iOS 앱에서 오류 페인팅

Question

메인 뷰의 하위 뷰 내부에서 UIImageView에 페인트 할 수있는 iOs 5 앱을 개발 중입니다. 선의 처음 30px를 페인트하면 획을 따라 가지 않습니다. 하지만 정말 드문 것은 ImageView의 크기를 460x320 크기의 모든 화면으로 만들면 (내부의보기보다 크기 때문에 전체 ImageView는 보이지 않지만) 괜찮습니다. 어쩌면 해결책이있을 수도 있습니다.

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { 
    mouseSwiped = NO; 
    UITouch *touch = [touches anyObject]; 

    if ([touch tapCount] == 2) { 
     drawImage.image = nil; 
     return; 
    } 

    lastPoint = [touch locationInView:self.view]; 
    lastPoint.y -= 10; 
} 

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { 
    mouseSwiped = YES; 
    UITouch *touch = [touches anyObject]; 
    CGPoint currentPoint = [touch locationInView:self.drawImage]; 
    currentPoint.y -= 10; // only for 'kCGLineCapRound' 
    UIGraphicsBeginImageContext(self.drawImage.frame.size); 

    [drawImage.image drawInRect:CGRectMake(0, 0, drawImage.frame.size.width, drawImage.frame.size.height)]; //originally self.frame.size.width, self.frame.size.height)]; 
    CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound); //kCGLineCapSquare, kCGLineCapButt, kCGLineCapRound 
    CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5); // for size 
    CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 0.0, 1.0, 0.0, 1.0); //values for R, G, B, and Alpha 
    CGContextBeginPath(UIGraphicsGetCurrentContext()); 
    CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y); 
    CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y); 
    CGContextStrokePath(UIGraphicsGetCurrentContext()); 
    drawImage.image = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 

    lastPoint = currentPoint; 

    mouseMoved++; 

    if (mouseMoved == 10) { 
     mouseMoved = 0; 
    } 
} 

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {  
    UITouch *touch = [touches anyObject]; 

    if ([touch tapCount] == 2) { 
     drawImage.image = nil; 
     return; 
    } 
    if(!mouseSwiped) { 
     //if color == green 
     UIGraphicsBeginImageContext(self.drawImage.frame.size); 
     [drawImage.image drawInRect:CGRectMake(0, 0, drawImage.frame.size.width, drawImage.frame.size.height)]; //originally self.frame.size.width, self.frame.size.height)]; 
     CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound); //kCGLineCapSquare, kCGLineCapButt, kCGLineCapRound 
     CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5); 
     CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 0.0, 1.0, 0.0, 1.0); 
     CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y); 
     CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y); 
     CGContextStrokePath(UIGraphicsGetCurrentContext()); 
     CGContextFlush(UIGraphicsGetCurrentContext()); 
     drawImage.image = UIGraphicsGetImageFromCurrentImageContext(); 
     UIGraphicsEndImageContext(); 
    } 
} 

Answer 1

문제는 첫째 touchesMoved:이 API에 의해 지연되고 있다는 점이다 : 그것은 내 코드입니다. 아무도이 문제를 아직 해결하지 못했습니다.

하지만, 단순한 실수가 http://radar.apple.com

에서 귀하의 경우 실제 문제를 버그보고를하십시오 : 당신은 서로 다른 두 touchesBegan: 및 touchesMoved:에 좌표계를 사용하고 있습니다.

touchesBegan :

lastPoint = [touch locationInView:self.view]; 
           ////////// 

는 touchesMoved :

CGPoint currentPoint = [touch locationInView:self.drawImage]; 
              ///////////////