原資料為網上找到的原稿為:http://www.cnblogs.com/marso/p/google_translate_api.html(此處只做個人筆記參考)

主要分兩塊：通過WebRequest的方式請求內容；獲取Get方式的請求參數（難點在於tk的獲取）。

以下是TK的JS代碼,把以下代碼保存存到程序目錄下

gettk.js

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)
} 

然後在C#程序只引入Json.net(這個我用的版本為net4.5),然後再引入system.wed.dll(文件目錄為:C:\WINDOWS\Microsoft.NET\Framework\找到相應版本)

以下為測試程序

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Web;


namespace ConsoleApplication1
{
    class Program
    {
        

           static void Main(string[] args)
        {
                       google test = new google();
            Console.WriteLine(test.GoogleTranslate("RCC_APB2Periph: specifies the APB2 peripheral to gates its clock.This parameter can be any combination of the following values", "auto", "zh-CN"));
            Console.ReadKey();
        }
       
        
    }
    class google
    {
        /// 
        /// 谷歌翻譯
        /// 
        /// 待翻譯文本
        /// 自動檢測：auto
        /// 中文：zh-CN，英文：en
        /// 翻譯後文本
        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中正則匹配TKK的JS代碼

            var TKK = ExecuteScript(TKKStr, TKKStr);//執行TKK代碼，得到TKK值

            var GetTkkJS = File.ReadAllText("./gettk.js");

            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, "https://translate.google.cn/");

            dynamic TempResult = Newtonsoft .Json.JsonConvert.DeserializeObject(ResultHtml);

            string ResultText = Convert.ToString(TempResult[0][0][0]);

            return ResultText;
        }

        public string GetResultHtml(string url, CookieContainer cookie, string refer)
        {
            var html = "";

            var webRequest = WebRequest.Create(url) as HttpWebRequest;

            webRequest.Method = "GET";

            webRequest.CookieContainer = cookie;

            webRequest.Referer = refer;

            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.UserAgent = " Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0)";

            using (var webResponse = (HttpWebResponse)webRequest.GetResponse())
            {
                using (var reader = new StreamReader(webResponse.GetResponseStream(), Encoding.UTF8))
                {

                    html = reader.ReadToEnd();
                    reader.Close();
                    webResponse.Close();
                }
            }
            return html;
        }

        /// 

        /// 執行JS
        /// 

        /// 參數體
        /// JavaScript代碼的字符串
        /// 
        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;
        }
    }
}

C#調用谷歌翻譯API