iOS开发上下滑动UIScrollview隐藏或者显示导航栏的实例

野性酷女 2022-04-11 13:54 524阅读 0赞

**一、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

[?][Link 1]

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> <code>self.navigationController.hidesBarsOnSwipe = YES;</code> </td> 
 </tr> 
 </tbody> 
</table>

swift代码如下

[?][Link 1]

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> <code>self.navigationController?.hidesBarsOnSwipe = true</code> </td> 
 </tr> 
 </tbody> 
</table>

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

[?][Link 1]

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 </td> 
 <td> <code>- (void)scrollViewDidScroll:(UIScrollView *)scrollView</code> <code>{ </code> <code>&nbsp;</code><code>//scrollView已经有拖拽手势，直接拿到scrollView的拖拽手势</code> <code>&nbsp;</code><code>UIPanGestureRecognizer *pan = scrollView.panGestureRecognizer;</code> <code>&nbsp;</code><code>//获取到拖拽的速度 &gt;0 向下拖动 &lt;</code><code>0</code> <code>向上拖动</code> <code>&nbsp;</code><code>CGFloat velocity = [pan velocityInView:scrollView].y;</code> <code>&nbsp;</code>&nbsp; <code>&nbsp;</code><code>if (velocity &lt;- 5) { </code> <code>&nbsp;&nbsp;</code><code>//向上拖动，隐藏导航栏</code> <code>&nbsp;&nbsp;</code><code>[self.navigationController setNavigationBarHidden:YES animated:YES];</code> <code>&nbsp;</code><code>}else if (velocity &gt; 5) { </code> <code>&nbsp;&nbsp;</code><code>//向下拖动，显示导航栏</code> <code>&nbsp;&nbsp;</code><code>[self.navigationController setNavigationBarHidden:NO animated:YES];</code> <code>&nbsp;</code><code>}else if(velocity == 0){ </code> <code>&nbsp;&nbsp;</code><code>//停止拖拽</code> <code>&nbsp;</code><code>}</code> <code>}</code> </td> 
 </tr> 
 </tbody> 
</table>

swift代码如下

[?][Link 1]

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 4 5 6 7 8 9 10 11 </td> 
 <td> <code>func scrollViewDidScroll(scrollView: UIScrollView) { </code> <code>&nbsp;&nbsp;&nbsp;</code>&nbsp; <code>&nbsp;&nbsp;</code><code>let pan = scrollView.panGestureRecognizer </code> <code>&nbsp;&nbsp;</code><code>let velocity = pan.velocityInView(scrollView).y </code> <code>&nbsp;&nbsp;</code><code>if velocity &lt; -5 { </code> <code>&nbsp;&nbsp;&nbsp;</code><code>self.navigationController?.setNavigationBarHidden(true, animated: true) </code> <code>&nbsp;&nbsp;</code><code>} else if velocity &gt; 5 { </code> <code>&nbsp;&nbsp;&nbsp;</code><code>self.navigationController?.setNavigationBarHidden(false, animated: true) </code> <code>&nbsp;&nbsp;</code><code>} </code> <code>&nbsp;&nbsp;&nbsp;</code>&nbsp; <code>&nbsp;</code><code>}</code> </td> 
 </tr> 
 </tbody> 
</table>

这种效果最好

**3.使用UIScrollViewDelegate另一个代理方法**

Objective-C代码如下

[?][Link 1]

<table> 
 <tbody> 
 <tr> 
 <td> 1 </td> 
 <td> <code>- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset&lt;/</code><code>span</code><code>&gt;</code> </td> 
 </tr> 
 </tbody> 
</table>

[?][Link 1]

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 4 5 6 7 </td> 
 <td> <code>{ </code> <code>&nbsp;</code><code>if (velocity.y &gt; 0.0) { </code> <code>&nbsp;&nbsp;</code><code>[self.navigationController setNavigationBarHidden:YES animated:YES]; </code> <code>&nbsp;</code><code>} else if (velocity.y &lt; 0.0){ </code> <code>&nbsp;&nbsp;</code><code>[self.navigationController setNavigationBarHidden:NO animated:YES]; </code> <code>&nbsp;</code><code>} </code> <code>}</code> </td> 
 </tr> 
 </tbody> 
</table>

swift代码如下

[?][Link 1]

<table> 
 <tbody> 
 <tr> 
 <td> 1 2 3 4 5 6 7 </td> 
 <td> <code>func scrollViewWillEndDragging(scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer&lt;</code><code>CGPoint</code><code>&gt;) { </code> <code>&nbsp;&nbsp;</code><code>if velocity.y &gt; 0 { </code> <code>&nbsp;&nbsp;&nbsp;</code><code>self.navigationController?.setNavigationBarHidden(true, animated: true) </code> <code>&nbsp;&nbsp;</code><code>} else if velocity.y &lt; 0 { </code> <code>&nbsp;&nbsp;&nbsp;</code><code>self.navigationController?.setNavigationBarHidden(false, animated: true) </code> <code>&nbsp;&nbsp;</code><code>} </code> <code>&nbsp;</code><code>}</code> </td> 
 </tr> 
 </tbody> 
</table>

**二、总结：三种方法都可以,我个人觉得第二种方法效果最好,大家可以学习借鉴一下**

以上这篇iOS开发上下滑动UIScrollview隐藏或者显示导航栏的实例就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持脚本之家。

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