[英]How to drag and drop, rotate and zoom correctly a UIView?
在我的 iOS 应用程序中,我使用 UITouchGestureRecognizer 来拖放、缩放和旋转 UIImageView。 我还将信息存储在 ImageView 的最后一个位置,以便在应用程序重新启动时检索它。
这在 iOS7 上运行良好,但我最近开始在 iOS8 上进行测试,但我遇到了一些问题,尤其是在缩放方面。 每当 imageview 的旋转参数中的角度为非 0 时,缩放不会像预期的那样工作并减小图像的大小。
我不明白为什么操作系统会改变,这是我的代码:
-(void) viewDidAppear:(BOOL)animated{
[super viewDidAppear:YES];
[self loadAllImages];
for (GIFavorite *favorite in self.favorites){
UIImage *image = favorite.image;
ImageView *imageView = [[ImageView alloc] 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 = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)];
panRecognizer.delegate = self;
[imageView addGestureRecognizer:panRecognizer];
UIRotationGestureRecognizer * rotationRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(handleRotate:)];
rotationRecognizer.delegate = self;
[imageView addGestureRecognizer:rotationRecognizer];
UIPinchGestureRecognizer * pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinch:)];
pinchRecognizer.delegate = self;
[imageView addGestureRecognizer:pinchRecognizer];
[self.view addSubview:imageView];
}
}
我想我做变换的方式是错误的,因为当我把CGAffineTransformMakeRotation
指令后CGAffineTransformScale
,而不是降低它增加它的大小。
我哪里做错了?
编辑:handleRotate 的代码
- (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;
}
首先,你需要让你的视图控制器实现 UIGestureRecognizerDelegate。
然后将手势识别器添加到您的 UIView(我看到您已经这样做了,但只需将其再次放在这里即可将解决方案集中在一个地方)。
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)];
panGesture.delegate = self;
UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(handleRotate:)];
rotationGesture.delegate = self;
UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinch:)];
pinchGesture.delegate = self;
[yourView addGestureRecognizer:panGesture];
[yourView addGestureRecognizer:rotationGesture];
[yourView addGestureRecognizer:pinchGesture];
然后,这就是你的handle...
方法应该是:
- (void)handlePinch:(UIPinchGestureRecognizer *)pinchRecognizer
{
UIGestureRecognizerState state = [pinchRecognizer state];
if (state == UIGestureRecognizerStateBegan || state == UIGestureRecognizerStateChanged)
{
CGFloat scale = [pinchRecognizer scale];
[pinchRecognizer.view setTransform:CGAffineTransformScale(pinchRecognizer.view.transform, scale, scale)];
[pinchRecognizer setScale:1.0];
}
}
- (void)handleRotate:(UIRotationGestureRecognizer *)rotationGestureRecognizer {
UIGestureRecognizerState state = [rotationGestureRecognizer state];
if (state == UIGestureRecognizerStateBegan || state == UIGestureRecognizerStateChanged)
{
CGFloat rotation = [rotationGestureRecognizer rotation];
[rotationGestureRecognizer.view setTransform:CGAffineTransformRotate(rotationGestureRecognizer.view.transform, rotation)];
[rotationGestureRecognizer setRotation:0];
}
}
- (void)handlePan:(UIPanGestureRecognizer *)panRecognizer {
UIGestureRecognizerState state = [panRecognizer state];
if (state == UIGestureRecognizerStateBegan || state == UIGestureRecognizerStateChanged)
{
CGPoint translation = [panRecognizer translationInView:panRecognizer.view];
[panRecognizer.view setTransform:CGAffineTransformTranslate(panRecognizer.view.transform, translation.x, translation.y)];
[panRecognizer setTranslation:CGPointZero inView:panRecognizer.view];
}
}
这是它的外观:
首先,你需要让你的视图控制器实现 UIGestureRecognizerDelegate。
SWIFT 3 :-
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)
}
}
希望,这就是你要找的。 有任何问题都可以回复我。 :)
尝试做这些..
首先在你的 ViewControllers .h 中做这些..
@interface RotationViewController : UIViewController<UIGestureRecognizerDelegate>//Add these..
{
UIView *testView;
}
现在在您的 ViewController 的 .m 文件中执行这些操作。
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
testView=[[UIView alloc]initWithFrame:CGRectMake(100, 100, 160, 160)];
UIImageView * imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 160, 160)];
[imageView setImage:[UIImage imageNamed:@"ImageName.png"]];
[imageView setContentMode:UIViewContentModeScaleAspectFit];
[testView addSubview:imageView];
[self.view addSubview:testView];
UIRotationGestureRecognizer *rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(handleRotate:)];
[testView addGestureRecognizer:rotationGestureRecognizer];
}
-(void) handleRotate:(UIRotationGestureRecognizer *)rotationGestureRecognizer
{
testView.transform = CGAffineTransformRotate(testView.transform, rotationGestureRecognizer.rotation);
rotationGestureRecognizer.rotation = 0.0;
}
我希望它有帮助..
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