iOS: Draw gradient fill

CustomView_drawGradient.m

-(void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrnetContext();
    CGGradientRef gradient = [self gradient];
    CGPoint startPoint = CGPointMake(CGRectGetMidX(self.bounds), 0.0);
    CGPoint endPoint = CGPointMake(CGRectGetMidX(self.bounds), CGRectGetMaxY(self.bounds));
    CGContextDrawLinearGradient(context, gradient, startPoint, endPoint);
}

-(CGGradientRef)gradient
{
    if (nil == _gradient)
    {
        CGFloat colors[6] = { 
            138.0f / 255.0f, 1.0f,
            162.0f / 255.0f, 1.0f,
            206.0f / 255.0f, 1.0f};
        CGFloat locations[3] = { 0.05f, 0.45f, 0.95f };
        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
        _gradient = CGGradientCreateWithColorComponents(colorSpace, colors, locations, 3);
        CGColorSpaceRelease(colorSpace);
    }
    return _gradient;
}