Creating background gradients for a view programmatically? How?

Question

I have a small view with a few buttons on it. I want to make this small views background a black gradient identical to the gradient when you set your UINavigation bar to Black Opaque?

Is this possible programmatically or do I need to try my best at Photoshop to copy it? :)

Possible dupe of http://stackoverflow.com/questions/422066/gradients-on-uiview-and-uilabels-on-iphone/422208#422208 — Wayne Hartman, Feb 12 '11 at 18:03

score 3 · Accepted Answer · edited Dec 27 '13 at 17:25

Simple override drawRect message for UIView and draw background:

- (void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrentContext();
    GContextDrawLinearGradient(context, self.gradientLayer, CGPointMake(0.0, 0.0),
                            CGPointMake(0.0, self.frame.size.height), kCGGradientDrawsBeforeStartLocation);
}

For creating and caching gradient use this snippet (color components you should use your own).

- (CGGradientRef)gradientLayer
{
    if (_gradientLayer == nil)
    {
        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); 
        CGFloat locations[] = { 0.0, 1.0 };
        CGFloat colors[] = { 0.0 / 255.0, 0.0 / 255.0, 48.0 / 255.0, 1.00, 26.0 / 255.0, 48.0 / 255.0, 89.0 / 255.0, 1.00 };

        _gradientLayer = CGGradientCreateWithColorComponents(colorSpace, colors, locations, sizeof(colors) / (sizeof(colors[0]) * 4));
        CGColorSpaceRelease(colorSpace);
    }
    return _gradientLayer;
}

And of course don't forget release your gradient into dealloc.

Creating background gradients for a view programmatically? How?

1 Answers1