在 UIScrollview 中禁用对角线拖动

Posted 2023-03-10

【中文标题】在 UIScrollview 中禁用对角线拖动

【英文标题】：Disable diagonal dragging in UIScrollview

【发布时间】：2017-05-02 06:57:54

【问题描述】：

我正在使用 UIScrollview 加载我的两个视图，比如说 A 和 B。如下图所示。我将 PagingEnabled 设置为 YES 并将 DirectionLockEnabled 设置为 YES。

当我将视图从 A 拖到 B 时，它是对角线的。请在下面找到代码，

- (void)setupScrollView:(UIScrollView*)scrMain 

    for (int i = 0; i < 2; i++) 
        if (i == 0) 
            // View A
            [ViewA setFrame:CGRectMake((i)*scrollview.frame.size.width + 20, 0, scrollview.frame.size.width - 40, ViewA.frame.size.height)];
            [scrollview addSubview:ViewA];
         else if (i == 1) 
           // View B
           [ViewB setFrame:CGRectMake((i)*ViewB.frame.size.width + 30, 0, scrollview.frame.size.width - 40, ViewB.frame.size.height)];
           [scrollview addSubview:ViewB];
        
    
    [scrollview setContentSize:CGSizeMake((scrollview.frame.size.width-15)*2, ViewB.frame.size.height)];


- (void) scrollViewWillBeginDragging: (UIScrollView *) scrollView

    self.oldContentOffset = scroller.contentOffset;


- (void) scrollViewDidScroll: (UIScrollView *) scrollView

    float XOffset = fabs(self.oldContentOffset.x - scrollView.contentOffset.x );
    float YOffset = fabs(self.oldContentOffset.y - scrollView.contentOffset.y );

    if (scrollView.contentOffset.x != self.oldContentOffset.x && (XOffset >= YOffset) )
    
        scrollView.pagingEnabled = YES;
        scrollDirection = ScrollDirectionHorizontal;
    
    else
    
        scrollView.pagingEnabled = NO;
        scrollDirection = ScrollDirectionVertical;
    

我查看了以下链接，但我还没有找到解决方案， http://bogdanconstantinescu.com/blog/proper-direction-lock-for-uiscrollview.html UIScrollView scrolling in only one direction at a time http://chandanshetty01.blogspot.ae/2012/07/restricting-diagonal-scrolling-in.html

感谢所有帮助！

【问题讨论】：

我这样做的方式是不允许包含页面的滚动视图滚动两种方式（所以在这种情况下只是水平滚动）。并允许该滚动视图中的视图（在本例中为 A 和 B）具有自己的滚动方式（在本例中为垂直）。

【参考方案1】：

重置滚动视图的 contentSize 后设置directionalLockEnabled = YES;

[self.scrollView setContentSize:CGSizeMake((self.scrollView.frame.size.width-15)*2, self.ViewB.frame.size.height)];
self.scrollView.directionalLockEnabled = YES; // add this here.

这样做可以解决你的问题

根据你的代码回答

- (void)viewDidLoad 
    [super viewDidLoad];
    [self setupScrollView:self.scrollView];
    self.scrollView.directionalLockEnabled = YES;
    // Do any additional setup after loading the view.


- (void)didReceiveMemoryWarning 
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.



- (void)setupScrollView:(UIScrollView*)scrMain 

for (int i = 0; i < 2; i++) 
    if (i == 0) 
        // View A
        self.ViewA = [[UIView alloc] init];
        self.ViewA.backgroundColor = [UIColor blackColor];
        [self.ViewA setFrame:CGRectMake((i)*self.scrollView.frame.size.width + 20, 0, self.scrollView.frame.size.width - 40, 800)];
        [self.scrollView addSubview:self.ViewA];
     else if (i == 1) 
        // View B
        self.ViewB = [[UIView alloc] init];
        self.ViewB.backgroundColor = [UIColor blueColor];
        [self.ViewB setFrame:CGRectMake((i)*self.ViewA.frame.size.width + 30, 0, self.scrollView.frame.size.width - 40, 800)];
        [self.scrollView addSubview:self.ViewB];
    

[self.scrollView setContentSize:CGSizeMake((self.scrollView.frame.size.width-15)*2, self.ViewB.frame.size.height)];
self.scrollView.directionalLockEnabled = YES;

【讨论】：

问题仍然存在。

奇怪.. 它为我工作。我现在试了一下，它对我有用。

能否请您发布您的完整代码。会很有用的

评论的行数更多，所以我在答案中编辑并添加了代码。

directionalLockEnabled 不会禁用对角滚动，请参阅：developer.apple.com/documentation/uikit/uiscrollview/…