拖動和旋轉手勢在iPad上

Question

我有一個問題，我想一些姿態加入到了移動一個UIButton和旋轉它，我用這個代碼

[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]; 
     } 
    } 

所有的工作，我可以旋轉按鈕，移動按鈕，問題是如果我旋轉按鈕，然後移動它...在這種情況下不工作，我可以移動按鈕，但不是我想要的地方...問題在哪裏？

Answer 1

您正在計算觸摸位置相對於按鈕的差異。當按鈕旋轉時，這不起作用。相反，您應該嘗試相對於按鈕或窗口的超視圖來計算它。

取而代之的是：

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

你應該使用這樣的：

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