使用 HttpWebRequest 的 C# 编码问题

Question

从 HttpWebRequest 返回字符串时，我收到的字符代码（' 和 &quote;）破坏了我的响应（显示 39; 和 uto;）：

internal static void TranslateThis(Player player, string fromLang, string toLang, string text){
    try
    {
        string translated = null;
        HttpWebRequest hwr = (HttpWebRequest)HttpWebRequest.Create("http://translate.google.com/?langpair=" + fromLang + "|" + toLang + "&text=" + text.Replace(" ", "+") + "#");
        HttpWebResponse res = (HttpWebResponse)hwr.GetResponse();
        StreamReader sr = new StreamReader(res.GetResponseStream());
        string html = sr.ReadToEnd();
        int a = html.IndexOf("onmouseout=\"this.style.backgroundColor='#fff'\">") + 47;
        int b = html.IndexOf("</span>",html.IndexOf("onmouseout=\"this.style.backgroundColor='#fff'\">") + 47);
        translated = html.Substring(a, b - a);
        if (translated.Length < (10 * text.Length)){
            if (player == Player.Console)
            {
                player.ParseMessage(translated, true);
            }
            else
            {
                player.ParseMessage(translated, false);
            }
        } else {
            player.Message("Usage: /translate [lang] [message]");
        }
    }
    catch
    {
        player.Message("Usage: /translate [lang] [message]");
    }
}

Answer 1

首先确保您获得下载内容的正确编码。请参阅此SO答案有关如何执行此操作的代码。

基本上检查 http 标头和元标记的编码，并在必要时重新编码内容。然后执行 HttpUtility.HtmlDecode 来删除任何 html 编码字符。现在您已准备好开始搜索您想要查找的任何内容。

我还建议使用 Html Agility Pack 之类的东西来解析 html 而不是 indexof。

Answer 2

很难说您的 ParseMessage 方法到底期望什么，因此这只是一个猜测：

您从 Google Translate 获得的结果是 HTML 格式的。这意味着如果您想要纯文本输出，则必须将 HTML 转换为文本。您已经成功（至少目前为止，直到 Google Translate 稍微更改其输出页面；您的解决方案并不完全可靠或面向未来）从 HTML 页面提取翻译。但翻译仍然采用 HTML 编码，您需要对其进行解码。为此，您可以使用 WebUtility.HtmlDecode 方法（假设您使用的是 .NET Framework 4）：在该

translated = html.Substring(a, b - a);

行后面添加

translated = WebUtility.HtmlDecode(translated);

Answer 3

在最后大量评论之前，与另一位开发人员的讨论让我尝试了这个。这是最终的工作结果：

    internal static void TranslateThis(Player player, string fromLang, string toLang, string text){
        try
        {
            string translated = null;
            text = Regex.Replace(text, @"[^\w\.\'\s@-]", "");
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://translate.google.com/?langpair=" + fromLang + "|" + toLang + "&text=" + text.Replace(" ", "+") + "#");

            request.MaximumAutomaticRedirections = 4;
            request.MaximumResponseHeadersLength = 4;

            request.Credentials = CredentialCache.DefaultCredentials;
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();

            Stream receiveStream = response.GetResponseStream();

            StreamReader readStream = new StreamReader(receiveStream, Encoding.UTF7);
            String html = readStream.ReadToEnd() + "";
            int a = html.IndexOf("onmouseout=\"this.style.backgroundColor='#fff'\">") + 47;
            int b = html.IndexOf("</span>",html.IndexOf("onmouseout=\"this.style.backgroundColor='#fff'\">") + 47);
            translated = html.Substring(a, b - a);
            response.Close();
            readStream.Close();
            if (translated.Length < (10 * text.Length))
            {
                translated = translated.Replace("'", "'");
                translated = Regex.Replace(translated, @"[^\w\.\'\s@-]", "");
                if (player == Player.Console)
                {
                    player.ParseMessage(translated, true);
                }
                else
                {
                    player.ParseMessage(translated, false);
                }
            }
            else
            {
                player.Message("Usage: /translate [lang] [message]");
            }
        }
        catch(Exception ex)
        {
            player.Message("Error:" + ex.ToString());

        }
   }