Question

我正在尝试向视图添加手势识别器。当我添加pan（用于移动）和pinch（用于缩放）时，我会得到一些奇怪的行为。

在视图（恰好包含imageView）被缩放后，平移手势识别器似乎会增加移动的效果。或者它仍然采用原始比例，因此移动速度比它应该更快？

以下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

感谢阅读！

Answer 1

您要求在gestureView中进行翻译，这将为您提供缩放的翻译。如果将gestureView缩小到50％，则沿x轴移动10个像素将使得translate64值中的x = 20，因为“在外部”的10个像素在按比例缩小（“更高分辨率”）的手势视图上加倍。 / p>

然后将其应用于gestureView的框架（中心只是一种方便的方法，将框架设置为center.x - frame.size.width/2, center.y - frame.size.height/2, frame.size），这意味着它受到比例的影响。

您可能要做的是更改translationInView:来电以查看gestureView.superview，而不是gestureView本身。

手势识别器，奇怪的行为（乘数效应）iOS

1 个答案: