iOS截图

    UIGraphicsBeginImageContext(__webView.frame.size);

    [__webView.layerrenderInContext:UIGraphicsGetCurrentContext()];

    UIImage *image =UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    UIImage *viewImage = [UIImageimageWithData:UIImageJPEGRepresentation(image,0.7)];