?- (void)drawRoundRect : (CGContextRef)context {
// Drawing with a white stroke color CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 1.0); // And draw with a blue fill color CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1.0); // Draw them with a 2.0 stroke width so they are a bit more visible. CGContextSetLineWidth(context, 2.0); CGRect rrect = CGRectMake(210.0, 90.0, 60.0, 60.0); CGFloat radius = 10.0; // NOTE: At this point you may want to verify that your radius is no more than half // the width and height of your rectangle, as this technique degenerates for those cases. // In order to draw a rounded rectangle, we will take advantage of the fact that // CGContextAddArcToPoint will draw straight lines past the start and end of the arc // in order to create the path from the current position and the destination position. // In order to create the 4 arcs correctly, we need to know the min, mid and max positions // on the x and y lengths of the given rectangle. CGFloat minx = CGRectGetMinX(rrect), midx = CGRectGetMidX(rrect), maxx = CGRectGetMaxX(rrect); CGFloat miny = CGRectGetMinY(rrect), midy = CGRectGetMidY(rrect), maxy = CGRectGetMaxY(rrect); // Next, we will go around the rectangle in the order given by the figure below. // minx midx maxx // miny 2 3 4 // midy 1 9 5 // maxy 8 7 6 // Which gives us a coincident start and end point, which is incidental to this technique, but still doesn't // form a closed path, so we still need to close the path to connect the ends correctly. // Thus we start by moving to point 1, then adding arcs through each pair of points that follows. // You could use a similar tecgnique to create any shape with rounded corners. // Start at 1 CGContextMoveToPoint(context, minx, midy); // Add an arc through 2 to 3 CGContextAddArcToPoint(context, minx, miny, midx, miny, radius); // Add an arc through 4 to 5 CGContextAddArcToPoint(context, maxx, miny, maxx, midy, radius); // Add an arc through 6 to 7 CGContextAddArcToPoint(context, maxx, maxy, midx, maxy, radius); // Add an arc through 8 to 9 CGContextAddArcToPoint(context, minx, maxy, minx, midy, radius); // Close the path CGContextClosePath(context); // Fill & stroke the path CGContextDrawPath(context, kCGPathFillStroke);}