Question

我有一个问题，我想添加一些手势给一个uibutton移动并旋转它，我使用这个代码

    [self.button addTarget:self action:@selector(wasDragged:withEvent:) forControlEvents:UIControlEventTouchDragInside];

    UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(handleRotate:)];
    [self.button addGestureRecognizer:rotationGesture];

- (void)wasDragged:(UIButton *)button withEvent:(UIEvent *)event
    {
        // get the touch
        UITouch *touch = [[event touchesForView:self.button] anyObject];

        // get delta
        CGPoint previousLocation = [touch previousLocationInView:self.button];
        CGPoint location = [touch locationInView:self.button];
        CGFloat delta_x = location.x - previousLocation.x;
        CGFloat delta_y = location.y - previousLocation.y;

        // move button
        self.button.center = CGPointMake(self.button.center.x + delta_x,self.button.center.y + delta_y);

    }

    - (void)handleRotate:(UIRotationGestureRecognizer *)recognizer {
        if(recognizer.state == UIGestureRecognizerStateBegan || recognizer.state == UIGestureRecognizerStateChanged)
        {
            recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform, recognizer.rotation);
            [recognizer setRotation:0];
        }
    }

所有工作我可以旋转按钮并移动按钮，问题是如果我旋转按钮然后移动它...在这种情况下不起作用，我可以移动按钮但不是我想要的地方...问题是什么？

Answer 1

您正在计算触摸相对于按钮的位置之间的差异。旋转按钮时，这不能按预期工作。相反，你应该尝试相对于按钮或窗口的超级视图计算它。

而不是：

    CGPoint previousLocation = [touch previousLocationInView:self.button];
    CGPoint location = [touch locationInView:self.button];

你应该用这个：

    CGPoint previousLocation = [touch previousLocationInView:self.button.superview];
    CGPoint location = [touch locationInView:self.button.superview];

拖拽在iPad上旋转手势

1 个答案: