顺利隐藏导航栏

Posted 2023-04-13

【中文标题】顺利隐藏导航栏

【英文标题】：smoothly Hidden navigation bar

【发布时间】：2014-07-12 06:26:02

【问题描述】：

如何在不调整视图框架（或 tableView）的情况下做到这一点？ 我使用此代码并调整了视图大小，然后向下/向上滚动 我使用代码，而不是故事板

 - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
 
if ([gestureRecognizer class] == [UIPanGestureRecognizer class])

    UIPanGestureRecognizer *panGestureRec = (UIPanGestureRecognizer *)gestureRecognizer;
    CGPoint distance = [panGestureRec translationInView:self.tableView];

    if (distance.y > 0 || distance.y < 0)
    
        if (distance.y > 0) // down
        
            //NSLog(@"user swiped down");
            [self.navigationController setNavigationBarHidden:YES animated:YES];

         else if (distance.y < 0) //up
        
            //NSLog(@"user swiped up");
            [self.navigationController setNavigationBarHidden:NO animated:YES];
        

        return NO;
     else 
        return YES;
    

return YES;

【参考方案1】：

试试这个代码。这将提供流畅的动画（使用 UIView 动画属性）

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
 
if ([gestureRecognizer class] == [UIPanGestureRecognizer class])


    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:2];

    UIPanGestureRecognizer *panGestureRec = (UIPanGestureRecognizer *)gestureRecognizer;
    CGPoint distance = [panGestureRec translationInView:self.tableView];

    if (distance.y > 0 || distance.y < 0)
    
        if (distance.y > 0) // down
        
            //NSLog(@"user swiped down");
            [self.navigationController setNavigationBarHidden:YES animated:YES];

         else if (distance.y < 0) //up
        
            //NSLog(@"user swiped up");
            [self.navigationController setNavigationBarHidden:NO animated:YES];
        

        return NO;
     else 
        return YES;
    

   [UIView commitAnimations];

return YES;

【讨论】：

将 UIView 动画代码放入 if 条件中（if (distance.y > 0 || distance.y