Question

我用点击手势识别器点击了一个视图，工作得很好。但我希望在触摸发生时突出显示视图，并在触摸结束时将其移除。

我试过这个：

- (IBAction)refresh:(UITapGestureRecognizer *)sender {
    if(self.currentStatus == NODATA){
        if(sender.state == UIGestureRecognizerStateBegan){
            NSLog(@"Began!");
            [self.dashboardViewController.calendarContainer state:UIViewContainerStatusSELECTED];
        }
        if (sender.state == UIGestureRecognizerStateEnded){
             NSLog(@"%@", @"Ended");
            [self.dashboardViewController.calendarContainer state:UIViewContainerStatusNORMAL];
        } 
        [self setState:REFRESHING data:nil];
    }
}

“已完成”的NSLog显示但是开始没有显示，所以它永远不会被选中。这是为什么？

Answer 1

UITapGestureRecognizer永远不会进入UIGestureRecognizerStateBegan州。只有连续手势（例如滑动或捏合）才会使识别器从UIGestureRecognizerStatePossible转到UIGestureRecognizerStateBegan。离散手势，例如点按，将其识别器直接放入UIGestureRecognizerStateRecognized，即单击一下，直接进入UIGestureRecognizerStateEnded。

那就是说，也许你正在寻找一个UILongPressGestureRecognizer，这是一个连续的识别器，它会进入UIGestureRecognizerStateBegan，让你能够辨别触摸的开始和结束？

Answer 2

可能为时已晚。但是，如果您严格要使用手势识别器，这也会对您有所帮助。

   UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]
                                         initWithTarget:self 
                                         action:@selector(refresh:)];
    longPress.minimumPressDuration = 0.0;

 - (IBAction)refresh:(UILongPressGestureRecognizer *)sender {
     if(self.currentStatus == NODATA){
       if(sender.state == UIGestureRecognizerStateBegan){
         NSLog(@"Began!");
         [self.dashboardViewController.calendarContainer state:UIViewContainerStatusSELECTED];
       }
       if (sender.state == UIGestureRecognizerStateEnded){
         NSLog(@"%@", @"Ended");
        [self.dashboardViewController.calendarContainer state:UIViewContainerStatusNORMAL];
       } 
       [self setState:REFRESHING data:nil];
    }
   }

Answer 3

您还可以使用touchesBegan:withEvent:和touchesEnded:withEvent:方法。

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    NSSet *t = [event touchesForView:_myView];
    if([t count] > 0) {
        // Do something 
    }
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    NSSet *t = [event touchesForView:_myView];
    if([t count] > 0) {
        // Do something
    }
}

Answer 4

Swift 4.2

let recognizer = UILongPressGestureRecognizer(target: self, action: Selector("touched:"))
recognizer.delegate = self
recognizer.minimumPressDuration = 0.0
addGestureRecognizer(recognizer)
userInteractionEnabled = true

/**
 * Gesture handler
 */   
@objc func touched(sender: UILongPressGestureRecognizer) {
    if sender.state == .began {
        /*onPressed*/
    } else if sender.state == .ended {
        /*onReleased*/
    }
}

Answer 5

一个古老的问题，但仍然存在。希望它将对某人有所帮助。如果我对作者的问题的回答正确，则其目的是检测水龙头是否已开始识别并执行操作。就像您不希望目标仅在用户释放手指时才触发，而在用户第一次触摸时已经触发。

一种简单的方法是对UITapGestureRecognizer进行扩展，如下所示：

fileprivate class ModTapGestureRecognizer: UITapGestureRecognizer {
    
    var onTouchesBegan: (() -> Void)?
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
        onTouchesBegan?()
        super.touchesBegan(touches, with: event)
    } 
}

稍后在您的代码中可以像这样使用它：

let tapRecognizer = ModTapGestureRecognizer()
tapRecognizer.addTarget(self, action: #selector(didTapped))
tapRecognizer.onTouchesBegan = {
   print("Yep, it works")
}
yourView.addGestureRecognizer(tapRecognizer)

您真棒！

iOS点击手势状态开始没有命中

5 个答案:

Swift 4.2