Question

嘿:)我真的很努力让WebClient回复我UTF-8。但是当sub应该返回类似Ä之类的东西时，我认为它更像E左右。

尝试了很多变通方法，但它不会起作用。

private string translate(string input, string languagePair)
{
    string url = String.Format("https://translate.google.com/?hl=en&ie=UTF8&text={0}&langpair={1}", input, languagePair);
    WebClient wc = new WebClient();
    wc.Headers.Add(HttpRequestHeader.AcceptCharset, "UTF-8");
    wc.Encoding = Encoding.UTF8;
    var data = wc.DownloadData(url);
    var result = Encoding.UTF8.GetString(data);
    //string result = wc.DownloadString(url);
    int start = result.IndexOf("result_box");
    string sub = result.Substring(start);
    sub = sub.Substring(0, sub.IndexOf("</span>"));
    start = sub.LastIndexOf(">");
    sub = sub.Substring(start + 1);
    return sub;
}

Answer 1

谷歌只是忽略AcceptCharset标题中发送的编码并返回ISO-8859-1中的回复，正如您从缩短的回复中看到的那样：

HTTP/1.1 200 OK
Content-Type: text/html; charset=ISO-8859-1
Content-Language: en
Content-Length: 64202

<!DOCTYPE html><html><head><meta content="text/html; charset=ISO-8859-1" http-equiv="content-type">

因此，当您使用UTF-8编码解码响应时，您将获得无效字符。如果您想让它快速运行，我发现当User-Agent标头添加到请求时，Google会以UTF-8返回响应，您可以不修改其余代码：

private static string translate(string input, string languagePair)
{
    string url = String.Format("https://translate.google.com/?hl=en&ie=UTF8&text={0}&langpair={1}", input, languagePair);
    WebClient wc = new WebClient();
    wc.Headers.Add(HttpRequestHeader.AcceptCharset, "utf-8");
    wc.Headers.Add(HttpRequestHeader.UserAgent, "Mozilla/5.0 (Windows NT 10.0; …) Gecko/20100101 Firefox/55.0");
    wc.Encoding = Encoding.UTF8;
    string result = wc.DownloadString(url);
    int start = result.IndexOf("result_box");
    string sub = result.Substring(start);
    sub = sub.Substring(0, sub.IndexOf("</span>"));
    start = sub.LastIndexOf(">");
    sub = sub.Substring(start + 1);
    return sub;
}

更好的解决方案是检测响应中使用的编码并将其用于解码。 WebClient内置了此检测功能，因此您可以使用here描述的解决方案或使用HttpClient代替，这会自动为您执行此操作：

private static async Task<string> translate(string input, string languagePair)
{
    string url = String.Format("https://translate.google.com/?hl=en&ie=UTF8&text={0}&langpair={1}", input, languagePair);
    using (var hc = new HttpClient())
    {
        var result = await hc.GetStringAsync(url).ConfigureAwait(false);
        int start = result.IndexOf("result_box");
        string sub = result.Substring(start);
        sub = sub.Substring(0, sub.IndexOf("</span>"));
        start = sub.LastIndexOf(">");
        sub = sub.Substring(start + 1);
        return sub;
    }
}

另请注意，Google有Translation API，这可能更适合使用而不是解析HTML页面的翻译。

C＃WebClient不会返回UTF-8

1 个答案: