Develop Reference

Why is the DepartmentID value not being properly bound to the view model's property?

Not sure why but the for some reason the view model is not binding the DepartmentId when I hit the submit button, I get an error:
Value cannot be null.
Parameter name: value
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Not sure which value is being null as the code does not break, rather after hitting the submit button that is the message that is being displayed.
I'm assuming it's the departmentId that's not being properly bound to the DepartmentID property in CoursePreReqViewModel.
Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: value
View:
#using (Html.BeginForm("Catalog", "Courses", FormMethod.Post, new { #class = "pure-form pure-form-aligned" }))
{
#Html.AntiForgeryToken()
<div class="row">
<div class="col">
<input id="myInput" class="form-control" type="text" placeholder="Search..">
</div>
<div class="col">
#Html.LabelFor(model => model.DepartmentId, htmlAttributes: new { #class = "control-label col-md-2" })
#Html.DropDownListFor(model => model.DepartmentId, Model.DepartmentList, "Department", new { #class = "form-control required", id = "department-list" })
#Html.ValidationMessageFor(model => model.DepartmentId)
</div>
<div class="col">
<button type="submit" class="btn btn-success">Submit</button>
</div>
</div>
}
Controller:
[HttpPost]
public ActionResult Catalog(CoursePreReqViewModel viewModel)
{
DepartmentRepo dRepo;
CoursesRepo cRepo;
MajorPreRequisitesRepo reqRepo;
using (context)
{
dRepo = new DepartmentRepo(context);
cRepo = new CoursesRepo(context);
viewModel.PopulateDepermentSelectList(dRepo.GetAllDepartments());
reqRepo = new MajorPreRequisitesRepo(context);
viewModel.Courses = cRepo.GetAllCoursesAndPreReqsByDepartment(viewModel.DepartmentId);
}
return View(viewModel);
}
View model:
public class CoursePreReqViewModel
{
[Required]
[Display(Name = "")]
public int DepartmentId { get; set; }
public IList<Course> Courses { get; set; }
public IList<MajorPreRequisite> CoursesAndPreReqs { get; set; }
[Display(Name = "Department: ")]
public IList<Department> Departments { get; set; }
public CoursePreReqViewModel() { }
public SelectList DepartmentList
{
get
{
return new SelectList(Departments, "Id", "Name");
}
}
public void PopulateDepartmentSelectList(IList<Department> populatedDepartments)
{
Departments = populatedDepartments;
}
}

Sarthak here is another answer: this is the asp.net mvc fiddler https://dotnetfiddle.net/ARdtvr
!!!Display Name needs to be a value!!!

I can help you keep the code you have, and answer your question.
controller/classes:
public class Course
{
public int CourseId { get; set; }
}
public class MajorPreRequisite
{
public int MajorPreRequisiteId { get; set; }
}
public class Department
{
public int Id { get; set; }
public string Name { get; set; }
}
public class CoursePreReqViewModel
{
//Make sure to comment this out -or- put this field in view
//try this first with your code, before you change code eg using a dictionary
//[Required]
//[Display(Name = "")]
public int DepartmentId { get; set; }
public IList<Course> Courses { get; set; }
public IList<MajorPreRequisite> CoursesAndPreReqs { get; set; }
[Display(Name = "Department: ")]
public IList<Department> Departments { get; set; }
public CoursePreReqViewModel() { }
public Dictionary<string, string> DepartmentList { get; set; }
public void GetAllCoursesAndPreReqsByDepartment(IList<Course> populateCourses)
{
Courses = populateCourses;
}
}
public class HomeController : Controller
{
[HttpPost]
public ActionResult Catalog(CoursePreReqViewModel viewModel)
{
//Put a breakpoint herre to see departmentid of user choice
return View();
}
public ActionResult Index11()
{
CoursePreReqViewModel viewModel = new CoursePreReqViewModel();
Dictionary<string, string> depts = new Dictionary<string, string>();
depts.Add("1", "deptOne");
depts.Add("2", "deptTwo");
viewModel.DepartmentList = depts;
IList<Course> courses = new List<Course>();
courses.Add(new Course { CourseId = 1 });
courses.Add(new Course { CourseId = 2 });
viewModel.GetAllCoursesAndPreReqsByDepartment(courses);
return View(viewModel);
}
view:
#model WebApplication4what2.Controllers.CoursePreReqViewModel
#{
Layout = null;
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Index11</title>
</head>
<body>
#using (Html.BeginForm("Catalog", "Home", FormMethod.Post, new { #class = "pure-form pure-form-aligned" }))
{
<div class="row">
<div class="col">
<input id="myInput" class="form-control" type="text" placeholder="Search..">
</div>
<div class="col">
#Html.LabelFor(model => model.DepartmentId, htmlAttributes: new { #class = "control-label col-md-2" })
#Html.DropDownListFor(model => model.DepartmentId, new SelectList(Model.DepartmentList, "Key", "Value"), Model.DepartmentId)
#Html.ValidationMessageFor(model => model.DepartmentId)
</div>
<div class="col">
<button type="submit" class="btn btn-success">Submit</button>
</div>
</div>
}
</body>
</html>

How do I use same view model but for different view excluding the required properties?

I have a view model for a view AddAppointment. It has many properties of which 2 are Required (I wrote Required attribute over it).
Now I want to use the same model for another view but excluding the properties which are required but it doesn't work i.e. it's invalid.
What to do apart from writing another view model?
View Model:
public class AddBookingsViewModel
{
public string CustomerName { get; set; }
public string ContactNo { get; set; }
public string VehicleRegNo { get; set; }
public short fk_VehicleMakeID { get; set; }
public string VehicleModel { get; set; }
[Required(ErrorMessage = "Select appointment time ")]
public int fk_TimeSlotID { get; set; }
public byte fk_BookingModeID { get; set; }
public int EntryUserID { get; set; }
public int ReturnBookingID { get; set; }
[Required(ErrorMessage="Fill in the appointment date")]
[DataType(DataType.Date)]
public DateTime? AppointmentDate { get; set; }
}
View: (Where it is used)
#model ZahidCarWash.ViewModels.AddBookingsViewModel
#{
ViewBag.Title = "Add Appointment";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<!-- page banner -->
<!-- end page banner -->
#using (Html.BeginForm())
{
<!-- appointments -->
<div id="appointments" class="appointment-main-block appointment-two-main-block">
<div class="container">
<div class="row">
<div class="section text-center">
<h3 class="section-heading text-center">Get an Appointment</h3>
</div>
<div class="col-md-8 col-sm-12">
<div class="appointment-block">
<h5 class="form-heading-title"><span class="form-heading-no">1.</span>Vehicle Information</h5>
<div class="row">
<div class="col-sm-4">
<div class="dropdown">
#Html.DropDownListFor(Model => Model.fk_VehicleMakeID, new SelectList(ZahidCarWash.DAL.VehicleMakesRepository.getVehicleMakes(), "VehicleMakeID", "MakeTitle"),
new { #class = "form-control" })
</div>
</div>
<div class="col-sm-4">
#Html.EditorFor(Model => Model.VehicleModel, new { htmlAttributes = new { #class = "form-control", placeholder = "Enter Vehicle Model" } })
</div>
<div class="col-sm-4">
#Html.EditorFor(Model => Model.VehicleRegNo, new { htmlAttributes = new { #class = "form-control", placeholder = "Enter Vehicle Reg No." } })
</div>
</div>
<h5 class="form-heading-title"><span class="form-heading-no">2.</span>Contact Details</h5>
<div class="row">
<div class="col-sm-4">
#Html.EditorFor(Model => Model.CustomerName, new { htmlAttributes = new { #class = "form-control", placeholder = "Customer Name" } })
#Html.ValidationMessageFor(Model => Model.CustomerName, "", new { #class = "ErrorMessages" })
</div>
<div class="col-sm-4">
#Html.EditorFor(Model => Model.ContactNo, new { htmlAttributes = new { #class = "form-control", placeholder = "Enter Contact Number." } })
#Html.ValidationMessageFor(Model => Model.ContactNo, "", new { #class = "ErrorMessages" })
</div>
</div>
<button type="submit" class="btn btn-default pull-right">Book Now</button>
</div>
</div>
</div>
</div>
</div>
}
Controller:
public JsonResult AddManualAppointment(AddBookingsViewModel AddBookingVM)
{
if (ModelState.IsValid)
{
AddBookingVM.fk_BookingModeID = 2;
int ReturnRowsCount = BookingRep.InsertCustomerAppointments(AddBookingVM, out ReturnStatus, out ReturnMessage, out ReturnBookingID);
}
else
{
}
return Json(new { ReturnMessageJSON = ReturnMessage, ReturnStatusJSON = ReturnStatus });
}
Data is passed through ajax:
<script type="text/javascript">
//to add an appointment
$('form').submit(function (e) {
e.preventDefault();
if (!$(this).valid()) {
return;
}
var url = '#Url.Action("AddManualAppointment")';
var data = $(this).serialize();
$.post(url, data, function (response) {
if (response.ReturnStatusJSON == true) {
swal("Booked !", response.ReturnMessageJSON, "success");
$("#VehicleRegNo").val("");
$("#VehicleModel").val("");
$("#CustomerName").val("");
$("#ContactNo").val("");
}
else {
swal("Sorry !", response.ReturnMessageJSON, "error");
}
});
});
</script>
<!--End Custom Scripts-->
}

I guess the quick and dirty way is to use #Html.Hiddenfor and fill the value with a new datetime from inside your controller

You can split your view model into a version with and without the required attributes using inheritance:
public class AddBookingsViewModel
{
public string CustomerName { get; set; }
public string ContactNo { get; set; }
public string VehicleRegNo { get; set; }
public short fk_VehicleMakeID { get; set; }
public string VehicleModel { get; set; }
public byte fk_BookingModeID { get; set; }
public int EntryUserID { get; set; }
public int ReturnBookingID { get; set; }
}
public class AddBookingsViewModelWithAppointment : AddBookingsViewModel
{
[Required(ErrorMessage = "Select appointment time ")]
public int fk_TimeSlotID { get; set; }
[Required(ErrorMessage="Fill in the appointment date")]
[DataType(DataType.Date)]
public DateTime? AppointmentDate { get; set; }
}
This allows you to use the appropriate view model in your situation and still maintain compatibilty through polymorphism.
If you need the optional properties in your base class, you can make your properties virtual and apply the attribute in the derived class:
public class AddBookingsViewModel
{
public string CustomerName { get; set; }
public string ContactNo { get; set; }
public string VehicleRegNo { get; set; }
public short fk_VehicleMakeID { get; set; }
public string VehicleModel { get; set; }
public byte fk_BookingModeID { get; set; }
public int EntryUserID { get; set; }
public int ReturnBookingID { get; set; }
public virtual int fk_TimeSlotID { get; set; }
public virtual DateTime? AppointmentDate { get; set; }
}
public class AddBookingsViewModelWithAppointment : AddBookingsViewModel
{
[Required(ErrorMessage = "Select appointment time ")]
public override int fk_TimeSlotID {
get => base.fk_TimeSlotID;
set => base.fk_TimeSlotID = value;
}
[Required(ErrorMessage="Fill in the appointment date")]
[DataType(DataType.Date)]
public override DateTime? AppointmentDate {
get => base.AppointmentDate;
set => base.AppointmentDate = value;
}
}
Use the veriant that works best in your business case.

mvc multiple models in view

I am making an MVC application. I am creating a View that uses a ViewModel and also use database entities in this view passed by the controller.
Controller:
public ActionResult AddGroup(AddGroupViewModel model)
{
ClassDeclarationsDBEntities1 entities=new ClassDeclarationsDBEntities1();
return View(entities.Subjects.ToList());
}
ViewModel:
public class AddGroupViewModel
{
[Required]
[Display(Name = "Subject")]
public string subject_name { get; set; }
[Required]
[Display(Name = "Number of Groups")]
public int qty { get; set; }
}
And finally my view:
#model List<ClassDeclarationsThsesis.Classes.Subject>
#model ClassDeclarationsThsesis.Models.AddGroupViewModel
#{
ViewBag.Title = "Add Groups";
}
<h2>Add Groups to subjects</h2>
#using (Html.BeginForm("AddGroup", "Account", FormMethod.Post, new { #class = "form-horizontal", role = "form" }))
{
#Html.AntiForgeryToken()
<h4>Create new groups.</h4>
<hr />
#Html.ValidationSummary("", new { #class = "text-danger" })
<div class="form-group">
#{
List<SelectListItem> listItems1 = new List<SelectListItem>();
}
#foreach (var subject in Model)
{
listItems1.Add(new SelectListItem
{
Text = subject.name,
Value = subject.name,
Selected = true
});
}
#Html.LabelFor(m => m.subject_name, new {#class = "col-md-2 control-label"})
<div class="col-md-10">
#Html.DropDownListFor(m => m.subject_name, listItems1, new {#class = "form-control"})
</div>
</div>
<div class="form-group">
#Html.LabelFor(m => m.qty, new { #class = "col-md-2 control-label" })
<div class="col-md-10">
#Html.TextBoxFor(m => m.qty, new { #class = "form-control" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" class="btn btn-default" value="Submit" />
</div>
</div>
}
As you see, I am trying to use two models in my view. But gives an exception (well how to distinguish them). How do I combine those two models in a view?
Edit:
So I did what suggested in answer, but now I get such exception:
{"The class 'ClassDeclarationsThsesis.Models.Subject' has no parameterless constructor."}
The class looks like this:
namespace ClassDeclarationsThsesis.Models
{
using System;
using System.Collections.Generic;
public partial class Subject
{
private int v;
private int userid;
public Subject(int v, int userid, string name)
{
this.class_id = v;
this.user_id = userid;
this.name = name;
}
public int class_id { get; set; }
public int user_id { get; set; }
public string name { get; set; }
public virtual Group Group { get; set; }
public virtual Subjects_Users Subjects_Users { get; set; }
public virtual Task Task { get; set; }
}
}
How do I solve it?

Since you already have a view model, I'd use that:
#model ClassDeclarationsThsesis.Models.AddGroupViewModel
And simply add a property to that view model for the collection you also want to use:
public class AddGroupViewModel
{
[Required]
[Display(Name = "Subject")]
public string subject_name { get; set; }
[Required]
[Display(Name = "Number of Groups")]
public int qty { get; set; }
public List<Subject> Subjects { get; set; }
}
Then simply create an instance of that from your controller to send to the view:
var entities = new ClassDeclarationsDBEntities1();
var model = new AddGroupViewModel();
model.Subjects = entities.Subjects.ToList();
// set your other properties too?
return View(model);
Then in the view simply refer to the property on the Model instead of the model itself when you need that collection:
#foreach (var subject in Model.Subjects)
Basically, while you can use only one type for your model (since there's only one Model property available to the view in the framework), that type can be anything you like, even a custom view model type that you define.

c# ASP.NET MVC cannot pass model's collection field to controller [duplicate]

This question already has answers here:
Post an HTML Table to ADO.NET DataTable
(2 answers)
Closed 7 years ago.
I have a class from EF.
public partial class Customer
{
public Customer()
{
this.Customer_CustomerSpecialConcern = new HashSet<Customer_CustomerSpecialConcern>();
}
public int Id { get; set; }
public string Name { get; set; }
public string Surname { get; set; }
public string Email { get; set; }
public string Mobile { get; set; }
public virtual ICollection<Customer_CustomerSpecialConcern> Customer_CustomerSpecialConcern { get; set; }
}
When I pass the model from controller to view everything works fine (can access Customer_CustomerSpecialConcern values).
The problem is when I post back model to a controller to save the changes the property Customer_CustomerSpecialConcern is null.
Here is how I use it in view.
#foreach (var ccsc in Model.Customer_CustomerSpecialConcern)
{
<div class="form-group fields-container col-md-3">
<label class="field-label control-label col-md-10" for="">#ccsc.CustomerSpecialConcern.Title</label>
<div class="col-md-1 field-input">
#Html.EditorFor(model => ccsc.Value)
#Html.HiddenFor(model => ccsc.Value)
</div>
</div>
}
Please, I need help to get the values of this collection property to controller. Thank you.
Update - Customer_CustomerSpecialConcern class details
public partial class Customer_CustomerSpecialConcern
{
public int Id { get; set; }
public int Customer_Id { get; set; }
public int CustomerSpecialConcern_Id { get; set; }
public bool Value { get; set; }
public virtual Customer Customer { get; set; }
public virtual CustomerSpecialConcern CustomerSpecialConcern { get; set; }
}

Please try this,
#for (int i = 0; i < Model.Customer_CustomerSpecialConcern.Count(); i++)
{
<div class="form-group fields-container col-md-3">
<label class="field-label control-label col-md-10" for="">#Model.CustomerSpecialConcern[i].Title</label>
<div class="col-md-1 field-input">
#Html.EditorFor(model => model.Customer_CustomerSpecialConcern[i].Value)
#Html.HiddenFor(model => model.Customer_CustomerSpecialConcern[i].Value)
</div>
</div>
}
Check this article.
I tried your example, and this is how it looks
public ActionResult Index()
{
var customer = new Customer
{
Name = "Name",
Surname = "Surname",
Email = "email#email.com",
Mobile = "mobile...",
Customer_CustomerSpecialConcern = new List<Customer_CustomerSpecialConcern>
{
new Customer_CustomerSpecialConcern
{
Value = true
},
new Customer_CustomerSpecialConcern
{
Value = true
}
}
};
return View(customer);
}
View:
#model WebApplication1.Models.Customer
#{
ViewBag.Title = "Customer";
var customer_CustomerSpecialConcern = Model.Customer_CustomerSpecialConcern.ToList();
}
#using (Html.BeginForm())
{
#Html.AntiForgeryToken()
for (int i = 0; i < Model.Customer_CustomerSpecialConcern.Count(); i++)
{
<div class="form-group fields-container col-md-3">
<label class="field-label control-label col-md-10" for=""></label>
<div class="col-md-1 field-input">
#Html.CheckBoxFor(model => customer_CustomerSpecialConcern[i].Value)
</div>
</div>
}
<input type="submit" value="Save"/>
}

Pass a model to a partial view?

this is my partial:
#model RazorSharpBlog.Models.MarkdownTextAreaModel
<div class="wmd-panel">
<div id="wmd-button-bar-#Model.Name"></div>
#Html.TextAreaFor(m => m.Name, new { #id = "wmd-input-" + #Model.Name, #class = "wmd-input" })
</div>
<div class="wmd-panel-separator"></div>
<div id="wmd-preview-#Model.Name" class="wmd-panel wmd-preview"></div>
<div class="wmd-panel-separator"></div>
I'm trying to include it like this in my View:
#using (Html.BeginForm())
{
#Html.LabelFor(m => m.Title)
#Html.TextBoxFor(m => m.Title)
#Html.Partial("MarkdownTextArea", new { Name = "content" })
<input type="submit" value="Post" />
}
these are the model classes:
public class MarkdownTextAreaModel
{
[Required]
public string Name { get; set; }
}
public class BlogContentModel
{
[Required]
[Display(Name = "Post Title")]
public string Title { get; set; }
[Required]
[DataType(DataType.MultilineText)]
[Display(Name = "Post Content")]
public string Content { get; set; }
}
What am I doing wrong, how should I do this in order to make my partial reusable?

Your partial expects an instance of the MarkdownTextAreaModel class. So do so, instead of passing an anonymous object which would throw anyways:
#Html.Partial("MarkdownTextArea", new MarkdownTextAreaModel { Name = "content" })
Now this being said a far better solution would be to adapt your view model, so that it contains a reference to MarkdownTextAreaModel and use editor templates instead of partials in your views, just like so:
public class BlogContentModel
{
[Required]
[Display(Name = "Post Title")]
public string Title { get; set; }
[Required]
[DataType(DataType.MultilineText)]
[Display(Name = "Post Content")]
public string Content { get; set; }
public MarkdownTextAreaModel MarkDown { get; set; }
}
then of course readapt the controller serving this view so that it populates the MarkDown of your view model:
public ActionResult Foo()
{
BlogContentModel model = .... fetch this model from somewhere (a repository?)
model.MarkDown = new MarkdownTextAreaModel
{
Name = "contect"
};
return View(model);
}
and then inside your main view simply:
#using (Html.BeginForm())
{
#Html.LabelFor(m => m.Title)
#Html.TextBoxFor(m => m.Title)
#Html.EditorFor(x => x.MarkDown)
<input type="submit" value="Post" />
}
and then in order to follow standard conventions move your partial to ~/Views/YourControllerName/EditorTemplates/MarkdownTextAreaModel.cshtml and now everything will magically come into place as it should.

#using (Html.BeginForm()) {
#Html.LabelFor(m => m.Title) #Html.TextBoxFor(m => m.Title)
#Html.Partial("MarkdownTextArea", new MarkdownTextAreaModel { Name = "content" })
<input type="submit" value="Post" />
}