How to draw a gradient line (fading in/out) with Core Graphics/iPhone?

Question

I know how to draw a simple line:

CGContextSetRGBStrokeColor(context, 1.0, 1.0, 1.0, 1.0);
CGContextMoveToPoint(context, x, y);
CGContextAddLineToPoint(conte         


        

Answer 1

After several tries I'm now sure that gradients doesn't affect strokes, so I think it's impossible to draw gradient lines with CGContextStrokePath(). For horizontal and vertical lines the solution is to use CGContextAddRect() instead, which fortunately is what I need. I replaced

CGContextMoveToPoint(context, x, y);
CGContextAddLineToPoint(context, x2, y2);
CGContextStrokePath(context);

with

CGContextSaveGState(context);
CGContextAddRect(context, CGRectMake(x, y, width, height));
CGContextClip(context);
CGContextDrawLinearGradient (context, gradient, startPoint, endPoint, 0);
CGContextRestoreGState(context);

and everything works fine. Thanks to Brad Larson for the crucial hint.