本文介绍了旋转与iPhone中的触摸拖动相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,以使其与用户触摸拖动相对应。我认为可以通过一些数学和逻辑来完成。
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
如果目标是iOS 3.2或更高版本,则可以使用 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];
}
}
我还有更多的手势识别器示例(包括上面的一个)在上。
I have some more examples of gesture recognizers (including the one above) on github.
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