get IEnumerable<T> in mvc post method argument - asp.net

I have one model called ProductSupplier
I am passing #model IEnumerable to my View
and showing it from view
Now when i submit the form i m not getting list of IEnumerable in my http post method. I want to know the selected supplier from user.
Below is my model
public sealed class ProductSupplier
{
public int CountryId { get; set; }
public int UserId { get; set; }
public bool IsProductSupplier { get; set; }
public string CountryName { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Email { get; set; }
}
This is my HttpGet method
public ActionResult ManageSupplier(int id)
{
var supplier = App.UsersRepo.GetSupplierForProduct(id);
return View(supplier);
}
And I am binding it via following way (U can suggest me best way I am new bee to MVC)
#model IEnumerable<ProductSupplier>
#using (Html.BeginForm("ManageSupplier", "Products", FormMethod.Post, new { role = "form") })
{ #Html.AntiForgeryToken()
foreach (var item in Model)
{
<div class="checkbox">
<label>
#Html.CheckBoxFor(x => item.IsProductSupplier, new { id = item.Email }) #item.FirstName #item.LastName (#item.Email)
</label>
</div>
}
}
And finally my HttpPost method
[HttpPost]
public ActionResult ManageSupplier(IEnumerable<ProductSupplier> obj)
{ // I m getting obj null in my argument
//I want to Get selected id from obj and want to pass in selectedSupplier
var returnVal = App.ProductRepo.AssigneSupplierForProduct(productId, selectedSupplier);
return Json(new { success = true }, JsonRequestBehavior.DenyGet);
}
can anyone suggest me where i m making mistake.
I am new to MVC any kind of suggestion highly appreciated.
Thank you in advance.

Firstable u cant do it like this.One way to do that is something like this.Here is the basic step how u do that.
1-assign for all checkbox ,checkbox change event with the unique id.
(take a look at here)
2-Cretae a jquery object and store the data when ever the checkbox clicked ,via versa
var ListProductSuppliers ={ {ProductSupplier_info_here },{ProductSupplier_info_here } };
3-later via ajax request,serilize this object(ListProductSuppliers ) and send to your method
4-on server side deserilize this to the IEnumerable<ProductSupplier>
5 later do it whatever u want with those selected suppliars

Related

Populate a select list ASP.NET Core MVC

I'm busy with an ASP.NET Core MVC application, and I'm trying to populate a drop down list. I've created a view model and I have added a method to my StoresController that returns a list of stores that I want to display in a dropdown. I've been working off some online tutorials as I'm very new to asp.
View model:
public class StoreListViewModel
{
public List<StoreList> StoreList { get; set; } = new List<StoreList>();
}
public class StoreList
{
public string StoreId { get; set; } = null!;
public string StoreName { get; set; } = null!;
}
StoresController:
public IActionResult LoadStoreList()
{
if (ModelState.IsValid)
{
var storeList = new StoreListViewModel().StoreList.Select
(x => new SelectListItem { Value = x.StoreId, Text = x.StoreName }).ToList();
ViewBag.Stores = storeList;
}
return NotFound();
}
I'm trying to use ViewBag to call my LoadStoreList() method.
<select name="storeList" class="form-control" asp-items="#(new SelectList(ViewBag.Stores, "Value", "Text"))"></select>
When I load my page I get the following error
Value cannot be null. (Parameter 'items')
The page I need the dropdown list on is my CreateUser.cshtml which is bound to my UserModel and has a UsersController. The method I have created for listing the stores is in my StoresController which is bound to my StoresModel. So I'm not sure if that's causing the issue.
I've been battling with this for days, if someone could help me get this working or show me a better method, that would be great.
*Edit
The UserIndex() method is the first method that fires when my users page opens, do I call the LoadStoreList() method from there ?
UserController
public async Task<IActionResult> UsersIndex()
{
return _context.UsersView != null ?
View(await _context.UsersView.ToListAsync()) :
Problem("Entity set 'ApplicationDbContext.Users' is null.");
}
I'm trying to use ViewBag to call my LoadStoreList() method.
ViewBag cannot be used to call any method. You just need set value for ViewBag in the method which renders your show dropdownlist's page.
From your description, you said the page you need the dropdown list on is CreateUser.cshtml. Assume that you render the CreateUser.cshtml page by using CreateUser action.
CreateUser.cshtml:
<select name="storeList" class="form-control" asp-items="#(new SelectList(ViewBag.Stores, "Value", "Text"))"></select>
Controller:
public class YourController : Controller
{
private readonly YourDbcontext _context;
public YourController(YourDbcontext context)
{
_context = context;
}
[HttpGet]
public IActionResult CreateUser()
{
var storeList = _context.StoreLists.Select
(x => new SelectListItem { Value = x.StoreId , Text = x.StoreName }).ToList();
ViewBag.Stores = storeList;
return View();
}
}
YourDbcontext should be something like:
public class YourDbcontext: DbContext
{
public YourDbcontext(DbContextOptions<MvcProjContext> options)
: base(options)
{
}
public DbSet<StoreList> StoreLists{ get; set; }
}
Dont use viewbag for storing list data. Make your view page model including List, for example:
public class UserCreationViewModel{
public int Id{ get; set; }
public string Name { get; set; }
// Any other properties....
public List<StoreList> StoreList { get; set; }
}
in your controller YourController:
[HttpGet]
public IActionResult CreateUser()
{
var storeList = new StoreListViewModel().StoreList.Select
(x => new SelectListItem { Value = x.StoreId, Text = x.StoreName }).ToList();
UserCreationViewModel model=new UserCreationViewModel{
StoreList = storeList
};
return View("createUserViewName", model);
}
in createUserViewName:
#Html.DropDownList("StoreId", new SelectList(Model.StoreList, "StoreId", "StoreName"), "Select", new { #class = "form-control" })
or
<select class="form-control" asp-for="#Model.StoreId" asp-items="#(new SelectList(Model.StoreList, "StoreId", "StoreName"))">
<option value="-1">Select</option>
</select>

DropdownList value doesnt add to database

I can display the values from my database both in a dropdownlist and where the value is needed.
But I can't get the value from the dropdownlist to my database while creating something. it's getting null.
I've tried some solutions from s.o.f but they didnt't work.
Models 1:
public class Kategori
{
[Key]
public int KategoriID { get; set; }
public string Namn { get; set; }
}
Models 2:
public class Inlägg
{
[Key]
public int InläggsID { get; set; }
public Kategori Kategori { get; set; }
}
Controller:
// POST: Inlägg/Create
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create([Bind("Titel,Text,Kategori.Namn")] Inlägg inlägg)
//The Kategori is getting null
{
if (ModelState.IsValid)
{
inlägg.Datum = DateTime.Now;
_context.Add(inlägg);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
return View(inlägg);
}
View:
#Html.DropDownList("Kategori", null, htmlAttributes: new { #class = "form-control" })
I've tried using SelectItemList, select with options values, having a SelectItem inside Models class also a "public Kategori List" inside Inlägg.
Don't really know how to solve this. I've just tried 8 hours today, and 2 hours yesterday.
How can I get the value that the user choosen in the dropdownlist instead of getting null? Tell me if I need to send more codes :-)
You should change it;
#Html.DropDownList("Kategori", null, htmlAttributes: new { #class = "form-control" })
to
#Html.DropDownList("SelectedCategory", ViewData["Kategori"] as SelectList, htmlAttributes: new { #class = "form-control" })
The selected dropdown element is passed to serverside as SelectedCategory.
Also, I strongly suggest you to use Model classes instead of ViewData to carry data between controller and view.
You need to add another property for the foreign key value. Since your other related entity class name is Kategori, you may name this new property KategoriId so that it matches the convention for the foreign key property names.
public class Inlagg
{
[Key]
public int InläggsID { get; set; }
public string Titel { get; set; }
public string Text { get; set; }
public DateTime Datum { get; set; }
public virtual Kategori Kategori { get; set; }
public int? KategoriId { set;get;} // This is the new property
}
Now in your form inside your view, make sure the select element rendered by the DropDownList helper has the same name attribute value as the new property name (check the view source of the page)
#Html.DropDownList("KategoriId", ViewData["Kategori"] as SelectList)
Now finally, make sure you include this new input name/property name inside the Bind attributes Include list so that the model binder will bind that.
public async Task<IActionResult> Create([Bind(Include="Titel,Text,KategoriId")]
Inlagg inlagg)
{
// to do : your code for saving and returning something
}
Another option is to use a view model with only needed properties, instead of using the Bind attribute with your entity class

Unusual behavior DropDownList MVC 5

I managed to populate DropDownList with value from a Database in ASP.NET MVC 5. My goal is to assing one of the dropDownList's value to a specific model, and send it back to the Database. So, if i leave the default value in the dropdownlist, the data in SQL server is null, which is Okay, but if I choose an option, I get an error :
Exception thrown: 'System.InvalidOperationException' in System.Web.Mvc.dll ("There is no ViewData item of type 'IEnumerable' that has the key 'Status'."). I tried everything so far and i am opened for suggestions. Thank you !!!
In Controller :
ViewBag.Status = new SelectList(db.Status, "Id", "Name");
in View
#Html.DropDownList("Status","Select status...")
In Controller so far..
public ActionResult Index()
{
return View();
}
[HttpGet]
public ActionResult Apply(ViewModelVM vm,int x=0)
{
myDb db = new myDb();
ViewBag.SocialStatus = new SelectList(db.SocialStatuses, "Id", "StatusDescription");
return View();
}
[HttpPost]
public ActionResult Apply(ViewModelVM vm)
{
if (ModelState.IsValid)
{
using (myDb db = new myDb())
{
var personalinfo = new PersonalInformation()
{
FirstName = vm.PersonalInformation.FirstName,
LastName = vm.PersonalInformation.LastName,
Birthdate = vm.PersonalInformation.Birthdate,
SocialStatus = vm.SocialStatus
};
ViewBag.SocialStatus = new SelectList(db.SocialStatuses, "Id", "StatusDescription");
db.PersonalInformations.Add(personalinfo);
db.SaveChanges();
}
return View("Success");
}
return View();
}
The model:
public partial class Status
{
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
public SocialStatus()
{
PersonalInformations = new HashSet<PersonalInformation>();
}
public int Id { get; set; }
[StringLength(20)]
public string StatusDescription { get; set; }
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
public virtual ICollection<PersonalInformation> PersonalInformations { get; set; }
}
}
The ViewModel:
public class ViewModelVM
{
...
public Status SocialStatus { set; get; }
...
}
Firstly your using a view model so include a property in your view model for the SelectList
public IEnumerable<SelectListItem> StatusList { get; set; }
Next remove the parameter for the model from the GET method (and since you don't appear to be using the value of x, that should be removed also)
[HttpGet]
public ActionResult Apply(ViewModelVM vm,int x=0)
{
myDb db = new myDb();
ViewModelVM model = new ViewModelVM()
{
StatusList = new SelectList(db.SocialStatuses, "Id", "StatusDescription");
};
return View(model); // return the model to the view
}
Next, your dropdown is binding to a property named Status but your view model does not contain a property named status (its SocialStatus) and SocialStatus is a complex object and you cannot bind a <select> to a complex object (a <select> only posts back a single value (or array or values in the case of <select multiple>).
In addition, because your view model contains a property which is a complex object with validation attributes on its properties, ModelState will always be invalid because you do not post back a value for StatusDescription. As a result you always return the view in the POST method, and because you have not reassigned ViewBag.Status = ...., it is null, hence the error.
Remove property public Status SocialStatus { set; get; } and include
[Display(Name = "Social Status")]
[Required(ErrorMessage = "Please select a status")]
public int SocialStatus { get; set; }
an then in the view, strongly bind to your model using
#Html.LabelFor(m => m.SocialStatus)
#Html.DropDownListFor(m => m.SocialStatus, Model.StatusList, "-Please select-")
#Html.ValidationMessageFor(m => m.SocialStatus)
Then, in the POST method, if ModelState is invalid, populate the select list again before returning the view
if(!ModelState.IsValid)
{
model.StatusList = new SelectList(db.SocialStatuses, "Id", "StatusDescription");
return View(model);
}
// save and redirect
Finally, review What is ViewModel in MVC?.

MVC 4 - Use a different model in partial view

Please bear with my noobness, I'm super new to the MVC pattern.
What I'm trying to do
I am building a profile information page for registered users on my site. This page would list data about the user, such as date of birth, telephone number, subscription status, etc.. You get the idea. I would also like to have a form to let users change their password, email address, personal information on the same page.
My problem
The user's data comes from my controller via a passed model variable:
public ActionResult Profil()
{
var model = db.Users.First(e => e.UserName == WebSecurity.CurrentUserName);
return View(model);
}
The output looks like this in my view:
<label>Phone number: </label>
#if (Model.PhoneNumber != null)
{
#Model.PhoneNumber
}
else
{
<span class="red">You haven't set up your phone number yet. </span>
}
The form in which the user could change his info would use another model, ProfileModel. So basiccaly I need to use two models in my view, one for outputting information and one for posting data. I thought that using a partial view I can achieve this, but I get this error:
The model item passed into the dictionary is of type
'Applicense.Models.User', but this dictionary requires a model item of
type 'Applicense.Models.ProfileModel'.
Here's what my call to the partial view looks like:
#using (Html.BeginForm())
{
#Html.AntiForgeryToken()
#Html.ValidationSummary()
#Html.Partial("_ModifyProfileInfo")
}
Here's the partial view:
#model Applicense.Models.ProfileModel
<ul>
<li>
#Html.LabelFor(m => m.Email)
#Html.EditorFor(m => m.Email)
</li>
<li>
#Html.LabelFor(m => m.ConfirmEmail)
#Html.EditorFor(m => m.ConfirmEmail)
</li>
<input type="submit" value="Update e-mail" />
</ul>
And finally here's my ProfileModel:
public class ProfileModel
{
[Required]
[DataType(DataType.EmailAddress)]
[Display(Name = "New e-mail address")]
public string Email { get; set; }
[DataType(DataType.EmailAddress)]
[Display(Name = "Confirm new e-mail address")]
[Compare("Email", ErrorMessage = "The e-mail and it's confirmation field do not match.")]
public string ConfirmEmail { get; set; }
}
Am I missing something? What's the proper way to do this?
Edit:
I remade my code reflecting Nikola Mitev's answer, but now I have another problem. Here's the error I get:
Object reference not set to an instance of an object. (#Model.UserObject.LastName)
This only occurs when I'm posting the changed e-mail address values. Here's my ViewModel (ProfileModel.cs):
public class ProfileModel
{
public User UserObject { get; set; }
[Required]
[DataType(DataType.EmailAddress)]
[Display(Name = "Új e-mail cím")]
public string Email { get; set; }
[DataType(DataType.EmailAddress)]
[Display(Name = "Új e-mail cím megerősítése")]
[Compare("Email", ErrorMessage = "A két e-mail cím nem egyezik.")]
public string ConfirmEmail { get; set; }
[DataType(DataType.EmailAddress)]
[Display(Name= "E-mail cím")]
public string ReferEmail { get; set; }
}
Controller:
public ActionResult Profil()
{
var User = db.Users.First(e => e.UserName == WebSecurity.CurrentUserName);
var ProfileViewModel = new ProfileModel
{
UserObject = User
};
return View(ProfileViewModel);
}
And finally here's my user.cs model class:
[Table("UserProfile")]
public class User
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public int UserId { get; set; }
[Column("UserName")]
public string UserName { get; set; }
[Column("Email")]
[Required]
public string Email { get; set; }
[Column("FirstName")]
public string FirstName { get; set; }
[Column("LastName")]
public string LastName { get; set; }
[Column("PhoneNumber")]
public string PhoneNumber { get; set; }
... You get the idea of the rest...
I'm thinking it's happening because the model is trying to put data in each required columns into the database.
Edit2:
The httppost method of my Profil action:
[HttpPost]
[Authorize]
[ValidateAntiForgeryToken]
public ActionResult Profil(ProfileModel model)
{
if (ModelState.IsValid)
{
//insert into database
return Content("everything's good");
}
else
{
//outputs form errors
return View(model);
}
}
The best way to handle this situation is to use and pass viewModel to your Profile controller, viewModel is wrapper class for multiple objects that you want to pass to your view.
public class ProfileUserViewModel
{
public ProfileModel ProfileModelObject {get; set;}
public UserModel UserModelObject {get; set;}
}
Your controller should look like:
public ActionResult Profil()
{
var profileModel = db.Users.First(e => e.UserName == WebSecurity.CurrentUserName);
var userModel = //fetch from db.
var pmViewModel = new ProfileUserViewModel
{
ProfileModelObject = profileModel,
UserModelObject = userModel
};
return View(pmViewModel);
}
And finally your view :
#model Applicense.Models.ProfileUserViewModel
<label>Phone number: </label>
#if (Model.ProfileModelObject.PhoneNumber != null)
{
#Model.PhoneNumber
}
else
{
<span class="red">You haven't set up your phone number yet. </span>
}
There is an overload of #Html.Partial which allows you to send ViewData as defined in your controller - this is the method I generally use for partial views.
In your controller define ViewData["mypartialdata"] as ViewDataDictionary. Then in your view
#Html.Partial("_ModifyProfileInfo",ViewData["mypartialdata"])
In your [HttpPost] profil function, if modelstate.isvalid is false, you return your edit view, but you need to define your pmViewModel again , other wise your partial view will not have an object to display. Try using the following and let us know what happens
[HttpPost]
[Authorize]
[ValidateAntiForgeryToken]
public ActionResult Profil(ProfileModel model)
{
if (ModelState.IsValid)
{
//insert into database
return Content("everything's good");
}
else
{
//outputs form errors
var pmViewModel = new ProfileUserViewModel
{
ProfileModelObject = profileModel,
UserModelObject = userModel
};
return View(model);
}
}
While I know this question has been asked longtime ago however some people might still face a similar problem. One easy solution I use to pass or have more than one view model on a page is to use a ViewBag to hold the second object and refer to it in the view. See example bellow.
In your controller do this:
Obj2 personalDets = new Obj2();
DbContext ctx = new DbContext();
var details = ctx.GetPersonalInformation;
foreach(var item in details) {
personalDets.Password = item.Password;
personalDets .EmailAddress = item.EmailAddress;
}
ViewBag.PersonalInformation = personalDets;
Then in your view those properties become readily available for you

MVC Model State Validation fails on Listbox

I have a simple model which uses a multi select listbox for a many-many EF relationship.
On my Create action, I'm getting the error
The parameter conversion from type 'System.String' to type 'MyProject.Models.Location' failed because no type converter can convert between these types.
I have 2 models, an Article and a Location:
Article.cs
namespace MyProject.Models
{
public class Article
{
public Article()
{
Locations = new List<Location>();
}
[Key]
public int ArticleID { get; set; }
[Required(ErrorMessage = "Article Title is required.")]
[MaxLength(200, ErrorMessage = "Article Title cannot be longer than 200 characters.")]
public string Title { get; set; }
public virtual ICollection<Location> Locations { get; set; }
}
Location.cs:
namespace MyProject.Models
{
public class Location
{
[Key]
public int LocationID { get; set; }
[Required(ErrorMessage = "Location Name is required.")]
[MaxLength(100, ErrorMessage = "Location Name cannot be longer than 100 characters.")]
public string Name { get; set; }
public virtual ICollection<Article> Articles { get; set; }
}
}
I have a ViewModel:
namespace MyProject.ViewModels
{
public class ArticleFormViewModel
{
public Article article { get; set; }
public virtual List<Location> Locations { get; set; }
public ArticleFormViewModel(Article _article, List<Location> _locations)
{
article = _article;
Locations = _locations;
}
}
}
create.cshtml:
#model MyProject.ViewModels.ArticleFormViewModel
<h2>Create</h2>
#using (Html.BeginForm()) {
#Html.AntiForgeryToken()
#Html.ValidationSummary(true)
<fieldset>
<legend>Article</legend>
<div class="editor-label">
#Html.LabelFor(model => model.article.Title)
</div>
<div class="editor-field">
#Html.EditorFor(model => model.article.Title)
#Html.ValidationMessageFor(model => model.article.Title)
</div>
<h3>Locations</h3>
#Html.ListBoxFor(m=>m.article.Locations,new MultiSelectList(Model.Locations,"LocationID","Name"))
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
}
Finally my controller actions:
// GET: /Article/Create
public ActionResult Create()
{
var article = new Article();
var AllLocations = from l in db.Locations
select l;
ArticleFormViewModel viewModel = new ArticleFormViewModel(article, AllLocations.ToList());
return View(viewModel);
}
//
// POST: /Article/Create
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(Article article)
{
var errors = ModelState.Values.SelectMany(v => v.Errors);
if (ModelState.IsValid)
{
var locations = Request.Form["article.Locations"];
if (locations != null)
{
var locationIDs = locations.Split(',');
foreach (var locationID in locationIDs)
{
int id = int.Parse(locationID);
Location location = db.Locations.Where(l => l.LocationID == id).First();
article.Locations.Add(location);
}
}
db.Articles.Add(article);
db.SaveChanges();
return RedirectToAction("Index");
}
var AllLocations = from l in db.Locations
select l;
ArticleFormViewModel viewModel = new ArticleFormViewModel(article, AllLocations.ToList());
return View(viewModel);
}
This all works relatively well, my Locations listbox is populated properly:
If I do not select a Location then my model is saved properly. If I select one or more locations then my Model.IsValid check fails with the exception
The parameter conversion from type 'System.String' to type 'MyProject.Models.Location' failed because no type converter can convert between these types.
However if I remove the ModelState.IsValid check then despite the error my values are all correctly saved into the database - just that I lose validation for things such as the model title.
Hope someone can help!
Unless you create a type converter, you cannot directly bind the results of your list box directly to a complex object like that. The reason lies in the fact that MVC can only deal with posted HTTP values, which in this case are an array of strings that contain the selected ID's. Those strings do not directly map to your Locations object (ie the number 1 cannot be directly converted to a Locations object with an ID of 1).
Your best bet is to have a list of location ID's in your View Model of type string or int to accept the posted values, then in your post method create the Location objects and fill them with the correct ID's.
FYI, the reason your code works is because you are bypassing the model binding and going directly to the Request.Form collection. You will notice that the bound Article object will not have any Location objects.
EDIT:
I don't even see how your code would work even without this problem. Your ArticleFormViewModel does not have a parameterless constructor, so that will fail in model binding (unless you have a custom model binder).
In any event, what you want to do is this (note, you will have to populate SelectedLocationIDs if you want them to be selected when the view is rendered):
public class ArticleFormViewModel
{
...
List<int> SelectedLocationIDs { get; set; }
...
}
Then, in your view you have:
#Html.ListBoxFor(m=>m.SelectedLocationIDs,
new MultiSelectList(Model.Locations,"LocationID","Name"))
In your Post method, instead of the code that calls Request.Form, you have something like this:
foreach(var locationID in article.SelectedLocationIDs) {
... // look up your locations and add them to the model
}

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