查找使用UITapGestureRecognizer时点击的子视图

Question

当使用UIGestureRecognizers时，我如何知道事件发生在哪个子视图上？

根据文档：

手势识别器对特定视图和该视图的所有子视图的触摸进行命中测试。

据我所知，“view”属性是

手势识别器附加到的视图。

这将是父视图。

Answer 1

这将在事件的位置找到最内层的子视图。(请注意，如果该子视图有任何交互式的内部私有子视图，则此代码也会找到这些子视图。)

UIView* view = gestureRecognizer.view;
CGPoint loc = [gestureRecognizer locationInView:view];
UIView* subview = [view hitTest:loc withEvent:nil];

在Swift 2中：

let view = gestureRecognizer.view
let loc = gestureRecognizer.locationInView(view)
let subview = view?.hitTest(loc, withEvent: nil) // note: it is a `UIView?`

在Swift 3中：

let view = gestureRecognizer.view
let loc = gestureRecognizer.location(in: view)
let subview = view?.hitTest(loc, with: nil) // note: it is a `UIView?`

Answer 2

对于未来的用户...当世界不再使用obj-c时，我现在有了一个更好的选择…

[sender view]

这样使用它：

UITapGestureRecognizer * objTapGesture = [self createTapGestureOnView:myTextField];

[objTapGesture addTarget:self action:@selector(displayPickerView:)];

//添加这些方法

-(void)displayPickerView:(UITapGestureRecognizer*)sender
{
    UITextField *textField = (UITextField*)[sender view];
    NSLog(@"tag=  %ld", (long)textField.tag);
}

-(UITapGestureRecognizer*)createTapGestureOnView:(UIView *)view
{
    view.userInteractionEnabled = YES;
    UITapGestureRecognizer * tapGesture = [[UITapGestureRecognizer alloc]init];
    tapGesture.numberOfTapsRequired = 1;
    tapGesture.numberOfTouchesRequired = 1;
    [view addGestureRecognizer:tapGesture];
    return tapGesture;
}