Take screenshots on ios

ios_take_screenshot

// http://developer.apple.com/library/ios/#qa/qa1703/_index.html#//apple_ref/doc/uid/DTS40010193
- (UIImage*)screenshot 
{
    CGSize imageSize = [[UIScreen mainScreen] bounds].size;
    if (NULL != UIGraphicsBeginImageContextWithOptions)
        UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);
    else
        UIGraphicsBeginImageContext(imageSize);

    CGContextRef context = UIGraphicsGetCurrentContext();

    for (UIWindow *window in [[UIApplication sharedApplication] windows]) 
    {
        if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen])
        {
            CGContextSaveGState(context);
            CGContextTranslateCTM(context, [window center].x, [window center].y);
            CGContextConcatCTM(context, [window transform]);
            CGContextTranslateCTM(context,
                                  -[window bounds].size.width * [[window layer] anchorPoint].x,
                                  -[window bounds].size.height * [[window layer] anchorPoint].y);

            [[window layer] renderInContext:context];

            CGContextRestoreGState(context);
        }
    }

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return image;
}