drawRect的代码如下:
CGMutablePathRef pathRef = CGPathCreateMutable();
CGPathMoveToPoint(pathRef, NULL, 0, 220);
CGPathAddLineToPoint(pathRef, NULL, rect.size.width, 220);
CGPathAddLineToPoint(pathRef, NULL, rect.size.width, rect.size.height);
CGPathAddLineToPoint(pathRef, NULL, 0, rect.size.height);
CGPathCloseSubpath(pathRef);
如何添加黑色的边框和圆角?