手势识别器，异常行为（乘数效应）iOS

Question

我正在尝试向视图添加手势识别器。 当我同时添加平移（用于移动）和捏合（用于缩放）时，我得到一些奇怪的行为。

缩放视图（恰好包含imageView）后，平移手势识别器似乎会增加移动效果。 还是仍然假设原始比例，因此移动速度比预期的要快？

这是移动和缩放方法的代码：

//ivars for gesture recognizers/transforms
CGFloat scale;
CGFloat rotation;
CGPoint translatedPoint;
CGFloat _lastScale;
CGFloat _lastRotation;  
CGFloat _firstX;
CGFloat _firstY;

-(void)scale:(id)sender {
    if([(UIPinchGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan) {
        _lastScale = 1.0;
    }
    scale = 1.0 - (_lastScale - [(UIPinchGestureRecognizer*)sender scale]);
    CGAffineTransform currentTransform = gestureView.transform;
    CGAffineTransform newTransform = CGAffineTransformScale(currentTransform, scale, scale);
    [gestureView setTransform:newTransform];
    _lastScale = [(UIPinchGestureRecognizer*)sender scale];
    NSLog(@"gestureView origin x: %f, y: %f", gestureView.frame.origin.x, gestureView.frame.origin.y);
    NSLog(@"gestureView center x: %f, y: %f",[gestureView center].x, [gestureView center].y);
    NSLog(@"gestureView scale x: %f, scale y: %f", gestureView.frame.size.width, gestureView.frame.size.height);

}

-(void)move:(id)sender {
    translatedPoint = [(UIPanGestureRecognizer*)sender translationInView:gestureView];
    if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan) {
        _firstX = [gestureView center].x;
        _firstY = [gestureView center].y;
    }
    translatedPoint = CGPointMake(_firstX+translatedPoint.x, _firstY+translatedPoint.y);
    [gestureView setCenter:translatedPoint];
    NSLog(@"gestureView origin x: %f, y: %f", gestureView.frame.origin.x, gestureView.frame.origin.y);
    NSLog(@"gestureView center x: %f, y: %f",[gestureView center].x, [gestureView center].y);
}

这是项目： owolf.net/uploads/StackOverflow/GestureRecognizerTest.zip

谢谢阅读！

Answer 1

您需要在gestureView中进行翻译，这将为您提供缩放后的翻译。 如果将手势视图缩小到50％，则沿x轴移动10像素将使平移点值达到x = 20，这是因为“缩小”的手势视图（“高分辨率”）上的“外部” 10像素增加了一倍。

然后，将其应用于gestureView的框架（center是将框架设置为center.x - frame.size.width/2, center.y - frame.size.height/2, frame.size的便捷方法），这意味着它受规模的影响。

您可能想要做的就是更改translationInView:调用，以在gestureView.superview中gestureView.superview ，而不是在gestureView本身中gestureView 。