捏放大图像移动到iPad的最左上angular在iOS？

我在iOS中有一个图像。 当我捏的图像移到左上angular时，我在图像上添加了捏手势。 我也在图像上添加了平移手势。 当图像放大，然后我滚动图像在每个方向为此目的我已经添加了平移手势的图像。

我的代码是：

-(void)viewDidLoad { UIPinchGestureRecognizer *pinch=[[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(handlePinch:)]; [self.zoom_image addGestureRecognizer:pinch]; panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(moveImage:)]; [panGesture setMinimumNumberOfTouches:1]; [panGesture setMaximumNumberOfTouches:1]; [self.zoom_image addGestureRecognizer:panGesture]; img_center_x = self.zoom_image.center.x; img_center_y = self.zoom_image.center.y; } -(void)handlePinch:(UIPinchGestureRecognizer*)sender { NSLog(@"latscale = %f",mLastScale); mCurrentScale += [sender scale] - mLastScale; mLastScale = [sender scale]; NSLog(@"before ceneter x %f",img_center_x); NSLog(@"before ceneter x %f",img_center_y); CGPoint img_center = CGPointMake(img_center_x, img_center_y); self.zoom_image.center = img_center; if (sender.state == UIGestureRecognizerStateEnded) { mLastScale = 1.0; } if(mCurrentScale<1.0) { mCurrentScale=1.0; } if(mCurrentScale>3.0) { mCurrentScale=3.0; } CGAffineTransform currentTransform = CGAffineTransformIdentity; CGAffineTransform newTransform = CGAffineTransformScale(currentTransform,mCurrentScale, mCurrentScale); self.zoom_image.transform = newTransform; } 

平底锅手势

  UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(moveImage:)]; [panGesture setMinimumNumberOfTouches:1]; [panGesture setMaximumNumberOfTouches:1]; [self.zoom_image addGestureRecognizer:panGesture]; move image: - (void)moveImage:(UIPanGestureRecognizer *)recognizer { CGPoint translation = [recognizer translationInView:self.zoom_image]; CGPoint location = [recognizer locationInView:self.view]; CGPoint initial=CGPointZero; NSLog(@"%f\n%f",translation.x,translation.y); NSLog(@"%f",self.zoom_image.frame.origin.y); CGPoint finalpoint = CGPointMake(self.zoom_image.center.x + translation.x, self.zoom_image.center.y+ translation.y); NSLog(@"%f",finalpoint.y); //limit the boundary if(recognizer.state==UIGestureRecognizerStateChanged) { if ((self.zoom_image.frame.origin.x>0 && translation.x > 0) || (self.zoom_image.frame.origin.x + self.zoom_image.frame.size.width<=self.view.frame.size.width && translation.x < 0)) finalpoint.x = self.zoom_image.center.x; if ((self.zoom_image.frame.origin.y>100 && translation.y > 0) || (self.zoom_image.frame.origin.y + self.zoom_image.frame.size.height<=self.view.frame.size.height && translation.y < 0)) finalpoint.y = self.zoom_image.center.y; //set final position NSLog(@"%f",finalpoint.y); self.zoom_image.center = finalpoint; [recognizer setTranslation:initial inView:self.zoom_image]; } } 

Answer 1

这是一个可能的解决scheme。

•我已经通过contentView重命名了zoom_image，因为这个类可以处理任何视图，而不仅仅是图像。

•我已经删除了绑定的testing，并让规模在（0.01 – 10.0）

•最多可以捏三个手指，也可以作为平底锅。 触摸次数可以在不中断捏的情况下进行更改。

还有很多事情要改进，但主要原则在这里:)

接口 （像minScale，maxScale，minMargin等属性仍然被添加 – 为什么不是委托）

 @interface PinchViewController : UIViewController @property(nonatomic,strong) IBOutlet UIView* contentView; @end 

履行

 @implementation PinchViewController { CGPoint translation; CGFloat scale; CGAffineTransform scaleTransform; CGAffineTransform translateTransform; CGPoint previousTranslation; CGFloat previousScale; NSUInteger previousNumTouches; } -(void)viewDidLoad { scale = 1.0f; scaleTransform = CGAffineTransformIdentity; translateTransform = CGAffineTransformIdentity; previousTranslation = CGPointZero; previousNumTouches = 0; UIPinchGestureRecognizer *pinch=[[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(handlePinch:)]; [self.view addGestureRecognizer:pinch]; UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)]; [panGesture setMinimumNumberOfTouches:1]; [panGesture setMaximumNumberOfTouches:1]; [self.view addGestureRecognizer:panGesture]; } -(void)handlePinch:(UIPinchGestureRecognizer*)recognizer { // 1 - find pinch center CGPoint mid = [self computePinchCenter:recognizer]; mid.x-= recognizer.view.bounds.size.width / 2.0f; mid.y-= recognizer.view.bounds.size.height / 2.0f; // 2 - compute deltas NSUInteger numTouches = recognizer.numberOfTouches; if ( (recognizer.state==UIGestureRecognizerStateBegan) || ( previousNumTouches != numTouches ) ) { previousScale = recognizer.scale; previousTranslation = mid; previousNumTouches = numTouches; } CGFloat deltaScale = ( recognizer.scale - previousScale ) * scale; previousScale = recognizer.scale; CGPoint deltaTranslation = CGPointMake(mid.x-previousTranslation.x, mid.y-previousTranslation.y); previousTranslation = mid; deltaTranslation.x/=scale; deltaTranslation.y/=scale; // 3 - apply scale+=deltaScale; if (scale<0.01) scale = 0.01; else if (scale>10) scale = 10; scaleTransform = CGAffineTransformMakeScale(scale, scale); [self translateBy:deltaTranslation]; NSLog(@"Translation : %.2f,%.2f - Scale Center : %.2f,%.2f - Scale : %.2f",deltaTranslation.x,deltaTranslation.y,mid.x,mid.y,scale); } - (void)handlePan:(UIPanGestureRecognizer *)recognizer { if (recognizer.state==UIGestureRecognizerStateBegan) previousTranslation = CGPointZero; CGPoint recognizerTranslation = [recognizer translationInView:self.contentView]; CGPoint deltaTranslation = CGPointMake(recognizerTranslation.x - previousTranslation.x,recognizerTranslation.y - previousTranslation.y); previousTranslation = recognizerTranslation; [self translateBy:deltaTranslation]; NSLog(@"Translation : %.2f,%.2f - Scale : %.2f",deltaTranslation.x,deltaTranslation.y,scale); } -(void)translateBy:(CGPoint)delta { translation.x+=delta.x; translation.y+=delta.y; translateTransform = CGAffineTransformMakeTranslation(translation.x,translation.y); self.contentView.transform = CGAffineTransformConcat(translateTransform,scaleTransform); } -(CGPoint)computePinchCenter:(UIPinchGestureRecognizer*)recognizer { // 1 - handle up to 3 touches NSUInteger numTouches = recognizer.numberOfTouches; if (numTouches>3) numTouches = 3; // 2 - Find fingers middle point - with (0,0) being the center of the view CGPoint pt1,pt2,pt3,mid; switch (numTouches) { case 3: pt3 = [recognizer locationOfTouch:2 inView:recognizer.view]; case 2: pt2 = [recognizer locationOfTouch:1 inView:recognizer.view]; case 1: pt1 = [recognizer locationOfTouch:0 inView:recognizer.view]; } switch (numTouches) { case 3: mid = CGPointMake( ( ( pt1.x + pt2.x ) / 2.0f + pt3.x ) / 2.0f, ( ( pt1.y + pt2.y ) / 2.0f + pt3.y ) / 2.0f ); break; case 2: mid = CGPointMake( ( pt1.x + pt2.x ) / 2.0f, ( pt1.y + pt2.y ) / 2.0f ); break; case 1: mid = CGPointMake( pt1.x, pt1.y); break; } return mid; } @end 

希望它会帮助:)干杯