gradient in CGContextAddArc?

I am using following code for Drawing Arc in DrawRect...I want to draw Arc only with gradient effect ...any help please?

              CG开发者_StackOverflow社区ContextSetAlpha(ctx, 0.5);
            CGContextSetRGBFillColor(ctx, color.red, color.green, color.blue, color.alpha );
            CGContextMoveToPoint(ctx, cX, cY);
            CGContextAddArc(ctx, cX, cY, radious+10, (startDeg-90)*M_PI/180.0, (endDeg-90)*M_PI/180.0, 0);
            CGContextClosePath(ctx);
            CGContextFillPath(ctx);

First create an arc then use the following code to apply gradient effect to the path,

CGGradientRef glossGradient;
CGColorSpaceRef rgbColorspace;
size_t num_locations = 2;
CGFloat locations[2] = { 0.0, 1.0 };
CGFloat components[8] = { 0.965, 0.965, 0.965, 1.0, // Start color
    0.603, 0.603, 0.603, 1.0 }; // End color

rgbColorspace = CGColorSpaceCreateDeviceRGB();
glossGradient = CGGradientCreateWithColorComponents(rgbColorspace, components, locations, num_locations);

CGRect currentBounds = self.bounds;
CGPoint topCenter = CGPointMake(CGRectGetMidX(currentBounds), 0.0f);
CGPoint midCenter = CGPointMake(CGRectGetMidX(currentBounds), CGRectGetMaxY(currentBounds));
CGContextDrawLinearGradient(UIGraphicsGetCurrentContext(), glossGradient, topCenter, midCenter, 0);

CGGradientRelease(glossGradient);
CGColorSpaceRelease(rgbColorspace);