iPhone iOS如何将UILongPressGestureRecognizer和UITapGestureRecognizer添加到同一控件并防止冲突？

Question

我正在构建一个iPhone应用程序,让用户重新排列屏幕上的一些UI元素.

如何在同一个UIView中添加点击手势识别器和长按手势识别器？当我从长按中抬起手指时,轻敲手势识别器会触发.如何在用户执行长按时暂时禁用轻敲手势识别器或阻止其触发？

谢谢!

Answer 1

要允许两个手势一起工作,请实现以下委托方法:

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
    return YES;
}

为了使长按具有第一优先权,请执行以下操作:

[tapGesture requireGestureRecognizerToFail:longPress];

Answer 2

要成功结合您需要:

1º添加到标题处的界面手势委托

@interface ViewController : ViewController <UIGestureRecognizerDelegate>

2º创建手势事件并将视图添加到源文件中:

UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(touch:)];
    [tap setNumberOfTapsRequired:1]; // Set your own number here
    [tap setDelegate:self]; // Add the <UIGestureRecognizerDelegate> protocol

    UILongPressGestureRecognizer *longTap = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longTouch:)];
    [longTap setNumberOfTapsRequired:0]; // Set your own number here
    [longTap setMinimumPressDuration:1.0];
    [longTap setDelegate:self]; // Add the <UIGestureRecognizerDelegate> protocol
    [tap requireGestureRecognizerToFail:longTap];   // Priority long

    [self.view addGestureRecognizer:tap];
    [self.view addGestureRecognizer:longTap];

3º在源文件中添加回调:

- (void) touch: (UITapGestureRecognizer *)recognizer
{
    CGPoint location = [recognizer locationInView: self.HUDview];
    if (recognizer.state == UIGestureRecognizerStateBegan)
    {
        NSLog(@"touch UIGestureRecognizerStateBegan");
    }
    if (recognizer.state == UIGestureRecognizerStateEnded)
    {
        NSLog(@"touch UIGestureRecognizerStateEnded");
        //NSLog(@"Position of touch: %.3f, %.3f", location.x, location.y);    // Position landscape
    }
}

- (void) longTouch: (UILongPressGestureRecognizer *)recognizer
{
    if (recognizer.state == UIGestureRecognizerStateBegan)
    {
        NSLog(@"longTouch UIGestureRecognizerStateBegan");
    }
    if (recognizer.state == UIGestureRecognizerStateEnded)
    {
        NSLog(@"longTouch UIGestureRecognizerStateEnded");
    }
}

4º设置手势识别器可用:

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return YES;
}

Answer 3

作为替代方法,不要有两个单独的识别器 - 只需对两个事件使用LongPress识别器:

配置如下:

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

然后处理如下:

- (BOOL)longPressEvent:(UILongPressGestureRecognizer *)gesture {

    // _dragStarted is a class-level BOOL

    if(UIGestureRecognizerStateBegan == gesture.state) {
        _dragStarted = NO;
    }

    if(UIGestureRecognizerStateChanged == gesture.state) {
        _dragStarted = YES;
        // Do dragging stuff here
    }

    if(UIGestureRecognizerStateEnded == gesture.state) {

        if (_dragStarted == NO)
        {
            // Do tap stuff here

        }
        else
        {
            // Do drag ended stuff here
        }
    }

    return YES;

}