iPhone iOS how to render a screenshot with a different resolution or scale?

Question

I'm trying to save a screenshot of my iPhone screen, but the result is coming out at 1x scale.

For example a 320x480 pixels screenshot is 320x480 pixels, when displayed on a retina display, it looks fuzzy. But if I take a screenshot with the home screen and the power button, the resulting image is 640x960 and looks perfect on a retina display. How can I take screenshots of the screen taking into account the scale factor of the screen?

Thank you!

Answer 1

Try This:

if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)])
        UIGraphicsBeginImageContextWithOptions(self.window.bounds.size, NO, [UIScreen mainScreen].scale);
    else
        UIGraphicsBeginImageContext(self.window.bounds.size);

    [self.window.layer renderInContext:UIGraphicsGetCurrentContext()];
        UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        NSData * data = UIImagePNGRepresentation(image);
        [data writeToFile:@"foo.png" atomically:YES];