Drehen Sie das Bild entsprechend der Touch ziehen in iPhone

Question

Ich möchte das Bild im oder gegen den Uhrzeigersinn drehen entsprechend dem Benutzer berühren ziehen mit seiner Geschwindigkeit. Ich denke, das kann mit etwas Mathe und Logik getan werden. Wie sieht ein Codebeispiel dafür aus?

Answer 1

Wenn Sie iOS 3.2 oder höher verwenden, können Sie UIRotationGestureRecognizer verwenden. Der Code würde wie folgt aussehen:

In Ihrem Setup-Methode (viewDidLoad oder init usw.):

UIRotationGestureRecognizer *rotationGesture = 
    [[UIRotationGestureRecognizer alloc] initWithTarget:self 
               action:@selector(handleRotate:)]; 
rotationGesture.delegate = self; 
[myImageView addGestureRecognizer:rotationGesture]; 
[rotationGesture release]; 

Der Event-Handler:

- (void)handleRotate:(UIRotationGestureRecognizer *)recognizer { 
    if(recognizer.state == UIGestureRecognizerStateBegan || 
    recognizer.state == UIGestureRecognizerStateChanged) 
    { 
    recognizer.view.transform = CGAffineTransformRotate(recognizer.view.transform, 
                 recognizer.rotation); 
    [recognizer setRotation:0]; 
    } 
} 

Ich habe einige weitere Beispiele für Geste Erkenner (einschließlich der oben genannten) auf github.

Answer 2

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    for (UITouch *touch in touches) 
    { 
     currentTouch=touch; 
     if (CGRectContainsPoint([self.view frame], [touch locationInView:self.ViewRotationArrow])) 
     { 
      [self transformSpinnerwithTouches:touch]; 
     } 
     else if (!CGRectContainsPoint([ViewRotationArrow frame], [touch locationInView:self.ViewRotationArrow])) { 
      [self dispatchTouchEvent:[touch view]WithTouch:touch]; 
     } 
    } 
} 

-(void)transformSpinnerwithTouches:(UITouch *)touchLocation 
{ 
    CGPoint touchLocationpoint = [touchLocation locationInView:self.view]; 
    CGPoint PrevioustouchLocationpoint = [touchLocation previousLocationInView:self.view]; 

    //Origin is the respective point. From that I am going to measure the 
    //angle of the current position with respect to the previous position .... 
    CGPoint origin; 
    origin.x=240; 
    origin.y=160; 
    //NSLog(@"currentTouch Touch In Location In View:%F %F\n",touchLocationpoint.x,touchLocationpoint.y); 
    //NSLog(@"currentTouch Touch previous Location In View:%F %F\n",PrevioustouchLocationpoint.x,PrevioustouchLocationpoint.y); 
    CGPoint previousDifference = [self vectorFromPoint:origin toPoint:PrevioustouchLocationpoint]; 
    CGAffineTransform newTransform =CGAffineTransformScale(ViewRotationArrow.transform, 1, 1); 
    CGFloat previousRotation = atan2(previousDifference.y, previousDifference.x); 
    CGPoint currentDifference = [self vectorFromPoint:origin toPoint:touchLocationpoint]; 
    CGFloat currentRotation = atan2(currentDifference.y, currentDifference.x); 
    CGFloat newAngle = currentRotation- previousRotation; 
    NSLog(@"currentRotation of x %F previousRotation %F\n",currentRotation,previousRotation); 
    NSLog(@"Angle:%F\n",(temp1*180)/M_PI); 
    temp1=temp1+newAngle; 
    //NSLog(@"Angle:%F\n",(temp1*180)/M_PI); 
    newTransform = CGAffineTransformRotate(newTransform, newAngle); 
    [self animateView:ViewRotationArrow toPosition:newTransform]; 
} 

-(CGPoint)vectorFromPoint:(CGPoint)firstPoint toPoint:(CGPoint)secondPoint 
{ 
     CGPoint result; 
     CGFloat x = secondPoint.x-firstPoint.x; 
     CGFloat y = secondPoint.y-firstPoint.y; 
     result = CGPointMake(x, y); 
     return result; 
} 



-(void)animateView:(UIView *)theView toPosition:(CGAffineTransform) newTransform 
{ 
    //animating the rotator arrow... 
    [UIView setAnimationsEnabled:YES]; 
    [UIView beginAnimations:nil context:NULL]; 
    [UIView setAnimationCurve:UIViewAnimationCurveLinear]; 
    [UIView setAnimationBeginsFromCurrentState:YES]; 
    [UIView setAnimationDuration:0.0750]; 
    ViewRotationArrow.transform = newTransform; 
    [UIView commitAnimations]; 
} 

Answer 3

-(void)rotateView 
{ 

    //shape of eclipse 

    CAShapeLayer* circle = [[CAShapeLayer alloc] init]; 
    CGMutablePathRef path = CGPathCreateMutable(); 
    CGRect ViewRect = CGRectMake(self.view.bounds.size.width/2.8, (self.view.bounds.size.height-self.view.bounds.size.width/2)/2, self.view.bounds.size.width/4, self.view.bounds.size.width/2); 
    float midX = CGRectGetMidX(ViewRect); 
    float midY = CGRectGetMidY(ViewRect); 
    CGAffineTransform t = CGAffineTransformConcat(
                CGAffineTransformConcat(
                      CGAffineTransformMakeTranslation(-midX, -midY), 
                      CGAffineTransformMakeRotation(-1.57079633/0.99)), 
                CGAffineTransformMakeTranslation(midX, midY)); 
    CGPathAddEllipseInRect(path, &t, ViewRect); 
    circle.path = path; 
    circle.frame = self.view.bounds; 
    circle.fillColor = [UIColor clearColor].CGColor; 
    circle.strokeColor = [UIColor greenColor].CGColor; 
    circle.lineWidth = 3.0f; 
    [self.view.layer addSublayer:circle]; 

    CABasicAnimation* animation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"]; 
    animation.duration = 0.0f; 
    animation.fromValue = [NSNumber numberWithFloat:0.0f]; 
    animation.toValue = [NSNumber numberWithFloat:1.0f]; 
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]; 
    [circle addAnimation:animation forKey:@"strokeEnd"]; 


    // rotateView red color 


    testView=[[UIView alloc]init]; 
    testView.frame=CGRectMake(0, 0, 20, 20); 
    testView.backgroundColor=[UIColor redColor]; 
    testView.userInteractionEnabled=YES; 
    testView.center=CGPathGetCurrentPoint(path); 
    testView.transform = CGAffineTransformMakeRotation(1.57079633); 
    [testView sizeToFit]; 
    [self.view.layer addSublayer:testView.layer]; 


    // view Animation 

    CAKeyframeAnimation* ViewAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"]; 
    ViewAnimation.duration = 15.0f; 
    ViewAnimation.path = path; 
    ViewAnimation.rotationMode = kCAAnimationRotateAuto; 
    ViewAnimation.calculationMode = kCAAnimationCubicPaced; 
    //ViewAnimation.removedOnCompletion = NO; 
    [testView.layer addAnimation:ViewAnimation forKey:@"position"]; 

}