Asp.net MVC calling Login web service

Question

I am new to Asp.Net, What i want to do is . I have a Web API for Login service , that returns a json Data. Sample url of Web APi

http://localhost:55500/api/Login/submit?username=abc&password=abc123

It returns a json data like

[{"UserID":0,
  "Status":"True",
  "Name":"885032-59-6715",
  "DepName":"Ajay"} 
]

How can i authenticate my login page in Asp.NET MVC. If login success (Status:True). I should redirect to dashboard and display the json data in my view page. If login not successfull, it should show the error message

My ASP.NET MVC model calss File :

namespace LoginPracticeApplication.Models{
  public class Login {

    [Required(ErrorMessage = "Username is required")] // make the field required
    [Display(Name = "username")]  // Set the display name of the field
    public string username { get; set; }

    [Required(ErrorMessage = "Password is required")]
    [Display(Name = "password")]
    public string password { get; set; }       
  }}

My ASP.NET MVC Controller File :

public ActionResult Index(Login login)
{
  if (ModelState.IsValid) // Check the model state for any validation errors
  {
      string uname = "";
      uname = login.username;
      string pword = "";
      pword = login.password;

      string url = "http://localhost:55506/api/Login/submit?username=" + uname + "&password=" + login.password + "";
      System.Net.Http.HttpClient client = new System.Net.Http.HttpClient();
      client.BaseAddress = new Uri(url);
      client.DefaultRequestHeaders.Accept.Clear();
      client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
      HttpResponseMessage responseMessage = client.GetAsync(url).Result;

      var responseData = responseMessage.Content.ReadAsStringAsync().Result;
      if (responseData=="true")
      {                    
          return View("Show", login); // Return the "Show.cshtml" view if user is valid
      }
      else
      {
          ViewBag.Message = "Invalid Username or Password";
          return View(); //return the same view with message "Invalid Username or Password"
      }
  }
  else
  {
      return View();
  }
  return View();
}

When i tried to login with this above code. It always shows "Invalid Username or Password". So thanks in advance for your help. Looking forward for success

Answer 1

I believe that the problem is at:

          var responseData = responseMessage.Content.ReadAsStringAsync().Result;
          if (responseData=="true")
          {                    
              return View("Show", login); // Return the "Show.cshtml" view if user is valid
          }
          else
          {
              ViewBag.Message = "Invalid Username or Password";
              return View(); //return the same view with message "Invalid Username or Password"
          }

As you are ReadAsStringAsync() the response, probably is returning the JSON that you mentioned [{"UserID":0,"Status":"True","Name":"885032-59-6715","DepName":"Ajay"}] what means that the test responseData=="true" aka. "[{"UserID":0,"Status":"True","Name":"885032-59-6715","DepName":"Ajay"}]" == "true" will result in being false.

You could use responseData.Contains("true") but I don´t believe this is the best approach.

I think that the way to go is, after you ReadAsStringAsync() you should deserialize the string (json) into an object through JsonConvert.DeserializeObject<LoginResultModel>(responseData); . The JsonConvert is in Newtonsoft.Json that you can get by Nuget. In the LoginResultModel you should create considering your json. I believe it would be something like:

public class LoginResultModel
{
    public int UserID { get; set; }

    public bool Status { get; set; }

    public string Name { get; set; }

    public string DepName { get; set; }
}

And as you are returning an array you should deserialize to a list of LoginResultModel: JsonConvert.DeserializeObject<List<LoginResultModel>>(responseData);

PS.: You could have debug to see the data that responseData was getting and understand why it was evaluating to false.

Regards