Debugging Model Referenced by Razor View

Question

Total newbie in ASP.Net MVC and Razor Pages.

I have a Razor View with the model referenced declared on top:

@model TestApplication.Models.Registration

How would I be able to debug the model? I've tried setting breakpoints in the model but when debugging, the breakpoints are not being hit.

Code is as follows:

Register.cshtml

@model TestApplication.Models.Registration
@{
    string labelClass = "ctrl-label col-sm-4", 
        controlSize = "col-sm-8";   
}

<div class="row">
    <div class="col-md-7 col-md-offset-2">
        <h2>@TestApplication.Resources.General.Register</h2>
        @using (Html.BeginForm("Register", "Account", FormMethod.Post, new{role = "form", @class = "form-horizontal" }))
        {
            <div class="form-group">
                <h3 class="@labelClass">
                    <small>@TestApplication.Resources.General.CreateAccount</small></h3>
            </div>

            <hr />

            <div class="form-group @Html.ValidationErrorFor(m => m.EmailAddress, "has-error has-feedback")">
                @Html.LabelFor(p => p.EmailAddress, new { @class = labelClass })
                <div class="@controlSize">
                    @Html.FormTextBoxFor(p => p.EmailAddress, new { @class = "form-control" })
                    @if (!Html.IsValid(m => m.EmailAddress))
                    { 
                        <span class="glyphicon glyphicon-remove form-control-feedback"></span>
                    }
                    <span class="hint">@TestApplication.Resources.Forms.RegisterHintEmailAddress</span>
                    @Html.ValidationMessageFor(m => m.EmailAddress, null, new { @class = "help-block" })
                </div>
            </div>

            <div class="form-group @Html.ValidationErrorFor(m => m.Username, "has-error has-feedback")">
                @Html.LabelFor(p => p.Username, new { @class = labelClass })
                <div class="@controlSize">
                    @Html.FormTextBoxFor(p => p.Username, new { @class = "form-control" })
                    @if (!Html.IsValid(m => m.Username))
                    { 
                        <span class="glyphicon glyphicon-remove form-control-feedback"></span>
                    }
                    @Html.ValidationMessageFor(m => m.Username, null, new { @class = "help-block" })
                </div>
            </div>

            <div class="form-group">
                <label class="@labelClass">@TestApplication.Resources.Forms.RegisterLabelStartService</label>
                <div class="@controlSize">

                @* I AM GETTING AN ERROR ON THIS LINE... *@
                @*@foreach(var m in Model.Services)
                {
                    <div class="radio">
                        <label>
                            @Html.RadioButtonFor(p => p.StartServiceId, m.Id)
                            @m.DisplayName
                        </label>
                    </div>
                }*@
                </div>
            </div>
        }
    </div>
</div>

Registration.cs

using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Security;
using System.Globalization;
using System.ComponentModel.DataAnnotations;
using DataAnnotationsExtensions;
using TestApplication.Resources;

namespace TestApplication.Models
{
    public class Registration
    {
        [Email(ErrorMessageResourceName = "InvalidEmail", ErrorMessageResourceType = typeof(ErrorMessages))]
        [Required(ErrorMessageResourceName = "RequiredEmailAddress", ErrorMessageResourceType = typeof(ErrorMessages))]
        [HtmlAttribute("placeholder", "PlaceholderEmailAddress", ResourceType = typeof(Forms))]
        [Display(Name = "RegisterLabelEmailAddress", ResourceType = typeof(Forms))]
        public string EmailAddress { get; set; }

        [Email(ErrorMessageResourceName = "InvalidUsername", ErrorMessageResourceType = typeof(ErrorMessages))]
        [Required(ErrorMessageResourceName = "RequiredUsername", ErrorMessageResourceType = typeof(ErrorMessages))]
        [HtmlAttribute("placeholder", "PlaceholderUsername", ResourceType = typeof(Forms))]
        [Display(Name = "RegisterLabelUsername", ResourceType = typeof(Forms))]
        [CustomValidation(typeof(Registration), "CheckIfUserExists")]
        public string Username { get; set; }

        [Display(Name = "RegisterLabelStartService", ResourceType = typeof(Forms))]
        public int StartServiceId { get; set; }

        public ReadOnlyCollection<ServicePlugin> Services { get; private set; }

        public Registration()
        {
            this.Services = new ReadOnlyCollection<ServicePlugin>(new List<ServicePlugin> { new ServicePlugin { Id = 1, DisplayName = "Mobile Services" }, new ServicePlugin { Id = 2, DisplayName = "Cable Services" } });
        }
    }
}

ServicePlugin.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace TestApplication.Models
{
    public class ServicePlugin
    {
        public int Id { get; set; }

        public string DisplayName { get; set; }
    }
}

AccountController.cs

[AllowAnonymous]
public ActionResult Register()
{
  return this.View();
}

I commented out part of the razor view (the one with ERROR) as I am not able to properly debug the class tied to this.

Specifically, I want to debug this line in Registration.cs file:

**public Registration()**

to figure out how it is being populated and being used in the view.

Appreciate any insight on doing this.

P.S. When I remove the comment on the Register.cshtml where error is happening, I am getting the error: Object Reference not set to an instance of the object.

I can set a breakpoint in this line:

@foreach(var m in Model.Services)

but Model is null and throws the error:

An exception of type 'System.NullReferenceException' occurred in appXXXX.dll but was not handled in user code.

So pretty much I think I need to understand how all of these tie up together.

Answer 1

In your Account controller you need to instantiate and then pass the Model to the view, using an overload of the View method:

[AllowAnonymous]
public ActionResult Register()
{
  return View(new Models.Registration());
}