ピンチズームは、iOSのiPadで最も左隅に画像をシフトしていますか？

Question

私はiOSで画像を持っています。私は左上隅にシフトした画像をピンチするときに、画像にピンチジェスチャーを追加しました。私も画像にパンジェスチャーを追加しました。画像が拡大されると、その目的のために画像をあらゆる方向にスクロールしています。画像にパンジェスチャを追加しました。

私のコードは次のとおりです。

-(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; 

} 

パンジェスチャー

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

ここでは、可能な解決策です。

•このクラスはイメージだけでなく、どのようなビューも操作できるため、zoom_imageの名前をcontentViewで変更しました。

私はバインドのテストを除去し、スケールは（0.01から10.0）にも聞かせてきた•

ピンチ•3本の指まで処理し、またパンとして機能します。ピンチを中断することなくタッチの回数を変更することができます。

あり改善するための多くのものはまだあるが、主な原則はここにある:)

インタフェース（そうminScale、MaxScaleの、minMarginなどのプロパティが追加されることはまだある - なぜ委任）

@interface PinchViewController : UIViewController 

@property(nonatomic,strong) IBOutlet UIView* contentView; 

@end 

実装

@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 

は、WILホープ私は助け:)乾杯