecognizer )注意事项总结了如下:

代码:

- (void)panAction:(UIPanGestureRecognizer *)pan{

_canLeft = YES;

_canRight = YES;

//点相对于上一个点的位置

CGPoint moviePoint = [pan translationInView:pan.view];

//点的速度(正负可判断滑动趋势)

CGPoint velocity = [pan velocityInView:pan.view];

//侧滑的范围

CGFloat instance = kScreenWidth - 100;

//禁止左划的情况(在最左边时)

if (pan.view.left <= 0 && moviePoint.x <= 0) {

_canLeft = NO;

}

//禁止右划得情况(在最右边时)

if (pan.view.left >= instance && moviePoint.x >= 0) {

_canRight = NO;

}

//页面可以滑动的条件

if (_canRight && _canLeft && pan.view.left >= 0 && pan.view.left <= instance){

//移动

pan.view.center =

CGPointMake(pan.view.center.x + moviePoint.x, pan.view.center.y);

}

//每次都需要复位

[pan setTranslation:CGPointZero inView:pan.view];

//松开手指时判断滑动趋势让其归位

if (pan.state == UIGestureRecognizerStateEnded) {

if (pan.view.left < 10) {

pan.view.left = 0;

}else if(pan.view.left > instance - 10){

pan.view.left = instance;

}

}

}