小编use*_*404的帖子

$token_url = "https://graph.facebook.com/oauth/access_token?client_id="
    . $app_id . "&redirect_uri=" . urlencode($my_url) 
    . "&client_secret=" . $app_secret 
    . "&code=" . $code;

什么应该是redirect_uri？我试过用这个

'https://graph.facebook.com/oauth/authorize?client_id='.$app_id.'&
redirect_uri='.urlencode($canvas_page).'&scope=email,read_stream,publish_stream';

但它返回时出现此错误

{
   "error": {
      "message": "Error validating verification code.",
      "type": "OAuthException"
   }
}

需要帮助,提前致谢.