Make Background of UIView a Gradient Without Sub Classing

Question

Is there a way to make the background of a UIView a gradient without subclassing it? I'd rather not use an image file to accomplish this either. It just seems obtuse to have to subclass UIView just to draw a gradient for the background.

Answer 1

You can use +[UIColor colorWithPatternImage:] to produce a patterned background. Example (bring your own CGGradient):

// Allocate bitmap context
CGContextRef bitmapContext = CGBitmapContextCreate(NULL, 320, 480, 8, 4 * 320, CGColorSpaceCreateDeviceRGB(), kCGImageAlphaNoneSkipFirst);
// Draw Gradient Here
CGContextDrawLinearGradient(bitmapContext, myGradient, CGPointMake(0.0f, 0.0f), CGPointMake(320.0f, 480.0f), );
// Create a CGImage from context
CGImageRef cgImage = CGBitmapContextCreateImage(bitmapContext);
// Create a UIImage from CGImage
UIImage *uiImage = [UIImage imageWithCGImage:cgImage];
// Release the CGImage
CGImageRelease(cgImage);
// Release the bitmap context
CGContextRelease(bitmapContext);
// Create the patterned UIColor and set as background color
[targetView setBackgroundColor:[UIColor colorWithPatternImage:image]];

It will probably be simpler to just create a UIView subclass though. It will use less memory as well.

Answer 2

I agree with rpetrich, it would be cleaner to just do the UIView subclass. For an example of how to do this, see my response in this question. If you wanted, you could create a generic gradient UIView subclass and simply place that behind the views you want to have gradient backgrounds.

Answer 3

As of iPhone SDK 3.0, there's a much simpler solution that relies on the new CAGradientLayer and doesn't require subclassing or images.