Question

我有一个UIImageView，我试图使用UIPanGestureRecognizer对象移动。 UIImageView位于UITableView的顶部，用作滚动条。我想让用户在UITableView上向上或向下移动这个UIImageView，而不是侧身。为此，我实现了UIGestureRecognizerDelegate，我有以下方法：

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {

     return YES;

}

- (void)panGestureDetected:(UIPanGestureRecognizer *)recognizer {

    NSLog(@"Do I get called?");
    //_startLocation is a property of type CGPoint that I declare in the .h file
    _startLocation = [recognizer locationInView:_imageView];

    NSLog(@"The point is: %d", _startLocation);

    CGRect frame = [_imageView frame];

    frame.origin.y += frame.origin.y - _startLocation.y;

    [_imageView setFrame: frame];

    _imageView.center = _startLocation;

}

方法panGestureDetected从viewDidLoad调用，如下所示：

UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGestureDetected:)];
    panGesture.maximumNumberOfTouches = 1;
    panGesture.minimumNumberOfTouches = 1;
    panGesture.delegate = self;
    [_table addGestureRecognizer:panGesture];

不幸的是，当我尝试移动它时，我的UIImageView在屏幕上疯狂移动。我希望看到一个平滑滚动的UIImageView在用户拖动时向上/向下移动。谁能看到我做错了什么？

Answer 1

在你的处理程序方法中，只需保留此行并删除所有其他行。

_imageView.center.y = [recognizer locationInView:[_imageView superView]].y;

您需要在superView中获取位置，而不是imageView本身。只需更改中心的y值。

尝试在iOS中使用gestureRecognizer正确移动UIImageView

1 个答案: