Retrieve Json Data as a IEnumerable RSS

• • Reply
  sakuradata

  Member

  1 Points

  67 Posts

  Retrieve Json Data as a IEnumerable

  Oct 06, 2020 09:57 AM|sakuradata|LINK

  Goal:
  Send a json data with many data from frontend to backend.

  Problem:
  When I send the data to the backend i do not retrieve it as a IEnumerable

  What part of the code am I missing?

  Info:
  *Using JQuery as a frontend
  *Using Asp.net mvc as a backend

  Thank you!

  @{
      ViewData["Title"] = "Home Page";
  }
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
  
  
  <button class="testtest">
      dfdf
  </button>
  
  <script type="text/javascript">
  
      $('.testtest').click(function () {
  
          var txt = '{"name":"John", "age":30, "city":"New York"}'
          var obj = JSON.parse(txt);
  
          $.ajax({
              url: '@Url.Action("TestGet")',
              data:
              {
                  contactcollection: obj
              },
              dataType: 'json',
              type: 'Get',
              contentType: 'application/json',
              success: function (result) {
  
                  var display = '';
  
  
                  return;
              }
          });
  
      });
  
  </script>

  using System;
  using System.Collections.Generic;
  using System.Diagnostics;
  using System.Linq;
  using System.Threading.Tasks;
  using Microsoft.AspNetCore.Mvc;
  using JsonData.Models;
  
  namespace JsonData.Controllers
  {
      public class HomeController : Controller
      {
          public IActionResult Index()
          {
              return View();
          }
  
  
          [HttpGet]
          public JsonResult TestGet(IEnumerable<Contact> contactcollection)
          {
  
              int ddd = 23;
  
              return Json(null);
          }
      }
  
      public class Contact
      {
          public string name;
          public int age;
          public string city;
      }
  }

• • Reply
  mgebhard

  All-Star

  53041 Points

  23612 Posts

  Re: Retrieve Json Data as a IEnumerable

  Oct 06, 2020 12:48 PM|mgebhard|LINK

  sakuradata

  Problem:
  When I send the data to the backend i do not retrieve it as a IEnumerable

  What part of the code am I missing?

  There are several issues with the code; the model contains fields but should have properties, the JSON is not a collection, AJAX should POST JSON, and typically you have a JSON object that is serialized to a string. 

  // GET: Ajax
  [HttpGet]
  public ActionResult Index()
  {
      return View();
  }
  
  [HttpPost]
  public ActionResult Index(IEnumerable<Contact> contactcollection)
  {
      return Json(contactcollection);
  }

  <script>
      $('.testtest').click(function () {
  
          var data = [
              {
                  name: "John",
                  age: 30,
                  city: "New York"
              }   
          ];
                  
          var json = JSON.stringify(data);
          console.log(json);
  
          $.ajax({
              type: 'post',
              url: '@Url.Action("Index")',
              contentType: 'application/json',
              dataType: 'json',                    
              data: json,            
              success: function (result) {
                  console.log(result);               
              }
          });
  
      });
  </script>

• • Reply
  bruce (sqlwo...

  All-Star

  58194 Points

  15655 Posts

  Re: Retrieve Json Data as a IEnumerable

  Oct 06, 2020 02:27 PM|bruce (sqlwork.com)|LINK

  In addition, IEnumerable is an interface, not a concrete class so the binder can not create an instance of it to bind to.

  bruce (sqlwork.com)
• • Reply
  Jerry Cai

  Participant

  980 Points

  319 Posts

  Re: Retrieve Json Data as a IEnumerable

  Oct 07, 2020 08:59 AM|Jerry Cai|LINK

  Hi,sakuradata

  sakuradata

  When I send the data to the backend i do not retrieve it as a IEnumerable

  First,you should use [HttpPost] to get the parameters from view. Then if you want to get a list,  the data passed to the controller should be a list too, you can refer to my demo:

  View:

  <button class="testtest">
      dfdf
  </button>
  
  @section Scripts
  {
      <script>
           $('.testtest').click(function () {
               var txt = '{"name":"John", "age":30, "city":"New York"}';
                      var obj = JSON.parse(txt);
                      var list = new Array();
                      list.push(obj);
  
               $.ajax({
                  type: 'POST',
                  url: "/Home/TestGet",
                  data: { "contactcollection": list},
                  success: function (result) {
                  }
              });
      });
      </script>
  }

  Controller:

  [HttpPost]
          public IActionResult TestGet(IEnumerable<Contact> contactcollection)
          {
              return Json(null);
          }

  Result:

  

  Best Regards,

  Jerry Cai

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