UITapGestureRecognizer 点击半径

Question

我有一个在屏幕上移动的UIImageView，我在图像中添加了一个UITapGestureRecognizer。这一切都很好而且很漂亮，但是，当图像开始在屏幕上移动得太快时，就会变得更难点击和被识别。

如果你看一下这张图片，你会看到一个围绕着 2 个简笔画的绿色方块。

假设，例如，您必须触摸绿色方块内部才能将其注册为“点击”。目前它就像顶部图像，但我想在底部图像中有一些额外的填充。那么如何让UITapGestureRecognizer的区域更大呢？

Answer 1

不要将点击手势识别器添加到图像视图中，而是将其添加到图像视图的超级视图中。遍历子视图以找到应该接收点击手势的视图。例如：

- (void)viewDidLoad
{
    [super viewDidLoad];

    UIView *containerView = [self view];

    UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap:)];
    [containerView addGestureRecognizer:tapRecognizer];
}

- (void)tap:(UITapGestureRecognizer *)sender
{
    UIView *containerView = [sender view];
    CGPoint location = [sender locationInView:containerView];

    for (UIView *subview in [[containerView subviews] reverseObjectEnumerator]) {
        if (![subview isKindOfClass:[UIImageView class]]) {
            continue;
        }
        if (CGRectContainsPoint([subview frame], location)) {
            [self imageViewTapped:(UIImageView *)subview];
            return;
        }
    }
}

- (void)imageViewTapped:(UIImageView *)imageView
{
    // do something when an image view is tapped
}