iOS开发上下滑动UIScrollview隐藏或者显示导航栏
好多App都有上下滑动UIScrollview隐藏或者显示导航栏,在这里我说说我觉得有用的几种方法:
1.iOS8之后系统有一个属性hidesBarsOnSwipe
Objective-C代码如下
self.navigationController.hidesBarsOnSwipe=YES;
swift代码如下
self.navigationController?.hidesBarsOnSwipe=true
当使用以上代码时,可以达到效果
2.使用UIScrollViewDelegate一个代理方法
Objective-C代码如下
- (void)scrollViewDidScroll:(UIScrollView*)scrollView
{
//scrollView已经有拖拽手势，直接拿到scrollView的拖拽手势
UIPanGestureRecognizer*pan = scrollView.panGestureRecognizer;
//获取到拖拽的速度 >0 向下拖动 <0 向上拖动
CGFloat velocity = [panvelocityInView:scrollView].y;
if(velocity <-5) {
//向上拖动，隐藏导航栏
[self.navigationControllersetNavigationBarHidden:YESanimated:YES];
}elseif(velocity >5) {
//向下拖动，显示导航栏
[self.navigationControllersetNavigationBarHidden:NOanimated:YES];
}elseif(velocity ==0){
//停止拖拽
}
}
swift代码如下
func scrollViewDidScroll(scrollView: UIScrollView) {
let pan = scrollView.panGestureRecognizer
let velocity = pan.velocityInView(scrollView).y
ifvelocity < -5{
self.navigationController?.setNavigationBarHidden(true,animated:true)
}elseifvelocity >5{
self.navigationController?.setNavigationBarHidden(false,animated:true)
}
}
这种效果最好
3.使用UIScrollViewDelegate另一个代理方法
Objective-C代码如下
- (void)scrollViewWillEndDragging:(UIScrollView*)scrollViewwithVelocity:(CGPoint)velocitytargetContentOffset:(inoutCGPoint*)targetContentOffset
{
if(velocity.y>0.0) {
[self.navigationControllersetNavigationBarHidden:YESanimated:YES];
}elseif(velocity.y<0.0){
[self.navigationControllersetNavigationBarHidden:NOanimated:YES];
}
}
swift代码如下
func scrollViewWillEndDragging(scrollView: UIScrollView, withVelocityvelocity: CGPoint,targetContentOffset: UnsafeMutablePointer) {
ifvelocity.y>0{
self.navigationController?.setNavigationBarHidden(true,animated:true)
}elseifvelocity.y<0{
self.navigationController?.setNavigationBarHidden(false,animated:true)
}
}
以上内容转载：http://blog.csdn.net/wgl_happy/article/details/51791937
