ios - 如何正确拖放、旋转和缩放 UIView？
<p><p>在我的 iOS 应用程序中，我使用 UITouchGestureRecognizer 拖放、缩放和旋转 UIImageView。我还将信息存储在 ImageView 的最后位置，以便在应用重新启动时检索它。</p>
<p>这在 iOS7 上运行良好，但我最近开始在 iOS8 上进行测试，但遇到了一些问题，尤其是在缩放方面。每当 ImageView 在旋转参数中具有非 0 角度时，缩放就不会像预期的那样起作用并减小图像的大小。</p>
<p>我不明白操作系统为什么会这样，这是我的代码:</p>
<pre><code>-(void) viewDidAppear:(BOOL)animated{
;
;
for (GIFavorite *favorite in self.favorites){
UIImage *image = favorite.image;
ImageView *imageView = [ initWithFrame:CGRectMake(0, 0, image.size.width, image.size.height)];
imageView.center = CGPointMake(favorite.x, favorite.y);
imageView.transform = CGAffineTransformMakeRotation(favorite.rotation);
imageView.transform = CGAffineTransformScale(imageView.transform, favorite.scale, favorite.scale);
imageView.image = image;
imageView.userInteractionEnabled = YES;
UIPanGestureRecognizer * panRecognizer = [ initWithTarget:self action:@selector(handlePan:)];
panRecognizer.delegate = self;
;
UIRotationGestureRecognizer * rotationRecognizer = [ initWithTarget:self action:@selector(handleRotate:)];
rotationRecognizer.delegate = self;
;
UIPinchGestureRecognizer * pinchRecognizer = [ initWithTarget:self action:@selector(handlePinch:)];
pinchRecognizer.delegate = self;
;
;
}
}
</code></pre>
<p>我猜我进行转换的方式是错误的，因为当我将 <code>CGAffineTransformMakeRotation</code> 指令放在 <code>CGAffineTransformScale</code> 之后而不是减小大小时，它会增加它。</p >
<p>我哪里做错了？</p>
<p>编辑:handleRotate 的代码</p>
<pre><code>- (void)handleRotate:(UIRotationGestureRecognizer *)recognizer {
recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform, recognizer.rotation);
ImageView *imageView = recognizer.view;
CGFloat radians = atan2f(imageView.transform.b, imageView.transform.a);
favorite.rotation = radians;
recognizer.rotation = 0;
}
</code></pre></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>首先，你需要让你的 ViewController 实现 UIGestureRecognizerDelegate。</p>
<p><strong>SWIFT 3:-</strong></p>
<pre><code>func setUpGestures () {
let panGesture = UIPanGestureRecognizer(target: self, action:#selector(self.handlePanGesture(gesture:)))
self.imageView.addGestureRecognizer(panGesture)
let rotationGesture = UIRotationGestureRecognizer(target: self, action:#selector(self.handleRotationGesture(gesture:)))
self.imageView.addGestureRecognizer(rotationGesture)
let pinchGesture = UIPinchGestureRecognizer(target: self, action:#selector(self.handlePinchGesture(gesture:)))
self.imageView.addGestureRecognizer(pinchGesture)
}
func handlePinchGesture(gesture: UIPinchGestureRecognizer) {
if gesture.state == UIGestureRecognizerState.began || gesture.state == UIGestureRecognizerState.changed{
//print("UIPinchGestureRecognizer")
gesture.view?.transform = (gesture.view?.transform)!.scaledBy(x: gesture.scale, y: gesture.scale)
gesture.scale = 1.0
}
}
func handleRotationGesture(gesture: UIRotationGestureRecognizer) {
if gesture.state == UIGestureRecognizerState.began || gesture.state == UIGestureRecognizerState.changed{
//print("UIRotationGestureRecognizer")
gesture.view?.transform = (gesture.view?.transform)!.rotated(by: gesture.rotation)
gesture.rotation = 0
}
}
func handlePanGesture(gesture: UIPanGestureRecognizer) {
if gesture.state == UIGestureRecognizerState.began || gesture.state == UIGestureRecognizerState.changed{
//print("UIPanGestureRecognizer")
let translation = gesture.translation(in: view)
gesture.view?.transform = (gesture.view?.transform)!.translatedBy(x: translation.x, y: translation.y)
gesture.setTranslation(CGPoint(x: 0, y: 0), in: view)
}
}
</code></pre>
<p>希望，这就是您要找的。任何问题都可以回复我。 :)</p></p>
<p style="font-size: 20px;">关于ios - 如何正确拖放、旋转和缩放 UIView？，我们在Stack Overflow上找到一个类似的问题：
<a href="https://stackoverflow.com/questions/32538629/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/32538629/
</a>
</p>
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