使用 UIPanGestureRecognizer 移动时图片总是回到原点

Posted 2023-03-16

【中文标题】使用 UIPanGestureRecognizer 移动时图片总是回到原点

【英文标题】：Picture always move back to the origin during move with UIPanGestureRecognizer

【发布时间】：2015-05-18 05:34:59

【问题描述】：

我尝试以编程方式实现平移手势，但是当我尝试它时，uiview 总是在移动过程中移回超级视图内的原点位置。所以实际上它从原点来回跳转到新位置。 有谁知道问题出在哪里？

代码：

- (void)setGesture

    self.userInteractionEnabled = YES;
        UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(detectPan:)];
        self.gestureRecognizers = @[panRecognizer];




- (void) detectPan:(UIPanGestureRecognizer *) penGes

    if ((penGes.state == UIGestureRecognizerStateChanged) ||
        (penGes.state == UIGestureRecognizerStateEnded))
    

        CGPoint translation = [penGes translationInView:self.superview];
        self.center = CGPointMake(self.lastLocation.x + translation.x,
                              self.lastLocation.y + translation.y);

       [penGes setTranslation:CGPointZero inView:self];
    

- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

    // Promote the touched view
    [self.superview bringSubviewToFront:self];

    // Remember original location
    self.lastLocation = self.center;

【参考方案1】：

我认为您的翻译与自动布局约束冲突。 看看this answer 来自matt 的关于转换和自动布局的信息。