Is there an alternative to the CALayer -renderInContext: method?

Several, but start with:

UIGetScreenImage();

      

        
        
        
      

    

Returns CGImageRef. If you are using this, note that the image is saved and you must release it.

Edit

For completeness, add a basic other way to do it:

UIWindow *aWindow = [[UIApplication sharedApplication].windows objectAtIndex:0];
UIGraphicsBeginImageContext(aWindow.frame.size);
[[aWindow layer] renderInContext:UIGraphicsGetCurrentContext()];
UIImage *screenshot = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();