Develop Reference

Partial view data doesn't get saved in ASP.NET Core MVC

I create class Project in project class I define technology and another i define Class Technology I seed data in technology and after that i create dropdown list in Project Create view using a partial view and when I save data the technology can not be saved
public class Project
{
public int ProjectId { get; set; }
[StringLength(60, MinimumLength = 3)]
public string? ProjectName { get; set; }
public string? Description { get; set; }
public DateTime Start { get; set; }
public DateTime? End { get; set; }
public string? ProjectHead { get; set; }
public string? Status { get; set; }
public string? Technology { get; set; }
}
public class Technology
{
public int TechnologyId { get; set; }
public string? TechnologyName { get; set; }
}
This is my controller:
public async Task<IActionResult> Create([Bind("ProjectId,ProjectName,Description,Start,End,ProjectHead,Status,Technology")] Project project)
{
if (ModelState.IsValid)
{
_context.Add(project);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
return View(project);
}
This is my view of project create:
<div class="row">
<partial name="_Technologypartial" />
</div>
technology Patial
#model TeamManagement.Models.Technology
<div class="row">
<div class="form-group col-md-6">
<label>Technology</label>
<br />
<select asp-for="TechnologyId" class="form-control" asp-items="#(new SelectList(ViewBag.Technology,"TechnologyId","TechnologyName"))">
</select>
</div>
</div>
EDIT
View
<div class="row">
<partial name="_Technologypartial" model="#Model.technology" />
</div>
Controller
{
var list = _context.Technology.ToList();
List<SelectListItem> dropdown = new List<SelectListItem>();
foreach (var item in list)
{
dropdown.Add(new SelectListItem()
{
Text = item.TechnologyName,
Value = item.TechnologyId.ToString()
});
}
PartialViewData model = new PartialViewData();
ViewBag.Technology = dropdown;
return View(model);
}
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create(PartialViewData model)
{
if (ModelState.IsValid)
{
Project project = new Project()
{
ProjectId = model.project.ProjectId,
ProjectName = model.project.ProjectName,
Description = model.project.Description,
Start = model.project.Start,
End = model.project.End,
ProjectHead = model.project.ProjectHead,
Status = model.project.Status,
Technology = model.technology.TechnologyId.ToString()
};
_context.Add(project);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
return View(model);
}

When you select an option in Partial View, After submiting the form, You want save the value of option. I suggest you to use ViewModel to achieve it. Refer to this simple demo:
I simplified your class for testing convenience.
public class Project
{
public string Name { get; set; }
public string? Technology { get; set; }
}
public class Technology
{
public int TechnologyId { get; set; }
public string? TechnologyName { get; set; }
}
Create a View model to pass the value.
public class PartialViewData
{
public PartialViewData()
{
project = new Project();
technology = new Technology();
}
public Project project { get; set; }
public Technology technology { get; set; }
}
DbContext
public class MvcMovieContext : DbContext
{
public MvcMovieContext(DbContextOptions<MvcMovieContext> options) : base(options)
{
}
public DbSet<Technology> technology { get; set; }
}
Controller
public class HomeController : Controller
{
private readonly MvcMovieContext _context;
public HomeController(MvcMovieContext context)
{
_context = context;
}
public IActionResult Index()
{
return View();
}
public IActionResult Privacy()
{
var list = _context.technology.ToList();
List<SelectListItem> dropdown = new List<SelectListItem>();
foreach(var item in list)
{
dropdown.Add(new SelectListItem()
{
Text = item.TechnologyName,
Value = item.TechnologyId.ToString()
}) ;
}
PartialViewData model = new PartialViewData();
ViewBag.Technology = dropdown;
return View(model);
}
[HttpPost]
public IActionResult Privacy(PartialViewData model)
{
Project project = new Project()
{
Name = model.project.Name,
Technology = model.technology.TechnologyId.ToString()
};
//......
return View();
}
}
View
#model PartialViewData
<form method="post">
<input asp-for="#Model.project.Name" />
<div class="row">
<partial name="_Technologypartial" model="#Model.technology" />
</div>
<button type="submit">submit</button>
</form>
_Technologypartial
#model Technology
<div class="row">
<div class="form-group col-md-6">
<label>Technology</label>
<br />
<select name="technology.TechnologyId" class="form-control" asp-items=#ViewBag.Technology>
</select>
</div>
</div>
Demo:
Edit=================
public IActionResult Create()
{
var list = _context.technology.ToList();
List<SelectListItem> dropdown = new List<SelectListItem>();
foreach(var item in list)
{
dropdown.Add(new SelectListItem()
{
Text = item.TechnologyName,
Value = item.TechnologyId.ToString()
}) ;
}
PartialViewData model = new PartialViewData();
ViewBag.Technology = dropdown;
return View(model);
}
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create(PartialViewData model)
{
if (ModelState.IsValid)
{
//change here
var name = _context.Technology.Where(x => x.TechnologyId == model.technology.TechnologyId).Select(x => x.TechnologyName).FirstOrDefault();
Project project = new Project()
{
ProjectId = model.project.ProjectId,
ProjectName = model.project.ProjectName,
Description = model.project.Description,
Start = model.project.Start,
End = model.project.End,
ProjectHead = model.project.ProjectHead,
Status = model.project.Status,
//change here
Technology = name
};
_context.Add(project);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
return View(model);
}
View
#model PartialViewData
<div class="row">
<partial name="_Technologypartial" model="#Model.technology" />
</div>
_Technologypartial
#model Technology
<div class="row">
<div class="form-group col-md-6">
<label>Technology</label>
<br />
<select name="technology.TechnologyId" class="form-control" asp-items=#ViewBag.Technology>
</select>
</div>
</div>

Unable to add the value from dropdownlist to database

I created a form to store information about the customers and his membership type. For that I am using the drop down list to hold values for membership types. But on submitting the form, the value(Id) for membership type isnt added to database
//Model Membership Types
public int Id { get; set; }
public string Name { get; set; }
//ViewModel NewCustomerviewModel
public IEnumerable<MembershipTypes> MembershipTypes { get; set; }
public Customers Customers{ get; set; }
//Controler CustomerController
public IActionResult Index()
{
var customers = _context.Customers.Include(c => c.MembershipTypes).ToList();
return View(customers);
}
[HttpPost]// Create is the aciton for Submit Button
public IActionResult Create(Customers customers)
{
_context.Customers.Add(customers);
_context.SaveChanges();
return RedirectToAction("Index", "Customers");
}
//View Model
#model Wes.ViewModels.NewCustomerviewModel;
#Html.DropDownListFor(m => m.Customers.MembershipTypes, new SelectList(Model.MembershipTypes, "Id", "Name"),"Select Membership Type", new { #class = "form-control" })
When the Form is Submitted, it should add all the values to the database including the value of Drop Down List Membership Types

You could try doing it this way:
//model
public int Id { get; set; }
public string Name { get; set; }
public enum MembershipTypes
{
Type1,
Type2,
Type3
}
public MembershipTypes _membershipTypes {get; set; }
//controller
[HttpPost]
public IActionResult Create([Bind("Id","Name","_membershipTypes")] Customers customers)
{
if (ModelState.IsValid)
{
_context.Add(customers);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
Return View(customers);
}
//view
<div class="row">
<div class="col-md-6">
<form asp-action="Create">
<div class="form-group">
<label asp-for="Name" class="control-label"></label>
<input asp-for="Name" class="form-control" />
<span asp-validation-for="Name" class="text-danger"></span>
</div>
<div class="form-group">
#Html.DropDownList("_membershipTypes",
new SelectList(Enum.GetValues(typeof(MembershipTypes))),
"Select membership type",
new { #class = "form-control" })
</div>
<input type="submit" value="Submit!" />
</form>
</div>
</div>

You need to show more about the relationships(one-to-one,one-to-many) of your models.
The parameters of your post action need to correspond with the model of your view,use NewCustomerviewModel instead of Customers.
The dropdownlist shows the type of name and pass id as value to action, so your asp-for of dropdown list needs to be set for an id or id list.
Refer to my demo which pass id list of MembershipTypes to action using multiple select.
1.My ViewModel NewCustomerviewModel,
public class MembershipTypes
{
[Key]
public int Id { get; set; }
public string Name { get; set; }
}
public class NewCustomerviewModel
{
public int[] SelectMembershipTypesId { get; set; }
public Customers Customers { get; set; }
}
public class Customers
{
[Key]
public int Id { get; set; }
public string Name { get; set; }
public IEnumerable<MembershipTypes> MembershipTypes { get; set; }
}
2.Create GET action
public IActionResult Create()
{
var model = new NewCustomerviewModel()
{
Customers = new Customers()
{
MembershipTypes = _context.MembershipTypes.ToList()
},
};
return View(model);
}
3.Create POST action
[HttpPost]
public async Task<IActionResult> Create(NewCustomerviewModel viewmodel)
{
if (ModelState.IsValid)
{
viewmodel.Customers.MembershipTypes= _context.MembershipTypes
.Where(m =>viewmodel.SelectMembershipTypesId.Contains(m.Id))
.ToList();
_context.Add(viewmodel.Customers);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
return View(viewmodel);
}
4. Create View
#Html.DropDownListFor(m => m.SelectMembershipTypesId,
new SelectList(Model.Customers.MembershipTypes, "Id", "Name"), "Select Membership Type",
new { #class = "form-control", #multiple = "multiple" })

Pass model value from view to controller?

How I can pass data from view to controller? Please explain how can I pass ID to AAA?
I have model:
public class ABCDE
{
public int ID { get; set; }
public string Name { get; set; }
public int Surname { get; set; }
public List<SelectListItem> MMM { get; set; }
}
My view:
#model IList<Jednoslad.Models.ABCDE>
#{
ViewBag.Title = "title";
Layout = "~/Views/Layout/_Layout.cshtml";
}
#foreach (var m in Model)
{
using (Html.BeginForm("AAA", "BBB"))
{
<div class="moto">
<h1>#m.ID</h1>
<h2>#m.Name</h2>
<input type="submit" name="model" value="AAA"/>
</div>
}
}
My controller:
[HttpPost]
public ActionResult AAA(ABCDE model)
{
return View();
}

Use Html.EditorFor()
using (Html.BeginForm("AAA", "BBB"))
{
<div class="moto">
<h1>#Html.EditorFor(m => m.ID)</hi>
<h2>#Html.EditorFor(m =>m.Name)</h2>
<input type="submit" name="model" value="AAA"/>
</div>
}

Insert succeeds but the inserted value shows NULL in the back end ms sql database

I have a simple mvc5 code first application, It has a ms SQL database in the back-end and and a form in the front-end.
While I insert into database via the front end form, it does not generate any error, everything seems OK but when i check the back end database table, then all values in the newly inserted row are showing as NULL.
This is my code for model:
public class students
{
public int Id { get; set; }
[Display(Name = "Name")]
public string st_name { get; set; }
[Display(Name = "Father's Name")]
public string st_father_name { get; set; }
public string st_contact { get; set; }
}
This is the View Model class:
public class AddStudentViewModel
{
public students stdntss { get; set; }
}
This is the controller:
public ActionResult Index()
{
var std = _context.stdnts;
if (std==null)
{
return Content("Nothing Found");
}
return View(std);
}
public ActionResult AddStudent()
{
return View();
}
[HttpPost]
public ActionResult Insert(students st)
{
_context.stdnts.Add(st);
_context.SaveChanges();
return RedirectToAction("Index","Students");
}
And finally this is the view:
#model school2.ViewModels.AddStudentViewModel
#{
ViewBag.Title = "AddStudent";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<h2>New student's registration form</h2>
#using (Html.BeginForm("Insert","Students"))
{
<div class="form-group">
#Html.LabelFor(m=> m.stdntss.st_name)
#Html.TextBoxFor(m=> m.stdntss.st_name, new { #class="form-control"})
</div>
<div class="form-group">
#Html.LabelFor(m => m.stdntss.st_father_name)
#Html.TextBoxFor(m => m.stdntss.st_father_name, new { #class = "form-control" })
</div>
<div class="form-group">
#Html.LabelFor(m => m.stdntss.st_contact)
#Html.TextBoxFor(m => m.stdntss.st_contact, new { #class = "form-control" })
</div>
<button type="submit" class="btn btn-primary">Save</button>
}
Kindly assist me if anyone has any clue?

One way to solve this is to change the POST method to accept the same model as the view.
try changing
public ActionResult Insert(students st)
{
_context.stdnts.Add(st);
_context.SaveChanges();
return RedirectToAction("Index","Students");
}
to
public ActionResult Insert(AddStudentViewModel st)
{
_context.stdnts.Add(st.stdntss );
_context.SaveChanges();
return RedirectToAction("Index","Students");
}
or changing the model of the form to simply be student.

I think that change #Html.TextBoxFor(model=> model.stdntss.st_name, new { #class="form-control"}). because call Model, #model school2.ViewModels.AddStudentViewModel . Variable default Model.

How to save changes to a view model in C#?

I am currently reading values in a configuration file and setting the values to a view model. I am displaying them on the UI in textboxes. I want the user to be able to edit/change the value in the textbox and be able to hit a save button and for the changes to be saved to the view model and the configuration file. I understand there needs to be some type of Get/Post method in the controller but I'm not entirely sure how the controller should look. I am not connecting it to a database at all.
View:
#using (Html.BeginForm())
{
<fieldset>
<div class="row">
<div class="col-md-1">Logging Directory:</div>
<div class="col-md-2">#Html.EditorFor(model => Model.loggingDirectory)</div>
<div class="col-md-1">Archive Directory:</div>
<div class="col-md-2">#Html.EditorFor(model => Model.archiveDirectory)</div>
<div class="col-md-1">Time Between Alarms:</div>
<div class="col-md-2">#Html.EditorFor(model => Model.timeBetweenAlarms)</div>
<div class="col-md-1">Time to Archive Logs:</div>
<div class="col-md-2">#Html.EditorFor(model => Model.timeToArchive)</div>
<div class="col-md-1">Situator IP:</div>
<div class="col-md-2">#Html.EditorFor(model => Model.situatorIP)</div>
<div class="col-md-1 ">Situator Port:</div>
<div class="col-md-2 ">#Html.EditorFor(model => Model.situatorPort)</div>
<div class="col-md-1 ">Clean Up:</div>
<div class="col-md-2 ">#Html.EditorFor(model => Model.timeToCleanUp)</div>
<div class="col-md-1 ">Coorelation Zone:</div>
<div class="col-md-2">#Html.EditorFor(model => Model.coorelationZone)</div>
</div>
<div class="row submitButton">
<button class="btn btn-primary" type="submit">Save</button>
</div>
</fieldset>
}
View Model
public class ConfigurationViewModel
{
public string loggingDirectory { get; set; }
public string archiveDirectory { get; set; }
public string situatorIP { get; set; }
public string situatorPort { get; set; }
public string timeBetweenAlarms { get; set; }
public string timeToArchive { get; set; }
public string sightlogixIP { get; set; }
public string timeToCleanUp { get; set; }
public string coorelationZone { get; set; }
}
Controller:
public ActionResult Index()
{
ConfigurationViewModel cvm = new ConfigurationViewModel();
cvm.loggingDirectory = ConfigurationManager.AppSettings["loggingDirectoryPath"];
cvm.archiveDirectory = ConfigurationManager.AppSettings["archiveDirectoryPath"];
cvm.situatorIP = ConfigurationManager.AppSettings["SituatorIP"];
cvm.situatorPort = ConfigurationManager.AppSettings["SituatorPort"];
cvm.timeBetweenAlarms = ConfigurationManager.AppSettings["TimeIncrementBetweenalarmsInSeconds"];
cvm.timeToArchive = ConfigurationManager.AppSettings["timeIncrementForArchivingLogFilesInHours"];
cvm.sightlogixIP = ConfigurationManager.AppSettings["SightLogixIP"];
cvm.timeToCleanUp = ConfigurationManager.AppSettings["timeIncrementForCleaningUp"];
cvm.coorelationZone = ConfigurationManager.AppSettings["correlationZoneLengthInFeet"];
return View(cvm);
}
[HttpGet]
public ActionResult Edit()
{
return;
}
[HttpPost]
public ActionResult Edit()
{
return;
}

Pass view model in Get Edit method
[HttpGet]
public ActionResult Edit()
{
ConfigurationViewModel cvm = new ConfigurationViewModel();
cvm.loggingDirectory = ConfigurationManager.AppSettings["loggingDirectoryPath"];
cvm.archiveDirectory = ConfigurationManager.AppSettings["archiveDirectoryPath"];
cvm.situatorIP = ConfigurationManager.AppSettings["SituatorIP"];
cvm.situatorPort = ConfigurationManager.AppSettings["SituatorPort"];
//...
return View(cvm);
}
Send updated view model to post edit method and perform action on it
[HttpPost]
public ActionResult Edit(ConfigurationViewModel cvm)
{
ConfigurationManager.AppSettings["archiveDirectoryPath"] = cvm.archiveDirectory;
ConfigurationManager.AppSettings["SituatorIP"] = cvm.situatorIP;
ConfigurationManager.AppSettings["SituatorPort"]= cvm.situatorPort;
//...
return View(cvm);
}
And your razor view which will submit updated data to your Post Edit method
#using (Html.BeginForm("Edit", "Your controller", FormMethod.Post))
{
....
}