CGGradient2

CGContextRef ctx = UIGraphicsGetCurrentContext();
 
 CGContextSaveGState(ctx);
 CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
 CGFloat colors [] = {		
 0.7,0.0,0.0,1.0,
 1.0,0.0,0.0,1.0
 } ;
 
 CGFloat locations[] = {0.5,0.0};
 CGGradientRef gradient = CGGradientCreateWithColorComponents(colorspace, colors, locations, 2);
 CGColorSpaceRelease(colorspace);
 CGContextAddRect(ctx, rect);
 CGContextDrawLinearGradient(ctx, gradient, CGPointMake(CGRectGetMidX(rect), CGRectGetMinY(rect)),
 CGPointMake(CGRectGetMidX(rect), CGRectGetMaxY(rect)),0);
 CGGradientRelease(gradient);
 CGContextRestoreGState(ctx);