iOS Draw Rectagle with curved ends

问题

Imagine a long rectangle (maybe with size 200x20). All sides have straight edges. In my iOS app, this is easy for me to draw:

CGContextFillRect(context, CGRectMake(xLoc, yLoc, 200, 20));

Now what if I wanted the shorter ends (on the left and right side of the rectangle) to be slightly curved, rather than straight edges. What would the code look like to do this?

(Note that I am relatively inexperienced with CGContext drawing)

回答1:

Something like this (untested, so beware of bugs!):

- (void)drawRect:(CGRect)rect {
 CGContextRef context = UIGraphicsGetCurrentContext();
 CGContextSetStrokeColorWithColor(context, [[UIColor blackColor] CGColor]);
 CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1.0);

 CGRect rrect = CGRectMake(CGRectGetMinX(rect), CGRectGetMinY(rect), CGRectGetWidth(rect)-30, CGRectGetHeight(rect)-30);
 CGFloat radius = 0.5f;

 CGFloat minx = CGRectGetMinX(rrect), midx = CGRectGetMidX(rrect), maxx = CGRectGetMaxX(rrect);
 CGFloat miny = CGRectGetMinY(rrect), midy = CGRectGetMidY(rrect), maxy = CGRectGetMaxY(rrect);

 CGContextMoveToPoint(context, minx, midy);
 CGContextAddArcToPoint(context, minx, miny, midx, miny, radius);
 CGContextAddArcToPoint(context, maxx, miny, maxx, midy, radius);
 CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius);
 CGContextAddArcToPoint(context, minx, maxy, minx, midy, radius);
 CGContextClosePath(context);
 CGContextDrawPath(context, kCGPathFillStroke);
}

回答2:

You may find Jeff LaMarche's RoundedRectView class useful, whether to use instances of directly or even to see how he makes them:

http://iphonedevelopment.blogspot.com/2008/11/creating-transparent-uiviews-rounded.html

来源：https://stackoverflow.com/questions/6553804/ios-draw-rectagle-with-curved-ends