Question

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

根据文件：

手势识别器可以操作接触到特定视图的测试以及该视图的所有子视图。

据我所知，'view'属性是

手势识别器的视图附于。

这将是父视图。

Answer 1

这将在事件的位置找到最里面的后代视图。（请注意，如果该子视图具有任何交互式内部私有孙子，则此代码也会找到它们。）

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...... 现在，当世界不再使用obj-c时，我有了更好的选择......

[sender view]

以这种方式使用它：

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;
}

查找使用UITapGestureRecognizer时点击了哪个子视图

2 个答案: