谷歌会忽略在 AcceptCharset
头部发送的编码,并以 ISO-8859-1
返回响应,如您从缩短的响应中所见:
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,会出现无效字符。如果您只想快速使其工作,我发现当在请求中添加
User-Agent
头时,Google会以UTF-8返回响应,您可以保持其余代码不变:
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;
}
更好的解决办法是检测响应中使用的编码并将其用于解码。
WebClient
没有内置此检测功能,因此您可以使用
此处描述的解决方案,或者改为使用
HttpClient
,后者会自动执行此操作:
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;
}
}
另外请注意,谷歌有
翻译API,可能比从HTML页面解析翻译更好。
input
和languagePair
) - Richard Schneider