How to send remote mp3 file to Telegram channel using Telegram Bot API's sendAudio method in C#

Question

I create a bot (@mp3lyric_bot_test) in telegram and set it as administrator in my channel (@mp3lyric_test). Now I want to make a request to send an mp3 to channel using telegram api.

my mp3 is in web, something like this: http://bayanbox.ir/download/7028444634071302239/Sound-1.mp3

At first i download mp3 with this method:

    public static Task<byte[]> DownloadAsync(string requestUriSt)
    {
        var requestUri = new Uri(requestUriSt);

        byte[] fileBytes;

        using (var httpClient = new HttpClient())
        {
            using (var request = new HttpRequestMessage(HttpMethod.Get, requestUri))
            {
                using (var responseMessage = await httpClient.SendAsync(request))
                {
                    fileBytes = await responseMessage.Content.ReadAsByteArrayAsync();
                    var audioString = Encoding.UTF8.GetString(fileBytes, 0, fileBytes.Length);
                }
            }
        }

        return fileBytes;
    }

• if there is a way to send mp3 directly without download, please tell me how? thanks.

Then send that byte array (fileBytes) using this code:

• my bot token is 247655935:AAEhpYCeoXA5y7V8Z3WrVcNJ3AaChORjfvw

      using (var client = new HttpClient())
      {
          var uri = new Uri("https://api.telegram.org/bot247655935:AAEhpYCeoXA5y7V8Z3WrVcNJ3AaChORjfvw/sendAudio");
  
          using (var multipartFormDataContent = new MultipartFormDataContent(
              "SendAudio----" + DateTime.Now.ToString(CultureInfo.InvariantCulture)))
          {
              multipartFormDataContent.Add(
                  new StringContent("@mp3lyric_test"), 
                  string.Format("\"{0}\"", "chat_id")
              );
  
              multipartFormDataContent.Add(
                  new StreamContent(new MemoryStream(fileBytes)), 
                  '"' + "audio" + '"'
              );
  
              using (var message = await client.PostAsync(uri, multipartFormDataContent))
              {
                  var contentString = await message.Content.ReadAsStringAsync();
              }
          }
      }
  

I have two error:

1. "Request Entity Too Large" when my mp3 is about 6mb or 7mb or ... (not using http://bayanbox.ir/download/7028444634071302239/Sound-1.mp3)

2. error_code:400, description:"Bad Request: URL must be in UTF-8" (after using that mp3 for test that is 28kb)

Answer 1

I chaged my codes for send the byte array (fileBytes) and now it works:

using (var client = new HttpClient())
{
    var uri = new Uri("https://api.telegram.org/bot247655935:AAEhpYCeoXA5y7V8Z3WrVcNJ3AaChORjfvw/sendAudio?chat_id=@mp3lyric_test");

    using (var multipartFormDataContent = new MultipartFormDataContent())
    {
        var streamContent = new StreamContent(new MemoryStream(fileBytes));
        streamContent.Headers.Add("Content-Type", "application/octet-stream");
        streamContent.Headers.Add("Content-Disposition", "form-data; name=\"audio\"; filename=\"Sound-1.mp3\"");
        multipartFormDataContent.Add(streamContent, "file", "Sound-1.mp3");

        using (var message = await client.PostAsync(uri, multipartFormDataContent))
        {
            var contentString = await message.Content.ReadAsStringAsync();
        }
    }
}