unity免费使用谷歌翻译(使用tk值，防止数量限制的错误)

如果直接使用

string url = "https://translate.googleapis.com/translate_a/single?client=gtx&sl="                     + sourceLang + "&tl=" + targetLang + "&dt=t&q=" + UnityWebRequest.EscapeURL(sourceText);

这种url去谷歌翻译那里获取翻译的话，会有限制，因为没有token值，所以很容易会给谷歌那边屏蔽ip，无法再翻译。后面找了一下资料，发现有些是使用了tk值的方式来访问谷歌翻译，经过验证，很频繁(每隔0.2s翻译一条)翻译，翻译是上万条也没出现给限制的情况。这种方法的难点就在tk值的获取，其实tk值在使用GET方式访问https://translate.google.cn的时候就可以获取到，但是这个tk值还需要做一些处理，才能重新使用。下面说下怎么获取。

using UnityEngine; using System.Collections; using UnityEngine.Networking; using YIMEngine; using System; using System.Text.RegularExpressions; using System.Collections.Generic;

public class Translate {     protected struct ExternalKey     {         /// <summary>         /// Total hours         /// </summary>         public long Time { get; }

        /// <summary>         /// Token value         /// </summary>         public long Value { get; }

        /// <param name="time">Unix-formatted total hours</param>         /// <param name="value">Token value</param>         public ExternalKey(long time, long value)         {             Time = time;             Value = value;         }     }

    protected static int UnixTotalHours     {         get         {             DateTime unixTime = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);             return (int)DateTime.UtcNow.Subtract(unixTime).TotalHours;         }     }     // We have use googles own api built into google Translator.     public static IEnumerator Process(string targetLang, string sourceText, System.Action<string, int> result, int times)     {         yield return Process("auto", targetLang, sourceText, result, times);     }

    // Exactly the same as above but allow the user to change from Auto, for when google get's all Jerk Butt-y     public static IEnumerator Process(string sourceLang, string targetLang, string sourceText, System.Action<string, int> result,         int times)     {         //第一步，先使用GET方式访问谷歌翻译，拿到html的tk值         string urlte = "https://translate.google.cn";         UnityWebRequest request1 = new UnityWebRequest(urlte, "GET");

        request1 .SetRequestHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36");         request1 .downloadHandler = (DownloadHandler)new DownloadHandlerBuffer();         request1 .useHttpContinue = false;//应对某些机型的errorCallback with error=java.io.EOFException         yield return request1.SendWebRequest();         if (request1.isNetworkError || request1.isHttpError)         {             Debug.LogError("获取服务器列表失败 = " + request1.error);             result.Invoke("", times);             yield break;         }

        long tkk = 0;

        try         {             //这个就是返回的初始tk值             var tkkText = request1.downloadHandler.text.GetTextBetween(@"tkk:'", "',");

            if (tkkText == null)             {                 result.Invoke("", times);             }

            var splitted = tkkText.Split('.');             if (splitted.Length != 2 || !long.TryParse(splitted[1], out tkk))             {                 result.Invoke("", times);             }

        }         catch (ArgumentException)         {             result.Invoke("", times);         }

        var currentExternalKey = new ExternalKey(UnixTotalHours, tkk);         long time = DecrypthAlgorythm(sourceText, currentExternalKey);

        string tk = time.ToString() + '.' + (time ^ currentExternalKey.Time);

        string address = "https://translate.google.cn/translate_a/single";         string url =$"{ address}" + "?" +                      $"sl={sourceLang}&" +                     $"tl={targetLang}&" +                     $"hl={sourceLang}&" +                     $"q={UnityWebRequest.EscapeURL(sourceText)}&" +                     $"tk={tk}&" +                     "client=t&" +                     "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=7";         //Debug.Log("地址=" + url);         //string url = string.Format("https://translate.google.cn/translate_a/single?client=t&sl={0}&tl={1}&hl={0}&dt=bd&dt=ex&dt=ld&dt=md&dt=qca&dt=rw&dt=rm&dt=ss&dt=t&dt=at&ie=UTF-8&oe=UTF-8&ssel=6&tsel=3&kc=0&tk=" + tk + "&q={2}", sourceLang, targetLang, UnityWebRequest.EscapeURL(sourceText));         /*        string url = "https://translate.googleapis.com/translate_a/single?client=gtx&sl="                     + sourceLang + "&tl=" + targetLang + "&dt=t&q=" + UnityWebRequest.EscapeURL(sourceText);*/         UnityWebRequest request = new UnityWebRequest(url, "GET");         //request.SetRequestHeader("Content-Type", "application/json;charset=utf-8");         request.SetRequestHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36");         request.downloadHandler = (DownloadHandler)new DownloadHandlerBuffer();         request.useHttpContinue = false;//应对某些机型的errorCallback with error=java.io.EOFException         yield return request.SendWebRequest();         if (request.isNetworkError || request.isHttpError)         {             Debug.LogError("获取服务器列表失败 = " + request.error);             result.Invoke("", times);             yield break;         }                  JsonData jsonData = JsonMapper.ToObject(request.downloadHandler.text);         string translatedText = jsonData[0][0][0].ToString();         //Debug.Log("返回的text=" + request.downloadHandler.text);         Debug.Log("解析后=" + translatedText);         result.Invoke(translatedText, times);     }

    private static long DecrypthAlgorythm(string source, ExternalKey CurrentExternalKey)     {         List<long> code = new List<long>();

        for (int g = 0; g < source.Length; g++)         {             int l = source[g];             if (l < 128)             {                 code.Add(l);             }             else             {                 if (l < 2048)                 {                     code.Add(l >> 6 | 192);                 }                 else                 {                     if (55296 == (l & 64512) && g + 1 < source.Length && 56320 == (source[g + 1] & 64512))                     {                         l = 65536 + ((l & 1023) << 10) + (source[++g] & 1023);                         code.Add(l >> 18 | 240);                         code.Add(l >> 12 & 63 | 128);                     }                     else                     {                         code.Add(l >> 12 | 224);                     }                     code.Add(l >> 6 & 63 | 128);                 }                 code.Add(l & 63 | 128);             }         }

        long time = CurrentExternalKey.Time;

        foreach (long i in code)         {             time += i;             Xr(ref time, "+-a^+6");         }

        Xr(ref time, "+-3^+b+-f");

        time ^= CurrentExternalKey.Value;

        if (time < 0)             time = (time & int.MaxValue) + 2147483648;

        time %= (long)1e6;

        return time;     }

    private static void Xr(ref long a, string b)     {         for (int c = 0; c < b.Length - 2; c += 3)         {             long d = b[c + 2];

            d = 'a' <= d ? d - 87 : (long)char.GetNumericValue((char)d);             d = '+' == b[c + 1] ? (long)((ulong)a >> (int)d) : a << (int)d;             a = '+' == b[c] ? a + d & 4294967295 : a ^ d;         }     } }

下面是string的拓展方法

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Xml;

static class StringExtension {     internal static string GetTextBetween(this string src, string from, string to, int startIndex = 0)     {         if (src == null)             throw new ArgumentNullException(nameof(src));         if (from == null)             throw new ArgumentNullException(nameof(from));         if (to == null)             throw new ArgumentNullException(nameof(to));         if (startIndex < 0 || startIndex > src.Length - 1)             throw new ArgumentOutOfRangeException(nameof(to));

        int index = src.IndexOf(from, startIndex, StringComparison.Ordinal);         if (index == -1)             return null;

        int index2 = src.IndexOf(to, index, StringComparison.Ordinal);         if (index2 == -1)             return null;

        var result = src.Substring(index + from.Length, index2 - index - from.Length);         return result;     }

    internal static string ToCamelCase(this string src)     {         string[] words = src.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);

        return string.Concat(words.Select(word             => char.ToUpper(word[0]) + word.Substring(1).ToLower()));     }

}