+1  A: 

For shadows you can use CGContextSetShadow()

This code will draw something with a shadow:

- (void)drawTheRealThingInContext:(CGContextRef)ctx 
{   
        // calculate x, y, w, h and inset here...

    CGContextMoveToPoint(ctx, x+inset, y);
    CGContextAddLineToPoint(ctx, x+w-inset, y);
    CGContextAddArcToPoint(ctx, x+w, y, x+w, y+inset, inset);
    CGContextAddLineToPoint(ctx, x+w, y+w-inset);
    CGContextAddArcToPoint(ctx,x+w, y+w, x+w-inset, y+w, inset);
    CGContextAddLineToPoint(ctx, x+inset, y+w);
    CGContextAddArcToPoint(ctx,x, y+w, x, y+w-inset, inset);
    CGContextAddLineToPoint(ctx, x, y+inset);
    CGContextAddArcToPoint(ctx,x, y, x+inset, y, inset);    
}
- (void)drawRect:(CGRect)rect {

    CGContextRef ctx = UIGraphicsGetCurrentContext();
    CGFloat color[4];color[0] = 1.0;color[1] = 1.0;color[2] = 1.0;color[3] = 1.0;
    CGFloat scolor[4];scolor[0] = 0.4;scolor[1] = 0.4;scolor[2] = 0.4;scolor[3] = 0.8;

    CGContextSetFillColor(ctx, color);

    CGContextSaveGState(ctx);
    CGSize  myShadowOffset = CGSizeMake (3,  -3);
    CGContextSetShadow (ctx, myShadowOffset, 1);

    CGContextBeginPath(ctx);

    [self drawTheRealThingInContext:ctx];

    CGContextFillPath(ctx);
    CGContextRestoreGState(ctx);
}
Eiko
Yes, this surely works, but my problem is that I want to fill the shape with a gradient.To do so, I need to use the CGContextClip function. And once the context is clipped, it doesn't seems to draw the shadow anymore.
super_tomtom