本文介绍了旋转iPhone中触摸拖动对应的图像的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想顺时针或逆时针旋转图像，对应于用户触摸拖动的速度.我认为这可以通过一些数学和逻辑来完成.用于此的代码示例是什么样的?
I want to rotate the image in clockwise or anticlockwise direction corresponding to the user touch drag with its speed. I think this can be done with some math and logic. What would a code sample for this look like?
推荐答案
如果你的目标是 iOS 3.2 或更高版本，你可以使用 UIRotationGestureRecognizer.代码看起来像这样:
If you're targeting iOS 3.2 or greater, you can use UIRotationGestureRecognizer. The code would look something like this:
在您的设置方法中(viewDidLoad 或 init 等):
In your setup method (viewDidLoad or init, etc,):
UIRotationGestureRecognizer *rotationGesture =
[[UIRotationGestureRecognizer alloc] initWithTarget:self
action:@selector(handleRotate:)];
rotationGesture.delegate = self;
[myImageView addGestureRecognizer:rotationGesture];
[rotationGesture release];
事件处理程序:
- (void)handleRotate:(UIRotationGestureRecognizer *)recognizer {
if(recognizer.state == UIGestureRecognizerStateBegan ||
recognizer.state == UIGestureRecognizerStateChanged)
{
recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform,
recognizer.rotation);
[recognizer setRotation:0];
}
}
我在 github 上有更多手势识别器示例(包括上面的那个).
I have some more examples of gesture recognizers (including the one above) on github.
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