C# Web api post parameter always null

Question

I'm doing a web API in c# with token, but I need to receive the parameters of postman to my method

 [HttpPost, Route("api/cobro/saveEmail")]
    public IHttpActionResult SaveEmailForDiscount([FromBody] string email)
    {
        //do something with e-mail
        return Ok(email);
    }

But always the email is null

This is the PostMan request

POST /api/cobro/saveEmail HTTP/1.1
Host: localhost:53107
Content-Type: application/x-www-form-urlencoded
Cache-Control: no-cache
Postman-Token: 881045b2-0f08-56ac-d345-ffe2f8f87f5e

email=jose%40gm.com

This is my Startup class where is all config

    using System;
using Microsoft.Owin;
using Owin;
using Microsoft.Owin.Security.OAuth;
using System.Web.Http;
using System.Net.Http.Headers;

[assembly: OwinStartup(typeof(Cobros_BackEnd.Startup))]

namespace Cobros_BackEnd
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {


     app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);

        var MyProvider = new AuthorizationServerProvider();
        OAuthAuthorizationServerOptions options = new OAuthAuthorizationServerOptions
        {

            AllowInsecureHttp = true,
            TokenEndpointPath = new PathString("/token"),
            AccessTokenExpireTimeSpan = TimeSpan.FromDays(1),
            Provider = MyProvider
        };
        app.UseOAuthAuthorizationServer(options);
        app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());

        HttpConfiguration config = new HttpConfiguration();
        config.Formatters.JsonFormatter.SupportedMediaTypes
        .Add(new MediaTypeHeaderValue("text/xml"));

        //get all users
        config.Routes.MapHttpRoute(
            name: "Users",
            routeTemplate: "api/{controller}/users",
            defaults: new { id = RouteParameter.Optional }
            );



        WebApiConfig.Register(config);
    }
  }
}

I'm using other methods in GET and all work fine, but I need to use this on POST

score 2 · Answer 1 · answered Mar 17 '17 at 20:27

try this in the body of your request: =jose%40gm.com

Web Api does not play nice with simple types being passed in the body of a post. You need to actually implement a custom data binder to be able to do this. What I just put is a work around. I avoid posting simple types in body at all costs in Web api. Id prefer to make a Model object and then send the data in JSON which will map to my model. You can also use [FromUri] and pass your string inside the url.

Can you give an example or a reference? – joe06 Mar 17 '17 at 20:36 — joe06, Mar 17 '17 at 20:36

score 2 · Accepted Answer · answered Mar 17 '17 at 20:55

2

you can create a class wrapper email field like this

public class SaveEmailModel{
    public string Email{get;set;}
}

public IHttpActionResult SaveEmailForDiscount([FromBody] SaveEmailModel model){
...
}

answered Mar 17 '17 at 20:55

danfox

54
2

This is the easiest solution to this problem IMO – victor Mar 20 '17 at 14:18

C# Web api post parameter always null

2 Answers2