Prise Zoom verschiebt Bild auf die meisten linken Ecke auf dem iPad in iOS?

Question

Ich habe ein Bild in iOS. Ich habe Pinch-Geste auf dem Bild hinzugefügt, wenn ich das Bild klemmen, das es nach oben links Ecke verschoben hat. Ich habe auch Schwenkgeste auf Bild hinzugefügt. Wenn ein Bild gezoomt wird, scrolle ich das Bild zu diesem Zweck in jede Richtung und habe die Schwenkbewegung in das Bild eingefügt.

Mein Code ist:

-(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; 

} 

Pan Geste

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

Hier ist eine mögliche Lösung.

• Ich habe Ihre zoom_image durch contentView umbenannt, da diese Klasse jede Ansicht manipulieren kann, nicht nur Bilder.

• ich die gebundenen Tests entfernt haben, und lassen Sie die Waage werden in (0,01 bis 10,0)

• Die Prise drei Finger Griff nach oben, und fungiert auch als pan. Die Anzahl der Berührungen kann geändert werden, ohne den Druck zu unterbrechen.

Es gibt noch viele Dinge zu verbessern, aber das Hauptprinzip ist hier :)

Schnittstelle (Eigenschaften wie MINSCALE, maxscale, minmargin und so werden noch hinzugefügt werden - warum nicht ein Delegierter)

@interface PinchViewController : UIViewController 

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

@end 

Implementierung

@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 

Hoffe, es wil l Hilfe :) Prost