我在向用户展示弧线然后在同一CALayer中显示矩形时遇到问题。我成功绘制了两者,但仅当圆弧相同或在矩形坐标上方绘制时才显示矩形。

知道我错过了什么吗?

-(void)drawLayer:(CALayer *)layer inContext:(CGContextRef)p_contex
{
    CGMutablePathRef thePath = CGPathCreateMutable();
    CGPathMoveToPoint(thePath,NULL,mReference.x,mReference.y);
    CGPathAddArc(thePath,NULL,
                 mReference.x, mReference.y,
                 S_RADIO, lStartAngle, lStopAngle ,
                 0);
    CGPathCloseSubpath(thePath);

    CGContextSetRGBFillColor(p_contex, lRed,lGreen,lBlue,lAlpha);
    CGContextSetRGBStrokeColor(p_contex, lRed,lGreen,lBlue,lAlpha);
    CGContextAddPath(p_contex, thePath );

    CGContextSaveGState(p_contex);
    CGContextClip(p_contex);
    CGContextDrawRadialGradient(p_contex,
                                [self buildGradientColor],
                                mReference , 5, mReference, S_RADIO, 0);

    CGContextSaveGState(p_contex);

    // release the path
    CFRelease(thePath);
    CGGradientRelease(mGradient);


    CGMutablePathRef retPath = CGPathCreateMutable();
    CGRect rect = CGRectMake(0,300, 200, 40);
    float radius = 10;
    CGRect innerRect = CGRectInset(rect, radius, radius);

    CGFloat inside_right = innerRect.origin.x + innerRect.size.width;
    CGFloat outside_right = rect.origin.x + rect.size.width;
    CGFloat inside_bottom = innerRect.origin.y + innerRect.size.height;
    CGFloat outside_bottom = rect.origin.y + rect.size.height;

    CGFloat inside_top = innerRect.origin.y;
    CGFloat outside_top = rect.origin.y;
    CGFloat outside_left = rect.origin.x;

    CGPathMoveToPoint(retPath, NULL, innerRect.origin.x, outside_top);

    CGPathAddLineToPoint(retPath, NULL, inside_right, outside_top);
    CGPathAddArcToPoint(retPath, NULL, outside_right, outside_top, outside_right, inside_top, radius);
    CGPathAddLineToPoint(retPath, NULL, outside_right, inside_bottom);
    CGPathAddArcToPoint(retPath, NULL,  outside_right, outside_bottom, inside_right, outside_bottom, radius);

    CGPathAddLineToPoint(retPath, NULL, innerRect.origin.x, outside_bottom);
    CGPathAddArcToPoint(retPath, NULL,  outside_left, outside_bottom, outside_left, inside_bottom, radius);
    CGPathAddLineToPoint(retPath, NULL, outside_left, inside_top);
    CGPathAddArcToPoint(retPath, NULL,  outside_left, outside_top, innerRect.origin.x, outside_top, radius);

    CGPathCloseSubpath(retPath);


    CGContextAddPath(p_contex, retPath );
    CGContextFillPath(p_contex);
   }

最佳答案

这里的问题是先绘制圆弧,然后绘制填充的矩形
所以弧线被绘制在这个填充矩形的后面

一种快速的解决方法是在绘制矩形之后移动弧的绘制
在绘制矩形之后移动弧的绘制

关于objective-c - 在Objective-C中的CALayer中绘制圆弧和矩形,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/10858850/

10-09 19:49
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