Google Translate API Usage in C#

Introduction

We would like to easily translate a string of text to another language. The results returned from the Google Translate API are very cryptic. They are in the form of a JSON jagged array. It is even harder when you have to translate multiple sentences. This tip describes how to properly use the free API using C#.

Requirements

You must add a reference to System.Web.Extensions. Then add the following using directives:

using System.Net.Http;
using System.Collections;
using System.Web.Script.Serialization;

Example Translate Function

Add the following function to your code:

public string TranslateText(string input)
    {
      // Set the language from/to in the url (or pass it into this function)
      string url = String.Format
      ("https://translate.googleapis.com/translate_a/single?client=gtx&sl={0}&tl={1}&dt=t&q={2}",
       "en", "es", Uri.EscapeUriString(input));
      HttpClient httpClient = new HttpClient();
      string result = httpClient.GetStringAsync(url).Result;

      // Get all json data
      var jsonData = new JavaScriptSerializer().Deserialize<List<dynamic>>(result);

      // Extract just the first array element (This is the only data we are interested in)
      var translationItems = jsonData[0];

      // Translation Data
      string translation = "";

      // Loop through the collection extracting the translated objects
      foreach (object item in translationItems)
      {
        // Convert the item array to IEnumerable
        IEnumerable translationLineObject = item as IEnumerable;

        // Convert the IEnumerable translationLineObject to a IEnumerator
        IEnumerator translationLineString = translationLineObject.GetEnumerator();

        // Get first object in IEnumerator
        translationLineString.MoveNext();

        // Save its value (translated text)
        translation += string.Format(" {0}", Convert.ToString(translationLineString.Current));
      }

      // Remove first blank character
      if (translation.Length > 1) { translation = translation.Substring(1); };

      // Return translation
      return translation;
    }

Set the from/to language in the following line. In this case, en (from language) and es (to language):

string url = String.Format
("https://translate.googleapis.com/translate_a/single?client=gtx&sl={0}&tl={1}&dt=t&q={2}", 
"en", "es", Uri.EscapeUriString(input));

Then call your code:

string translatedText = TranslateText(text);

Points of Interest

You will only be allowed to translate about 100 words per hour using the free API. If you abuse this, Google API will return a 429 (Too many requests) error.

History

• 10/4/2019: Original version