UIPanGestureRecognizer 和 UIPinchGestureRecogizer 用于放大和移动反弹-拉回动画

Question

我在 UIView 中有 UIImageView。 请假设用户只能放大（不在此代码中）。 如果 uiimage 比 UIView 大，我需要拉回 uiimage 的动画，就像在 facebook 应用程序中一样。

意思是，如果用户将 UIImageView 向上移动..当他抬起手指时，UIImageView 将被拉回以覆盖底部的空白空间。

我试着玩它，但是..没有运气。 提前致谢

-(void)pinchGestureDetected:(UIPinchGestureRecognizer *)recognizer
{

    UIGestureRecognizerState state = [recognizer state];

    if (state == UIGestureRecognizerStateBegan || state == UIGestureRecognizerStateChanged)
    {

        CGFloat scale = [recognizer scale];



        [recognizer.view setTransform:CGAffineTransformScale(recognizer.view.transform, scale, scale)];

        [recognizer setScale:1.0];
    }


   }
- (void)panGestureDetected:(UIPanGestureRecognizer *)recognizer
{
    UIGestureRecognizerState state = [recognizer state];

    if (state == UIGestureRecognizerStateBegan || state == UIGestureRecognizerStateChanged)
    {
        CGPoint translation = [recognizer translationInView:recognizer.view];
        [recognizer.view setTransform:CGAffineTransformTranslate(recognizer.view.transform, translation.x, translation.y)];
        [recognizer setTranslation:CGPointZero inView:recognizer.view];
    }

}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return ![gestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]];
}

Answer 1

如果您的图像大于其容器，则应该可以使用：

- (void)panGestureDetected:(UIPanGestureRecognizer *)recognizer
{
    UIGestureRecognizerState state = [recognizer state];

    if (state == UIGestureRecognizerStateBegan || state == UIGestureRecognizerStateChanged)
    {
        CGPoint translation = [recognizer translationInView:recognizer.view];
        [recognizer.view setTransform:CGAffineTransformTranslate(recognizer.view.transform, translation.x, translation.y)];
        [recognizer setTranslation:CGPointZero inView:recognizer.view];
    }
    else if(state==UIGestureRecognizerStateEnded){
        UIView *imageView = recognizer.view;
        UIView *container = imageView.superview;

        CGFloat targetX = CGRectGetMinX(imageView.frame);
        CGFloat targetY = CGRectGetMinY(imageView.frame);


        if(targetX>0){
            targetX = 0;
        }else if(CGRectGetMaxX(imageView.frame)<CGRectGetWidth(container.bounds)){
            targetX = CGRectGetWidth(container.bounds)-CGRectGetWidth(imageView.frame);
        }

        if(targetY>0){
            targetY = 0;
        }else if(CGRectGetMaxY(imageView.frame)<CGRectGetHeight(container.bounds)){
            targetY = CGRectGetHeight(container.bounds)-CGRectGetHeight(imageView.frame);
        }

        [UIView animateWithDuration:0.3 animations:^{
            imageView.frame = CGRectMake(targetX, targetY, CGRectGetWidth(imageView.frame), CGRectGetHeight(imageView.frame));
        }];
    }
}