HttpWebRequest StreamReader 失败，出现 utf-8 is not a supported encoding name 错误

Question

我正在使用以下代码从网页中检索数据。它适用于大多数页面，但在某些页面中会引发错误，如下所示；

    String url = @"https://m.facebook.com";
    try
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        if (response.StatusCode == HttpStatusCode.OK)
        {
            Stream receiveStream = response.GetResponseStream();
            StreamReader readStream = null;
            if (response.CharacterSet == null)
                readStream = new StreamReader(receiveStream);
            else
                readStream = new StreamReader(receiveStream, Encoding.GetEncoding(response.CharacterSet));
            string data = readStream.ReadToEnd();
            response.Close();
            readStream.Close();

        }
    }
    catch (Exception ex)
    { 
    // utf-8 is not a supported encoding name error
    }

如何解决这个问题？这里的其他帖子并没有解决我的问题。

Answer 1

这里的错误是response.CharacterSet 正在返回"utf-8"。方法Encoding.GetEncoding 不知道这意味着什么，因为文本周围的引号。所以你必须把它们去掉。

替换这一行：

readStream = new StreamReader(receiveStream, 
    Encoding.GetEncoding(response.CharacterSet));

用这个：

readStream = new StreamReader(receiveStream, 
    Encoding.GetEncoding(response.CharacterSet.Replace("\"", string.Empty)));