1 UIGraphicsBeginImageContextWithOptions(CGSizeMake(200, 200),NO ,[UIScreen mainScreen].scale);
 2 CGContextRef context = UIGraphicsGetCurrentContext();
 3 size_t locations = 2;
 4 CGFloat location[2] ={0.0,1.0};
 5 CGFloat components[8] = {1.0,0.5,0.4,1.0,
 6                      0.8,0.8,0.3,1.0};
 7 CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
 8 CGGradientRef mygradient  = CGGradientCreateWithColorComponents(colorSpace, components, location, locations);
 9 CGContextDrawLinearGradient (context,mygradient,CGPointMake(0.0, 0.0),CGPointMake(200.0, 200.0), 0);
10 UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
11 UIGraphicsEndImageContext();

//CGContextDrawLinearGradient (context,mygradient,CGPointMake(0.0, 0.0),CGPointMake(200.0, 200.0), 0);
CGContextDrawRadialGradient (context,mygradient,CGPointMake(10.0, 10.0),10.0f,CGPointMake(150.0, 150.0),50.0f,kCGGradientDrawsBeforeStartLocation & kCGGradientDrawsAfterEndLocation);

CGContextDrawRadialGradient (context,mygradient,CGPointMake(100.0, 100.0),0.0f,CGPointMake(100.0, 100.0),100.0f,kCGGradientDrawsBeforeStartLocation & kCGGradientDrawsAfterEndLocation);

size_t locations = 3;
CGFloat location[3] ={0.0,0.5,1.0};
CGFloat components[12] = {1.0,0.5,0.4,1.0,
                            0.5,0.5,0.5,1.0,
                            0.8,0.8,0.3,1.0};

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code

        self.layer.cornerRadius = 8.0f;
        self.layer.masksToBounds = YES;
        self.layer.borderWidth = 1.0f;
        self.layer.borderColor = [UIColor colorWithWhite:0.5f alpha:0.2f].CGColor;
    }
    return self;
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    CGContextRef ref = UIGraphicsGetCurrentContext();
    CGFloat locations[5] = {0.0,0.5,0.5,0.8,1.0};
    CFArrayRef colors = (__bridge CFArrayRef) @[(id)[UIColor colorWithWhite:1.0f alpha:0.6f].CGColor,
                            (id)[UIColor colorWithWhite:0.9f alpha:0.3f].CGColor,
                            (id)[UIColor colorWithWhite:0.75f alpha:0.2f].CGColor,
                            (id)[UIColor colorWithWhite:0.4f alpha:0.3f].CGColor,
                            (id)[UIColor colorWithWhite:1.0f alpha:0.2f].CGColor];
    CGColorSpaceRef colorSpc = CGColorSpaceCreateDeviceRGB();
    CGGradientRef gradient = CGGradientCreateWithColors(colorSpc, colors, locations);
    CGContextDrawLinearGradient(ref, gradient, CGPointMake(0.5, 0.0), CGPointMake(0.5, rect.size.height), kCGGradientDrawsAfterEndLocation);
    CGColorSpaceRelease(colorSpc);
    CGGradientRelease(gradient);
}