Twilio - 获取来电号码 C#

Question

In my C# asp.net core web api project I am using webhooks to capture the incoming voice call from my Twilio phone number. In addition to handling the call, I would like to notify the admin for the incoming call via email. To do this I need to get the incoming phone number. How do I do that?

Here is my code:

[HttpPost("incomingVoice")]
public async Task<IActionResult> IncomingVoice(string digits)
{
    var response = new VoiceResponse();

    if (!string.IsNullOrEmpty(digits))
    {
        ... Handle the user selection
    }

    response.Append(new Gather(numDigits: 1).Say("Welcome to ...! For sales, press 1. For marketing, press 2. For support press 3", voice: "alice", language: "en-GB"));

    //handle the lack of response
    response.Say("Please leave a message after the tone.  Hang up when finished.", voice: "alice", language: "en-GB");
    response.Record();
    response.Hangup();

    string phoneNumber = <??? INCOMING PHONE NUMBER ???>

    IRestResponse mgresp = await SendMGMessage(phoneNumber);

    return Content(response.ToString(), "application/xml");
}

Thank you.

Answer 1

After some digging around, I found this link: https://www.twilio.com/docs/api/twiml/twilio_request

In it, it is specified that the TwiML request includes a whole variety of parameters. From there I was able to extract the phone number as:

string phoneNumber = Request.Form["From"];

Hope that saves you some research time.

Answer 2

In addition to dpdragnev's solution , you can print out all of the available values like this...

[HttpGet]
public TwiMLResult Welcome()
{
  var lst = Request.QueryString.AllKeys
    .Select(key => new {Name = key.ToString(), Value = Request.QueryString[key.ToString()]})
    .ToArray();
  foreach (var v in lst)
  {
    _logger.Info(JsonConvert.SerializeObject(v, Formatting.Indented));
  }
  ...
}

NLog sample output:

2019-05-07 17:00:36.7601|INFO|TwilioMvcDemo.Controllers.IvrController|{
  "Called": "+15555555555",
  "ToState": "CA",
  "CallerCountry": "US",
  "Direction": "inbound",
  "ApiVersion": "2010-04-01",
  "CallStatus": "ringing",
  "From": "+15555554444",
  "AccountSid": "CdEf567",
  "CalledCountry": "US",
  "CallerCity": "MARS OUTPOST",
  ...
}

Answer 3

I had a similar problem, but I am trying to solve this using Minimal Web API with .NET 6.

Twilio has this great tutorial:

https://www.twilio.com/blog/sms-voice-do.net-6-minimal-api

But it didn't answer how to access the incoming phone number from inside the webhook.

I'm not sure how to convert from Microsoft.AspNetCore.HttpRequest object to the preferred Twilio.AspNet.Common.SmsRequest object.

The below code appears to work, but would welcome advice for a better approach.

//app.MapPost("/smshandler", (SmsRequest incomingMessage) => SmsHandler(incomingMessage));  // does not work
app.MapPost("/smshandler", (HttpRequest request) => SmsHandler(request));

private static IResult SmsHandler(HttpRequest request)
    {
        try
        {
            string from = request.Form["From"];
            string body = request.Form["Body"];

            DoWork(from, body);
            return Results.Ok();
        }
        catch (Exception ex)
        {
            return Results.Problem(ex.Message);
        }
    }