当对象移动到某个帧时，如何停止UIPanGestureRecognizer

Question

我有一个使用UIPanGestureRecognizer移动的图像类型的对象，当对象到达某个帧时我需要停止识别UIPanGestureRecognizer。

    UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(move:)];
    [panRecognizer setMinimumNumberOfTouches:1];
    [panRecognizer setMaximumNumberOfTouches:1];
    [panRecognizer setDelegate:self];
    [templatePhotoPlaceholderView addGestureRecognizer:panRecognizer];

-(void)move:(UIPanGestureRecognizer *)gestureRecognizer
{
    CGPoint translatedPoint = [gestureRecognizer translationInView:templatePhotoPlaceholderView];

    if([gestureRecognizer state] == UIGestureRecognizerStateBegan) {
        _firstX = [imageview center].x;
        _firstY = [imageview center].y;
    }



    translatedPoint = CGPointMake(_firstX+translatedPoint.x, _firstY+translatedPoint.y);
    //NSLog(@" Move center point :%@", NSStringFromCGPoint(translatedPoint));

    [imageview setCenter:translatedPoint];  

}

我怎么能这样做？

Answer 1

UIGestureRecognizers具有已启用的属性。文档：

  

禁用手势识别器，使其无法接收触摸。该   默认值为YES。如果在a时将此属性更改为NO   手势识别器当前正在识别手势，手势   识别器转换为已取消状态。

编辑：

只需将enabled属性设置为NO。

gestureRecognizer.enabled = NO;

Answer 2

当您需要阻止UIPanGestureRecognizer识别手势时，您只需将此代码行（如jbat100所述）放在-(void)move:(UIPanGestureRecognizer *)gestureRecognizer中：

gestureRecognizer.enabled = NO;

在此行之后，您的gestureRecognizer状态设置为"UIGestureRecognizerStateCancelled"

然后只需在您的-(void)move:(UIPanGestureRecognizer *)gestureRecognizer函数中添加几行：

if ([gestureRecognizer state] == UIGestureRecognizerStateCancelled) {
     gestureRecognizer.enabled = YES;
}

您将能够使用手势识别器

修改：

这是代码段：

- (void)move:(UIPanGestureRecognizer *)gestureRecognizer {
    BOOL cancelPanGesture = YES;
    if (cancelPanGesture) {
        /* 
         After this line gesture recognizer will be disabled, state will be UIGestureRecognizerStateCancelled
         and this method (move:) will fire one more time.
         */
        gestureRecognizer.enabled = NO;
    }
    if (gestureRecognizer.state == UIGestureRecognizerStateCancelled) {
        gestureRecognizer.enabled = YES;
    }
}

Answer 3

设置pangesture.delegate = self，并实现委托方法

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
     //return NO when you reach the frame
}