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我正在尝试将手势识别器添加到视图中。当我同时添加平移（移动）和捏（缩放）时，我得到了一些奇怪的行为。

在视图（恰好包含一个 imageView）被缩放后，平移手势识别器似乎增加了移动的效果。或者它仍然假设原始比例，所以移动速度比它应该的要快？

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

谢谢阅读！

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1 回答 1

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您要求在手势视图中进行翻译，这将为您提供缩放的翻译。如果将手势视图缩小到 50%，则沿 x 轴移动 10 像素将在 translatePoint 值中给出 x=20，因为“外部”的 10 像素在缩小（“更高分辨率”）手势视图上翻倍。

然后，您将其应用到gestureView 的框架（center 只是一种将框架设置为的便捷方法center.x - frame.size.width/2, center.y - frame.size.height/2, frame.size），这意味着它会受到比例的影响。

您可能想要做的是将translationInView:调用更改为 look in gestureView.superview，而不是更改其gestureView本身。

于 2012-08-10T08:36:59.847 回答