System.NullReferenceException: 'Object reference not set to an instance of an object.' when trying to run new View.

Question

System.NullReferenceException: 'Object reference not set to an instance of an object.' when trying to run new View.

Mel 21

Can someone please have a look at my code and help me understand why I'm getting this error? I have set up a controller and model, but when trying to run this view I get this error.

Mel 21

View:

@model IEnumerable<BasicMVCProject.Models.Client>  
  
@{  
    ViewBag.Title = "Index";  
}  
  
<h2>Index</h2>  
  
<p>  
    @Html.ActionLink("Create New", "Create")  
</p>  
<table class="table">  
    <tr>  
        <th>  
            @Html.DisplayNameFor(model => model.FirstName)  
        </th>  
        <th>  
            @Html.DisplayNameFor(model => model.LastName)  
        </th>  
        <th>  
            @Html.DisplayNameFor(model => model.Phone)  
        </th>  
        <th>  
            @Html.DisplayNameFor(model => model.Email)  
        </th>  
        <th></th>  
    </tr>  
  
@foreach (var item in Model) {  
    <tr>  
        <td>  
            @Html.DisplayFor(modelItem => item.FirstName)  
        </td>  
        <td>  
            @Html.DisplayFor(modelItem => item.LastName)  
        </td>  
        <td>  
            @Html.DisplayFor(modelItem => item.Phone)  
        </td>  
        <td>  
            @Html.DisplayFor(modelItem => item.Email)  
        </td>  
        <td>  
            @Html.ActionLink("Edit", "Edit", new { /* id=item.PrimaryKey */ }) |  
            @Html.ActionLink("Details", "Details", new { /* id=item.PrimaryKey */ }) |  
            @Html.ActionLink("Delete", "Delete", new { /* id=item.PrimaryKey */ })  
        </td>  
    </tr>  
}  
  
</table>

The view is actually called Index.cshtml and is within the Client folder under view folders.

Mel 21

And model:

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Web;  
  
namespace BasicMVCProject.Models  
{  
    public class Client  
    {  
        public string FirstName { get; set; }  
        public string LastName { get; set; }  
        public int Phone { get; set; }  
        public string Email { get; set; }  
  
    }  
}

Answer accepted by question author

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Mel 21 Reputation points

2022-09-24T02:59:53.163+00:00

View:

@model IEnumerable<BasicMVCProject.Models.Client> @{ ViewBag.Title = "Index"; } <h2>Index</h2> <p> @Html.ActionLink("Create New", "Create") </p> <table class="table"> <tr> <th> @Html.DisplayNameFor(model => model.FirstName) </th> <th> @Html.DisplayNameFor(model => model.LastName) </th> <th> @Html.DisplayNameFor(model => model.Phone) </th> <th> @Html.DisplayNameFor(model => model.Email) </th> <th></th> </tr> @foreach (var item in Model) { <tr> <td> @Html.DisplayFor(modelItem => item.FirstName) </td> <td> @Html.DisplayFor(modelItem => item.LastName) </td> <td> @Html.DisplayFor(modelItem => item.Phone) </td> <td> @Html.DisplayFor(modelItem => item.Email) </td> <td> @Html.ActionLink("Edit", "Edit", new { /* id=item.PrimaryKey */ }) | @Html.ActionLink("Details", "Details", new { /* id=item.PrimaryKey */ }) | @Html.ActionLink("Delete", "Delete", new { /* id=item.PrimaryKey */ }) </td> </tr> } </table>

The view is actually called Index.cshtml and is within the Client folder under view folders.
Mel 21 Reputation points

2022-09-24T03:01:03.517+00:00

And model:

using System; using System.Collections.Generic; using System.Linq; using System.Web; namespace BasicMVCProject.Models { public class Client { public string FirstName { get; set; } public string LastName { get; set; } public int Phone { get; set; } public string Email { get; set; } } }

Answer 1

Lan Huang-MSFT 30,211 Microsoft External Staff

Hi @Mel ,

System.Web.Mvc.WebViewPage<TModel>.Model.get returned null

The error is because you haven't defined Model in your View.
You need to fill your model and send it to the View.
Try the following:
.cshtml

@model MVCname.Models.Your Model

Controller

public ActionResult Index()  
{  
    using (MvcDB dataBase = new MvcDB())  
    {  
  
    }  
    return View(< YourModel > );  
}

If possible, you can provide code that reproduces the problem so we can better help you troubleshoot.

Best regards,
Lan Huang

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Mel 21

Thanks for your prompt answer Lan! I did try inputting Client in the return View(); but I got this message: Client is a type which is not valid given the context.

I have set up ia Client model, ClientController and Client.cshtml view. I followed a YouTube tutorial so I'm just so stuck!

Here is the controller code:
using BasicMVCProject.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace BasicMVCProject.Controllers  
{  
    public class ClientController : Controller  
    {   
        // GET: Client  
        public ActionResult Index()  
        {  
          
            List<Client> clientList = new List<Client>();  
  
            clientList.Add(new Client { FirstName = "John", LastName = "Williams", Phone = 0421762441, Email = "******@yahoo.com" });  
            clientList.Add(new Client { FirstName = "John", LastName = "Williams", Phone = 0421762441, Email = "******@yahoo.com" });  
            clientList.Add(new Client { FirstName = "John", LastName = "Williams", Phone = 0421762441, Email = "******@yahoo.com" });  
            clientList.Add(new Client { FirstName = "John", LastName = "Williams", Phone = 0421762441, Email = "******@yahoo.com" });  
  
        return View();  
        }  
    }  
}

Here is the view:

...continued

Lan Huang-MSFT 30,211 Reputation points Microsoft External Staff

2022-09-26T01:59:26.327+00:00
Hi @Mel ,
According to your code, what you need to return is clientList.

return View(clientList);

Best regards,
Lan Huang
Mel 21 Reputation points

2022-09-26T02:10:21.067+00:00

That worked! Thank you so much for your help :)

Jinesh Prajapati 0

its not working.

@model IEnumerable<Crude1.Models.Employee>


<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
</head>
<body>
    <p>
        @Html.ActionLink("Create New", "Create")
    </p>
    <table class="table">
        <tr>
            <th>
                @Html.DisplayNameFor(model => model.Name)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Email)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Dob)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Gender)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Contact)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.City)
            </th>
            <th>
                @Html.DisplayNameFor(model => model.Address)
            </th>
            <th></th>
        </tr>
    
    @foreach (var item in Model) {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.Name)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Email)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Dob)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Gender)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Contact)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.City)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Address)
            </td>
            <td>
                @Html.ActionLink("Edit", "Edit", new { id=item.Id }) |
                @Html.ActionLink("Details", "Details", new { id=item.Id }) |
                @Html.ActionLink("Delete", "Delete", new { id=item.Id })
            </td>
        </tr>
    }
    
    </table>
</body>
</html>

---Model---

namespace Crude1.Models
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;

    public partial class Employee
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Email { get; set; }
        public DateTime Dob { get; set; }
        public string Gender { get; set; }
        public string Contact { get; set; }
        public string City { get; set; }
        public string Address { get; set; }
    }
}

---Controoller---

using Crude1.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
namespace Crude1.Controllers
{
    public class HomeController : Controller
    {
        // GET: Home
        [HttpGet]
        public ActionResult Index()
        {
            //using (CrudEntities dataBase = new CrudEntities())
            //{
            //}
            return View();
        }
        public ActionResult Create()
        {
            return View();
        }
        
    }
}

Capture

Anonymous

@Lan Huang-MSFT Me too need help please. Just one and I'll do the rest.
sdafdasf

// Model

{

    public int VehicleID { get; set; }

    public int VehicleTypeID { get; set; }

    public string Brand { get; set; }

    public string Model { get; set; }

    public int Capacity { get; set; } = 0;

    public bool IsActive { get; set; }

}


    // GET: Vehicle

    [AccessRights(AccessKey = "VE")]

    public ActionResult Vehicle()

    {

        DataSet tempDS = new DataSet();

        string __ConnectionString = ConfigurationManager.ConnectionStrings["MySqlConnector"].ConnectionString;

        tempDS = SelectDataSet(__ConnectionString, "SELECT * FROM vehicle WHERE IsActive = 1");

        var ds = tempDS;

        ViewBag.dataSource = ds.Tables[0];

        ViewBag.Search = true;

        return View();

    }

    [AccessRights(AccessKey = "VE")]

    public ActionResult VehicleInsert(VehicleModel model)

    {

        try

        {

            string baseSql = "INSERT INTO `vehicle` (`Brand`, `Model`, `IsActive`) VALUES (@brand, @model, @isActive);";

            Dictionary<string, object> param = new Dictionary<string, object>

            {

                { "@brand", model.Brand },

                { "@model", model.Model },

                { "@isActive", model.IsActive }

            };

            DB2.ExecuteNonQueryEscape(baseSql, param);

        }

        catch (Exception ex)

        {

            return Json(new { success = false, error = ex.Message });

        }

        return Json(new { success = true });

    }

    [HttpGet]

    [AccessRights(AccessKey = "VE")]

    public ActionResult EditVehicle(int ID)

    {

        DataSet tempDS = new DataSet();

        string __ConnectionString = ConfigurationManager.ConnectionStrings["MySqlConnector"].ConnectionString;

        string query = $"SELECT * FROM vehicle WHERE VehicleID=" + ID + ";";

        tempDS = SelectDataSet(__ConnectionString, query);

        var ds = tempDS;

        VehicleModel model = new VehicleModel();

        foreach (DataRow row in ds.Tables[0].Rows)

        {

            model = (DBObjectMapper.Map<VehicleModel>(row));

        }

        return PartialView(model);

    }

    [AccessRights(AccessKey = "VE")]

    public ActionResult VehicleUpdate(VehicleModel model)

    {

        try

        {

            if (model.VehicleID != 0)

            {

                string baseSql = "UPDATE `vehicle` SET `Brand` = @brand, `Model` = @model, `IsActive` = @isActive WHERE `VehicleID` = @vehicleId";

                Dictionary<string, object> param = new Dictionary<string, object>

                {

                    { "@brand", model.Brand },

                    { "@model", model.Model },

                    { "@isActive", model.IsActive }

                };

                DB2.ExecuteNonQueryEscape(baseSql, param);

            }

            else

            {

                return Json(new { success = false, error = "ID cannot be null" });

            }

        }

        catch (Exception ex)

        {

            return Json(new { success = false, error = ex.Message });

        }

        return Json(new { success = true });

    }

    [AccessRights(AccessKey = "VE")]

    public ActionResult VehicleDelete(VehicleModel model)

    {

        try

        {

            if (model.VehicleID != 0)

            {

                string baseSql = "UPDATE `vehicle` SET `IsActive` = @isActive WHERE `VehicleID` = @vehicleId;";

                Dictionary<string, object> param = new Dictionary<string, object>()

                {

                    { "@vehicleId", model.VehicleID },

                    { "@isActive", 0 },

                };

                DB2.ExecuteQueryScalarEscape(baseSql, param);

            }

            else

            {

                return Json(new { success = false, error = "ID cannot be null" });

            }

        }

        catch (Exception ex)

        {

            return Json(new { success = false, error = ex.Message });

        }

        return Json(new { success = true });

    }

Lan Huang-MSFT 30,211 Reputation points Microsoft External Staff

2024-06-21T09:31:45.6266667+00:00

Hi @Naveinthiran ,

This thread is too old. If you have any questions, please post a new thread. Thank you.

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System.NullReferenceException: 'Object reference not set to an instance of an object.' when trying to run new View.

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