当我在手机上玩游戏时，我注意到我的 UISegmentedControl 不是很灵敏。让我的水龙头注册需要 2 次或更多次尝试。所以我决定在模拟器中运行我的应用程序，以更准确地探测问题所在。通过用鼠标单击数十次，我确定 UISegmentedControl 的前 25% 没有响应(在下面的屏幕截图中，该部分用 Photoshop 以红色突出显示)。我不知道有任何不可见的 UIView 可能会阻止它。你知道如何使整个控件可点击吗？

self.segmentedControl = [[UISegmentedControl alloc] initWithItems:[NSArray arrayWithObjects:@"Uno", @"Dos", nil]];
self.segmentedControl.selectedSegmentIndex = 0;
[self.segmentedControl addTarget:self action:@selector(segmentedControlChanged:) forControlEvents:UIControlEventValueChanged];
self.segmentedControl.height = 32.0;
self.segmentedControl.width = 310.0;
self.segmentedControl.segmentedControlStyle = UISegmentedControlStyleBar;
self.segmentedControl.tintColor = [UIColor colorWithWhite:0.9 alpha:1.0];
self.segmentedControl.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin;

UIView* toolbar = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.width, HEADER_HEIGHT)];
toolbar.autoresizingMask = UIViewAutoresizingFlexibleWidth;
CAGradientLayer *gradient = [CAGradientLayer layer];
    gradient.frame = CGRectMake(
        toolbar.bounds.origin.x,
        toolbar.bounds.origin.y,
        // * 2 for enough slack when iPad rotates
        toolbar.bounds.size.width * 2,
        toolbar.bounds.size.height
    );
    gradient.colors = [NSArray arrayWithObjects:
        (id)[[UIColor whiteColor] CGColor],
        (id)[[UIColor 
            colorWithWhite:0.8
            alpha:1.0
            ] CGColor
        ],
        nil
];
[toolbar.layer insertSublayer:gradient atIndex:0];
toolbar.backgroundColor = [UIColor navigationBarShadowColor];
[toolbar addSubview:self.segmentedControl];

UIView* border = [[UIView alloc] initWithFrame:CGRectMake(0, HEADER_HEIGHT - 1, toolbar.width, 1)];
border.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleTopMargin;
border.backgroundColor = [UIColor colorWithWhite:0.7 alpha:1.0];
border.autoresizingMask = UIViewAutoresizingFlexibleWidth;
[toolbar addSubview:border];

[self.segmentedControl centerInParent];

self.tableView.tableHeaderView = toolbar;

最佳答案

正如其他答案中已经写的那样， UINavigationBar 捕获了导航栏本身附近的触摸，但不是因为它有一些延伸到边缘的 subview :这不是原因。

如果您记录整个 View 层次结构，您将看到 UINavigationBar 没有延伸到定义的边缘。

它收到触摸的原因是另一个:

在 UIKit 中，有很多“特殊情况”，这就是其中之一。

当您点击屏幕时，会启动一个称为“ HitTest ”的过程。从第一个 UIWindow 开始，所有 View 都被要求回答两个“问题”:点是否在您的边界内被点击？必须接收触摸事件的 subview 是什么？

这个问题是通过这两种方法来回答的:

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event;
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event;

-(CGPoint)warpPoint:(CGPoint)point;

[UINavigationBar, _isChargeEnabled]
[UINavigationBar, isEnabled]
[UINavigationBar, _isAlphaHittableAndHasAlphaHittableAncestors]

-(CGPoint)warpPoint:(CGPoint)point;
{
    return point;
}

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
    // this method is not safe if you tap the screen two times at the same x position and y position different for 16px, because it moves the point
    if (self.lastPoint.x == point.x)
    {
        // the points are on the same vertical line
        if ((0 < (self.lastPoint.y - point.y)) && ((self.lastPoint.y - point.y) < 16) )
        {
            // there is a differenc of ~15px in the y position?
            // if so, the point has been changed
            point.y = self.lastPoint.y;
        }
    }

    self.lastPoint = point;

    return [super hitTest:point withEvent:event];
}

关于ios - 为什么我的 UISegmentedControl 的顶部不可点击？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/17683970/