How can I make an UIImage programmatically?

Question

This isn\'t what you probably thought it was to begin with. I know how to use UIImage\'s, but I now need to know how to create a \"blank\" UIImage using:

CGRect sc

Answer 1

If you want to draw just an empty image, you could use UIKit UIImageBeginImageContextWithOptions: method.

    UIGraphicsBeginImageContext(CGSizeMake(width, height));
    CGContextAddRect(UIGraphicsGetCurrentContext(), CGRectMake(0, 0, width, height)); // this may not be necessary
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

The code above assumes that you draw a image with a size of width x height. It adds rectangle into the graphics context, but it may not be necessary. Try it yourself. This is the way to go. :)

Or, if you want to create a snapshot of your current view you would type code like;

 UIGraphicsBeginImageContext(CGSizeMake(self.view.size.width, self.view.size.height));
    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

Don't forget to include Quartz library if you use layer.