使用谷歌翻译C#版本.

string GetTkkJS = @"
var b = function (a, b) 
{
for (var d = 0; d < b.length - 2; d += 3) 
{
var c = b.charAt(d + 2),
c = ""a"" <= c ? c.charCodeAt(0) - 87 : Number(c),
c = ""+"" == b.charAt(d + 1) ? a >>> c : a << c;
a = ""+"" == b.charAt(d) ? a + c & 4294967295 : a ^ c
}
return a
}


var tk = function (a,TKK) {
for (var e = TKK.split("".""), h = Number(e[0]) || 0, g = [], d = 0, f = 0; f < a.length; f++) 
{
var c = a.charCodeAt(f);
128 > c ? g[d++] = c : (2048 > c ? g[d++] = c >> 6 | 192 : (55296 == (c & 64512) && f + 1 < a.length 
&& 56320 == (a.charCodeAt(f + 1) & 64512) ? (c = 65536 + ((c & 1023) << 10) + (a.charCodeAt(++f) & 1023), g[d++] = c >> 18 | 240,
g[d++] = c >> 12 & 63 | 128) : g[d++] = c >> 12 | 224, g[d++] = c >> 6 & 63 | 128), g[d++] = c & 63 | 128)
}
a = h;
for (d = 0; d < g.length; d++) a += g[d], a = b(a, ""+-a^+6"");
a = b(a, ""+-3^+b+-f"");
a ^= Number(e[1]) || 0;
0 > a && (a = (a & 2147483647) + 2147483648);
a %= 1E6;
return a.toString() + ""."" + (a ^ h)
}";

       
        /// <summary>  
        /// 谷歌翻译  
        /// </summary>  
        /// <param name="text">待翻译文本</param>  
        /// <param name="fromLanguage">自动检测：auto</param>  
        /// <param name="toLanguage">中文：zh-CN，英文：en</param>  
        /// <returns>翻译后文本</returns>  
        public string GoogleTranslate(string text, string fromLanguage, string toLanguage)
        {
            CookieContainer cc = new CookieContainer(); 
            string GoogleTransBaseUrl = "https://translate.google.cn/"; 
            var BaseResultHtml = GetResultHtml(GoogleTransBaseUrl, cc, ""); 
            Regex re = new Regex(@"(?<=TKK=)(.*?)(?=\);)"); 
             
            var TKKStr = re.Match(BaseResultHtml).ToString() + ")";//在返回的HTML中正则匹配TKK的JS代码   
            
            var TKK = ExecuteScript(TKKStr, TKKStr);//执行TKK代码，得到TKK值     
            var tk = ExecuteScript("tk(\"" + text + "\",\"" + TKK + "\")", GetTkkJS);
            
            string googleTransUrl = "https://translate.google.cn/translate_a/single?client=t&sl=" + fromLanguage 
                + "&tl=" + toLanguage + "&hl=en&dt=at&dt=bd&dt=ex&dt=ld&dt=md&dt=qca&dt=rw&dt=rm&dt=ss&dt=t&ie=UTF-8&oe=UTF-8&otf=1&ssel=0&tsel=0&kc=1&tk=" 
                + tk + "&q=" + HttpUtility.UrlEncode(text);
 
            var ResultHtml = GetResultHtml(googleTransUrl, cc, "");
           
            dynamic TempResult = Newtonsoft.Json.JsonConvert.DeserializeObject(ResultHtml); //转换为json
            
           //结果示例
           //ResultText = ‘[[["I love you","我爱你",null,null,1],[null,null,null,"Wǒ ài nǐ"]],null,"zh-CN",null,null,[["我爱你",null,[["I love you",1000,true,false]],
           //                   [[0,3]],"我爱你",0,0]],1,null,[["zh-CN"],null,[1],["zh-CN"]],null,null,null,null,null,[["我","爱","你"]]]‘
            string ResultText = Convert.ToString(TempResult[0][0][0]);                      //数组json,第一个数组里边的第一个数组的第一个内容.嵌套数据,
            return ResultText;
        }  
 
        public string GetResultHtml(string url, CookieContainer cookie, string referer)
        {
            var html = ""; 
            var webRequest = WebRequest.Create(url) as HttpWebRequest; 
            webRequest.Method = "GET"; 
            /*网上程序代码,自己用chrome浏览器F12查看追踪修改为下列两行,同样执行成功.20180427
            //webRequest.CookieContainer = cookie; 
            //webRequest.Referer = referer; 
            //webRequest.Timeout = 20000; 
            //webRequest.Headers.Add("X-Requested-With:XMLHttpRequest"); 
            //webRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8";

            webRequest.Accept = "*/*";  
            webRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36";

            using (var webResponse = (HttpWebResponse)webRequest.GetResponse())
            {
                using (var reader = new StreamReader(webResponse.GetResponseStream(), Encoding.UTF8))
                { 
                    html = reader.ReadToEnd();
                    reader.Close();
                    webResponse.Close();
                }
            }
            return html;
        }  
     
         
        /// <summary>
        /// 执行JS
        /// </summary>
        /// <param name="sExpression">参数体</param>
        /// <param name="sCode">JavaScript代码的字符串</param>
        /// <returns></returns>
        private string ExecuteScript(string sExpression, string sCode)
        {
            
            MSScriptControl.ScriptControl scriptControl = new MSScriptControl.ScriptControl();
            scriptControl.UseSafeSubset = true;
            scriptControl.Language = "JScript";
            scriptControl.AddCode(sCode);
            try
            {
                string str = scriptControl.Eval(sExpression).ToString();
                return str;
            }
            catch (Exception ex)
            {
                string str = ex.Message;
            }
            return null;
        }