I have a problem with DropDownlist in MVC
I use ModelView in my application and this is my code
namespace MedicallexiconProject.ViewModel
{
public class WordViewModel
{
private readonly ICategoryService _categoryService;
public WordViewModel(ICategoryService categoryService)
{
_categoryService = categoryService;
var selectList = _categoryService.GetAllCategorysSelectList().
Select(x => new SelectListItem
{
Text = x.Name,
Value = x.ID.ToString()
}).ToList();
Categories = selectList;
}
public WordViewModel()
{
}
public string Name { get; set; }
private IList<SelectListItem> _categories;
public IList<SelectListItem> Categories
{
get
{
if (_categories == null)
{
_categories = new List<SelectListItem>();
}
return (_categories);
}
set { _categories = value; }
}
}
}
and this is my controller
[HttpGet]
public ActionResult Create()
{
var wordViewModel = new WordViewModel(_categoryService);
ViewBag.CategoryID = wordViewModel.Categories;
return View();
}
[HttpPost]
public ActionResult Create(WordViewModel wordViewModel)
{
Mapper.CreateMap<WordViewModel, Word>();
var word = new Word();
Mapper.Map(wordViewModel, word);
if (ModelState.IsValid)
{
_wordService.AddNewWord(word);
_uow.SaveChanges();
return RedirectToAction("Index");
}
return View(wordViewModel);
}
Now how can I insert dropdownlist in my View?
As AlfalfaStrange mentioned, you should not add logic in your ViewModel. That makes it ugly ! Keep your ViewModel simple POCO.
Add one more property in your ViewModel called "SelectedCategoryID" like this
public class WordViewModel
{
public int SelectedCategoryID { set;get;}
public IList<SelectListItem> Categories { set;get;}
public string Name { set;get;}
}
Initialize your Items (Categories) of your ViewModel in your GET method. Here i am calling a method called GetCategories which returns a list of categories.I can simply call the method wherever i want.
public ActionResult Create()
{
var model=new WordViewModel();
model.Categories=YourService.GetCategories();
return View(model);
}
In your strongly typed Create view , use this
#model WordViewModel
using(#Html.BeginForm())
{
#Html.DropDownFor(x=>x.SelectedCategoryID,
new SelectList(Model.Categories,"Value","Text"),"Select Category")
<input type="submit" value="Save" />
}
In your HttpPost action method , you can check for wordViewModel.SelectedCategoryID for the selected value.
[HttpPost]
public ActionResult Create(WordViewModel wordViewModel)
{
if(ModelState.IsValid)
{
//Checck for wordViewModel.SelectedCategoryID here now
}
//some validation failed. Let's reload the category data again.
wordViewModel.Categories=YourService.GetCategories();
return View(wordViewModel);
}
It's absolutely fine to include code that loads a dropdown list in your view model. A select list and a drop down are both "view" items.... they are not related to business logic and your controller and model need not know anything about SelectLists or SelectListItems or DropDownList, etc.
Related
Selected value is not coming when I am trying to check, drop down list is showing all the names, but when I am trying to show the selected value of the dropdownlist in the controller, option is not coming.
Controller:
public ActionResult Index1()
{
Class1 cs1 = new Class1();
return View(cs1);
}
[HttpPost]
public ActionResult Index1(Class1 cs)
{
var selecteditem = cs.psudetail.Find(p => p.Section_PSU == cs.psudetail.ToString());
if (selecteditem != null)
{
}
}
Model class:
namespace WebApplication1.Models
{
public class Class1
{
public List<PSUMaster> psudetail
{
get
{
PSUEntities pe = new PSUEntities();
return pe.PSUMasters.ToList();
}
}
}
}
And the View with Model:
#model WebApplication1.Models.Class1
#{
ViewBag.Title = "Index1";
}
<br />
#Html.DropDownListFor(m => m.psudetail, new SelectList(Model.psudetail, "S_no", "Section_PSU"), "--Select PSU--")
You need to have a property that can "store" the selection you make in the list. Extend the view model (Class1) to include a property SelectedPSU. I guess that S_no in the PSUMaster is the ID, and of type integer. Otherwise adjust the code accordingly!
I have also changed the list to be just a list, and then the controller can worry about populating it. This pattern fits MVC better (keep the model simple).
Updated class:
namespace WebApplication1.Models
{
public class PsuViewModel
{
public int SelectedPSU { get; set; }
public List<PSUMaster> PSU { get; set; }
}
}
Next, the controller has to be updated to pass the list to the view model in the GET Index method:
public ActionResult Index1()
{
var pe = new PSUEntities();
return View(new PsuViewModel {
PSU = pe.PSUMasters.ToList()
});
}
Now we can use the SelectedPSU property in our view:
#model WebApplication1.Models.Class1
#{
ViewBag.Title = "Index1";
}
<br />
#Html.DropDownListFor(m => m.SelectedPSU, new SelectList(Model.PSU, "S_no", "Section_PSU"), "--Select PSU--")
...and we can get the ID in the controller:
[HttpPost]
public ActionResult Index1(PsuViewModel model)
{
var pe = new PSUEntities();
var selectedPsu = pe.PSUMasters.FirstOrDefault(p => p.S_no == model.SelectedPSU);
if (selectedPsu != null) {
// ...
}
}
This is my model
public class MessageSetTypeCollection<T> : CollectionBase where T : MessageSetType, new()
{
public string Name { get; set; }
public string[] Tags { get; set; }
public MessageSetType this[int index]
{
get
{
return (MessageSetType)List[index];
}
}
public void Add(MessageSetType value)
{
List.Add(value);
}
}
This is my controller actions
public ActionResult TestAction()
{
MessageSetTypeCollection<MessageSetType> Model = new MessageSetTypeCollection<MessageSetType>();
Model.Add(new MessageSetType()
{
Alert = "test" // Alert is a public property of the MessageSetType class
});
Model.Add(new MessageSetType()
{
Alert = "test2"
});
return View(Model);
}
[HttpPost]
public void TestAction(MessageSetTypeCollection<MessageSetType> Model)
{
return;
}
In the view I've this code
#using (Html.BeginForm())
{
#Html.EditorFor(a => a[0].Alert)
#Html.EditorFor(a => a[1].Alert)
<input type="submit" value="OK" />
}
When I submit this form to the TestAction action, the inner list into the Model parameter has a Count of 0 elements. Why?
I've also tested this code with List<MessageSetType> model type instead of MessageSetTypeCollection<MessageSetType> and all works correctly. Where is the error?
Please see here source code for List:
http://referencesource.microsoft.com/#mscorlib/system/collections/generic/list.cs
The implementation is pretty different. You don't have a collection of type MessageSetType on which your indexer should work.
I think you can use source code of to adjust your model: MessageSetTypeCollection.
I've resolved inheriting the MessageSetTypeCollection<T> from List<T> instead of CollectionBase
public class MessageSetTypeCollection<T> : List<T> where T : MessageSetType, new()
{
//Omissis
}
I have two dropdown lists and two textboxes
Search By: ByHtml.DropDownList("Search1", "Please Select...")
Html.TextBox("searchString1")
Search By: Html.DropDownList("Search2", "Please Select...")
#Html.TextBox("searchString2")
<input type="submit" value="Filter" />
When I make my selection from whichever DDL and type text into the textbox and hit filter my search returns, however after the search the text remains in the textbox, is there a way of clearing it after the search so that the textbox is empty again? I tried
ModelState.Remove("");
but it didn't work.
A sample from My controller code is
public class MainController : Controller
{
private DBEntities db = new DBEntities();
// GET: /Main/
public ActionResult Index(string searchString1, string searchString2, string Search1, string Search2)
{
//Create a Dropdown list
var SearchOptionList = new List<string>();
SearchOptionList.Add("LandLord");
SearchOptionList.Add("Postcode");
SearchOptionList.Add("Street Address");
ViewBag.Search1 = new SelectList(SearchOptionList);
ViewBag.Search2 = new SelectList(SearchOptionList);
var mylist = from m in "mydatabase" select m;
//This statement runs if the user selects a parameter from Search2 and leaves Search1 empty
if (String.IsNullOrEmpty(Search1) && !String.IsNullOrEmpty(Search2))
{
if (Search2 == "Postcode")
{
mylist = mylist.Where(s => s.Postcode.Contains(searchString2));
}
if (Search2 == "LandLord")
{
mylist = mylist.Where(s => s.Name.Contains(searchString2));
}
if (Search2 == "Street Address")
{
mylist = mylist.Where(s => s.StreetAddress.Contains(searchString2));
}
}
return View(mylist.ToList());
}
Your should have a view model containing properties searchString1 and searchString2 and the select lists
public class SearchVM
{
public string searchString1 { get; set; }
public string searchString2 { get; set; }
public SelectList SearchList1 { get; set; }
public SelectList SearchList2 { get; set; }
}
Controller
public ActionResult Search()
{
SearchVM model = new SearchVM();
model.SearchList1 = new SelctList(...);
model.SearchList2 = new SelctList(...);
return View(model);
}
View
#model SearchVM
#using(Html.BeginForm())
{
....
#Html.DropDownListFor(m => m.searchString1, Model.SearchList1, "--Please select--")
#Html.DropDownListFor(m => m.searchString2, Model.SearchList2, "--Please select--")
....
}
Post
[HttpPost]
public ActionResult Search(SearchVM model)
{
// to clear all modelstate and reset values
ModelState.Clear();
model.searchString1 = null;
model.searchString2 = null;
// or to clear just one property and reset it
ModelState.Remove("searchString1");
model.searchString1 = null;
// repopulate select lists if your returning the view
return View(model);
}
At the end of my public ActionResult Index method but before return View() I placed the following code which worked perfectly
ModelState.Remove("searchString1");
ModelState.Remove("searchString2");
ModelState.Remove("Search1");
ModelState.Remove("Search2");
I know is an old question, but I fall in the same issue. So I put my solution.
View:
#Html.TextBox("Search", null, new { #autofocus = "autofocus" })
Controller:
ViewBag.Search= null;
ModelState.Remove("Search");
return View(list.ToList());
Hope to help someone
I am trying to move from webForms to Asp.net-MVC and have some problems. I am trying to figure why this is not working, I am getting this error: "Object reference not set to an instance of an object"
I have the class 'Pages':
namespace _2send.Model
{
public class Pages
{
public string PageContent { get; set; }
public string PageName { get; set; }
public int LanguageId { get; set; }
}
}
I am inserting the value to 'Pages.PageContent' property with this class:
namespace _2send.Model.Services
{
public class PagesService : IPagesService
{
public void GetFooterlinksPage()
{
DB_utilities db_util = new DB_utilities();
SqlDataReader dr;
Pages pages = new Pages();
using (dr = db_util.procSelect("[Pages_GetPageData]"))
{
if (dr.HasRows)
{
dr.Read();
pages.PageContent = (string)dr["PageContent"];
dr.Close();
}
}
}
The Controller method looks like this:
private IPagesService _pagesService;
public FooterLinksPageController(IPagesService pagesService)
{
_pagesService = pagesService;
}
public ActionResult GetFooterLinksPage()
{
_pagesService.GetFooterlinksPage();
return View();
}
I am trying to write the property in the view like this:
#model _2send.Model.Pages
<div>
#Model.PageContent;
</div>
When debugging, the method is fired and the dataReader is inserting the value to the 'PageContent' property, but I am still getting this error from the view.
Thanks!
return View();
You didn't pass a model.
You need to pass the model as a parameter to the View() method.
You need to rewrite service method to return Pages:
public Pages GetFooterlinksPage()
{
DB_utilities db_util = new DB_utilities();
Pages pages = new Pages();
using (var dr = db_util.procSelect("[Pages_GetPageData]"))
{
if (dr.HasRows)
{
dr.Read();
pages.PageContent = (string)dr["PageContent"];
return pages;
// Because you use using, you don't need to close datareader
}
}
}
And then rewrite your action method:
public ActionResult GetFooterLinksPage()
{
var viewmodel = _pagesService.GetFooterlinksPage();
return View(viewmodel);
}
You can return a model:
var viewmodel = new _2send.Model.Pages().
//here you configure your properties
return View(viewmodel);
I want to display a string type as checkbox on MVC view, but returns it as string type on HTTP post. The problem is that it returns false on HTTP Post. Below is my code:
View:
#model List<Car>
foreach(var car in Model){
bool isFourWheel = false;
if(bool.TryParse(car.IsFourWheel, out isFourWheel){
#Html.CheckBox("IsFourWheel", isFourWheel); //need to be rendered as checkbox, but returns string type on HTTP POST
}
}
Model:
public class Car
{
public string IsFourWheel { get; set; } //bad naming, but it can contain any type, include boolean
}
Controller:
public ActionResult Index()
{
var cars = new List<Car>(){ new Car(){IsFourWheel = "true"},new Car(){IsFourWheel = "false"} };
return View(cars);
}
[HttpPost]
public ActionResult Index(List<Car> cars) **Problem IsFourWheel is false when true is selected **
{
return View(cars);
}
Any ideal would be very much appreciated.
You can try specifying a template name in your helper:
#Html.EditorFor(car => car.IsFourWheel, "CheckBox")
And defining the template to render the data the way you want, in either ~/Views/{YourControllerName}/EditorTemplates/CheckBox.cshtml or ~/Views/Shared/EditorTemplates/CheckBox.cshtml.
You can find a whole series of post by Brad Wilson on MVC templates here:
Brad Wilson: ASP.NET MVC 2 Templates, Part 1: Introduction
It is for MVC 2, but most concepts still apply to MVC 3 as well (save for the Razor syntax).
Update:
Actually you probably don't need a custom template for this. Try using #Html.CheckBoxFor(car => car.IsFourWheel) instead.
Update 2:
Drop the following template in ~/Views/Shared/EditorTemplates:
IsFourWheel.cshtml
#functions {
private bool IsChecked() {
if (ViewData.Model == null) return false;
return Convert.ToBoolean(ViewData.Model, System.Globalization.CultureInfo.InvariantCulture);
}
}
#Html.CheckBox("", IsChecked(), new { #class = "check-box" })
Then from your view, call it like so:
#Html.EditorFor(model => model.IsFourWheel, "IsFourWheel")
I tested it and binding works in both GET and POST scenarios.
You could alter your viewmodel like this:
public class Car
{
public string IsFourWheel { get; set; }
public bool IsFourWheelBool { get { return bool.Parse(IsFourWheel); } }
}
Your view would look like this:
#Html.EditFor(x => x.IsFourWheelBool);
I think it will be easier, if you add an Id to your model. Just like this
Model:
public class Car
{
public int CarID { get; set; }
public string IsFourWheel { get; set; }
}
View:
#model IEnumerable<Car>
foreach (var car in Model)
{
if(car.IsFourWheel == "true"){
<input type="checkbox" name="carID" value="#car.CarID" checked="checked" />
}
else
{
<input type="checkbox" name="carID" value="#car.CarID" />
}
}
Controller:
[HttpPost]
public ActionResult Index(List<int> carID)
{
//handle selected cars here
return View();
}