iphone中drawRect画图形

Question

我的代码如下：

- (void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGFloat commentHeight = 0;


        CGSize commentSize = [self.highlightItem_.comment sizeWithFont:[UIFont fontWithName:kProximaNova size:18] constrainedToSize:CGSizeMake(rect.size.width, CGFLOAT_MAX) lineBreakMode:NSLineBreakByWordWrapping];
        commentHeight = commentSize.height + 50;

        CGContextSetRGBStrokeColor(context, 68/255.f, 68/255.f, 68/255.f, 1.0);
        CGContextSetRGBFillColor(context, 68/255.f, 68/255.f, 68/255.f, 1.0);
        CGContextSetLineJoin(context, kCGLineCapSquare);
        CGContextSetLineWidth(context, 1.0);

        CGMutablePathRef pathRef = CGPathCreateMutable();

        CGPathMoveToPoint(pathRef, NULL, 0, rect.size.height - commentHeight);
        CGPathAddLineToPoint(pathRef, NULL, 20, rect.size.height - commentHeight);
        CGPathAddLineToPoint(pathRef, NULL, 25, rect.size.height - commentHeight - 10);
        CGPathAddLineToPoint(pathRef, NULL, 30, rect.size.height - commentHeight);
        CGPathAddLineToPoint(pathRef, NULL, rect.size.width, rect.size.height - commentHeight);
        CGPathAddLineToPoint(pathRef, NULL, rect.size.width, rect.size.height);
        CGPathAddLineToPoint(pathRef, NULL, 0, rect.size.height);
        CGPathCloseSubpath(pathRef);

        CGContextAddPath(context, pathRef);
        //CGContextFillPath(context);
        CGContextDrawPath(context, kCGPathFill);


        CGPathRelease(pathRef);
}

但是没有画出预期的图片，不知道为什么？请高手指教，谢谢

Answer 1

可以学习一下，这个重绘的机制：
http://blog.csdn.net/fww330666557/article/details/8647608