I think the title says it all...
I want to update a whole table with an input filled value into a selected column (selected from a dropdown list) if the value of another column is equal to a selected value (from another dropdown list). Putting all this together seem pretty hard for me...
Like this kind of Query...
var db = Database.Open("DatabaseX");
var updateCommand = "UPDATE TableX Set SelectedColumn(dropdownlistA) = (InputA) IF ColumnX = Selected Values(dropdownlistB)";
Sorry for my english
If you are having trouble getting the selected values from the dropdown on form submit, you may try this.
Create a view model with properties for the data for the dropdown and the selected option value.
public class CreateUserVm
{
public int SelectedCam { set; get; }
public List<SelectListItem> Cams { set; get; }
public int SelectedCat { set; get; }
public List<SelectListItem> Categories { set; get; }
}
And in your GET action, create an object of this, initialize the collection properties and send tot he view.
public ActionResult Create()
{
var v = new CreateUserVm
{
Categories = new List<SelectListItem>
{
new SelectListItem {Value = "1", Text = "Photo"},
new SelectListItem {Value = "2", Text = "Video"}
},
Cams = new List<SelectListItem>
{
new SelectListItem {Value = "25", Text = "DSLR"},
new SelectListItem {Value = "28", Text = "Point and Shoot"}
}
};
return View(v);
}
Now your create view should be strongly typed to this CreateUserVm class.
#model CreateUserVm
#using(Html.BeginForm())
{
#Html.DropDownListFor(g=>g.SelectedCat, Model.Categories)
#Html.DropDownListFor(g=>g.SelectedCam, Model.Cams)
<input type="submit" />
}
And in your HttpPost action method, we will use the CreateUserVm object as the parameter so that the posted model will be mapped to it by the default model binder.
[HttpPost]
public ActionResult Create(CreateUserVm model)
{
var camId = model.SelectedCam;
var catId = model.SelectedCat;
// use camId and catId to update your db.
// to do : Save and Redirect
}
I am trying to insert to database from view page which has dropdownlist , textbox's .. when i enter something and click on save means i am getting nothing from dropdown selection which is binded .
My code :
#model IEnumerable<iWiseapp.Models.LObmodel>
#using (#Html.BeginForm("stop", "Home", FormMethod.Post))
{
#Html.DropDownList("Data",ViewBag.Data as SelectList,"select a sdsd",new {id="LOB_ID"})
#Html.DropDownListFor("sss",new SelectList(Model,"lob_id","lob_name"))
,
#Html.DropDownList("LObmodel", new SelectList(ViewBag.data ,"Value","Text"))
#Html.DropDownListFor(model => model.lob_name, new SelectList(ViewBag.Titles,"Value","Text"))
I tried above all possibilities but nah i am confused nothing working out
ADDED MY CONTROLER CODE
[HttpGet]
public ActionResult stop()
{
ServiceReference1.Service1Client ser_obj = new ServiceReference1.Service1Client();
IEnumerable<LobList> obj = ser_obj.GetData(); //i am Getting list of data through WCF from BUSINESS LAYER WHERE i created entities via EF
List<SelectListItem> ls = new List<SelectListItem>();
foreach (var temp in obj)
{
ls.Add(new SelectListItem() { Text = temp.LOB_NAME, Value = temp.LOB_ID.ToString() });
}
//then create a view model on your controller and pass this value to it
ViewModel vm = new ViewModel();
vm.DropDown = ls; // where vm.DropDown = List<SelectListItem>();
THE COMMENTED CODE BELOW IS WHAT I AM DOING
//var mode_obj = new List<LObmodel>();
//Created LOBmodel class in model which is excat same of entities in Business class
//var jobList = new List<SelectListItem>();
//foreach (var job in obj)
//{
// var item = new SelectListItem();
// item.Value = job.LOB_ID.ToString(); //the property you want to display i.e. Title
// item.Text = job.LOB_NAME;
// jobList.Add(item);
//}
//ViewBag.Data = jobList;
return View(jobList); or return view (obj)
}
Any expert advice is appreciated
MY FIELDS , IS THESE PERFECT
public class template
{
public List<LobList> LOBs { get; set; } //LOBLIST FROM Entities in business layer
public int selectedLobId { get; set; }
public LobList SelectedLob
{
get { return LOBs.Single(u=>u.LOB_ID == selectedLobId) ;}
}
}
AND
public class LObmodel
{
public int LOB_ID { get; set; }
public string LOB_NAME { get; set; }
}
I would recommend putting the selectlist into your model instead of passing it through the view bag. The option you want is
#Html.DropDownListFor(model => model.lob_name, new SelectList(ViewBag.Titles,"Value","Text"))
you can set the selected item by setting model.lob_name on the controller and on post back that value will be set to the selected value of the dropdown
on your controller you can build the list like this
List<SelectListItem> ls = new List<SelectListItem>();
foreach(var temp in model){ //where model is your database
ls.Add(new SelectListItem() { Text = temp.Text, Value = temp.Value });
}
//then create a view model on your controller and pass this value to it
LObmodel vm = new LObmodel();
vm.DropDown = ls; // where vm.DropDown = List<SelectListItem>();
return View(vm);
then on your view you can reference that
#Html.DropDownListFor(x => x.lob_name, Model.DropDown)
with your model add the select list
public class LObmodel
{
public int LOB_ID { get; set; }
public string LOB_NAME { get; set; }
public List<SelectListItem> DropDown { get; set; }
}
then the top of your view would be
#model LObmodel
I had the same problem .
But i changed the view code of DDL using this code :
#Html.DropDownListFor(x => x.ClassID, (SelectList)ViewBag.ClassName);
The dropdownlist will bind to your model class called ClassID You will not be able to post the textual value of the ddl to the controller, only the ID behind the ddl.
I have tried this is RC1 and then upgraded to RC2 which did not resolve the issue.
// in my controller
ViewData["UserId"] = new SelectList(
users,
"UserId",
"DisplayName",
selectedUserId.Value); // this has a value
result: the SelectedValue property is set on the object
// in my view
<%=Html.DropDownList("UserId", (SelectList)ViewData["UserId"])%>
result: all expected options are rendered to the client, but the selected attribute is not set. The item in SelectedValue exists within the list, but the first item in the list is always defaulted to selected.
How should I be doing this?
Update
Thanks to John Feminella's reply I found out what the issue is. "UserId" is a property in the Model my View is strongly typed to. When Html.DropDownList("UserId" is changed to any other name but "UserId", the selected value is rendered correctly.
This results in the value not being bound to the model though.
This is how I fixed this problem:
I had the following:
Controller:
ViewData["DealerTypes"] = Helper.SetSelectedValue(listOfValues, selectedValue) ;
View
<%=Html.DropDownList("DealerTypes", ViewData["DealerTypes"] as SelectList)%>
Changed by the following:
View
<%=Html.DropDownList("DealerTypesDD", ViewData["DealerTypes"] as SelectList)%>
It appears that the DropDown must not have the same name has the ViewData name :S weird but it worked.
Try this:
public class Person {
public int Id { get; set; }
public string Name { get; set; }
}
And then:
var list = new[] {
new Person { Id = 1, Name = "Name1" },
new Person { Id = 2, Name = "Name2" },
new Person { Id = 3, Name = "Name3" }
};
var selectList = new SelectList(list, "Id", "Name", 2);
ViewData["People"] = selectList;
Html.DropDownList("PeopleClass", (SelectList)ViewData["People"])
With MVC RC2, I get:
<select id="PeopleClass" name="PeopleClass">
<option value="1">Name1</option>
<option selected="selected" value="2">Name2</option>
<option value="3">Name3</option>
</select>
You can still name the DropDown as "UserId" and still have model binding working correctly for you.
The only requirement for this to work is that the ViewData key that contains the SelectList does not have the same name as the Model property that you want to bind. In your specific case this would be:
// in my controller
ViewData["Users"] = new SelectList(
users,
"UserId",
"DisplayName",
selectedUserId.Value); // this has a value
// in my view
<%=Html.DropDownList("UserId", (SelectList)ViewData["Users"])%>
This will produce a select element that is named UserId, which has the same name as the UserId property in your model and therefore the model binder will set it with the value selected in the html's select element generated by the Html.DropDownList helper.
I'm not sure why that particular Html.DropDownList constructor won't select the value specified in the SelectList when you put the select list in the ViewData with a key equal to the property name. I suspect it has something to do with how the DropDownList helper is used in other scenarios, where the convention is that you do have a SelectList in the ViewData with the same name as the property in your model. This will work correctly:
// in my controller
ViewData["UserId"] = new SelectList(
users,
"UserId",
"DisplayName",
selectedUserId.Value); // this has a value
// in my view
<%=Html.DropDownList("UserId")%>
The code in the previous MVC 3 post does not work but it is a good start. I will fix it. I have tested this code and it works in MVC 3 Razor C# This code uses the ViewModel pattern to populate a property that returns a List<SelectListItem>.
The Model class
public class Product
{
public string Name { get; set; }
public decimal Price { get; set; }
}
The ViewModel class
using System.Web.Mvc;
public class ProductListviewModel
{
public List<SelectListItem> Products { get; set; }
}
The Controller Method
public ViewResult List()
{
var productList = new List<SelectListItem>();
foreach (Product p in Products)
{
productList.Add(new SelectListItem
{
Value = p.ProductId.ToString(),
Text = "Product: " + p.Name + " " + p.Price.ToString(),
// To set the selected item use the following code
// Note: you should not set every item to selected
Selected = true
});
}
ProductListViewModel productListVM = new ProductListViewModeld();
productListVM.Products = productList;
return View(productListVM);
}
The view
#model MvcApp.ViewModels.ProductListViewModel
#using (Html.BeginForm())
{
#Html.DropDownList("Products", Model.Products)
}
The HTML output will be something like
<select id="Products" name="Products">
<option value="3">Product: Widget 10.00</option>
<option value="4">Product: Gadget 5.95</option>
</select>
depending on how you format the output. I hope this helps. The code does work.
If we don't think this is a bug the team should fix, at lease MSDN should improve the document. The confusing really comes from the poor document of this. In MSDN, it explains the parameters name as,
Type: System.String
The name of the form field to return.
This just means the final html it generates will use that parameter as the name of the select input. But, it actually means more than that.
I guess the designer assumes that user will use a view model to display the dropdownlist, also will use post back to the same view model. But in a lot cases, we don't really follow that assumption.
Use the example above,
public class Person {
public int Id { get; set; }
public string Name { get; set; }
}
If we follow the assumption,we should define a view model for this dropdownlist related view
public class PersonsSelectViewModel{
public string SelectedPersonId,
public List<SelectListItem> Persons;
}
Because when post back, only the selected value will post back, so it assume it should post back to the model's property SelectedPersonId, which means Html.DropDownList's first parameter name should be 'SelectedPersonId'. So, the designer thinks that when display the model view in the view, the model's property SelectedPersonId should hold the default value of that dropdown list. Even thought your List<SelectListItem> Persons already set the Selected flag to indicate which one is selected/default, the tml.DropDownList will actually ignore that and rebuild it's own IEnumerable<SelectListItem> and set the default/selected item based on the name.
Here is the code from asp.net mvc
private static MvcHtmlString SelectInternal(this HtmlHelper htmlHelper, ModelMetadata metadata,
string optionLabel, string name, IEnumerable<SelectListItem> selectList, bool allowMultiple,
IDictionary<string, object> htmlAttributes)
{
...
bool usedViewData = false;
// If we got a null selectList, try to use ViewData to get the list of items.
if (selectList == null)
{
selectList = htmlHelper.GetSelectData(name);
usedViewData = true;
}
object defaultValue = (allowMultiple) ? htmlHelper.GetModelStateValue(fullName, typeof(string[])) : htmlHelper.GetModelStateValue(fullName, typeof(string));
// If we haven't already used ViewData to get the entire list of items then we need to
// use the ViewData-supplied value before using the parameter-supplied value.
if (defaultValue == null && !String.IsNullOrEmpty(name))
{
if (!usedViewData)
{
defaultValue = htmlHelper.ViewData.Eval(name);
}
else if (metadata != null)
{
defaultValue = metadata.Model;
}
}
if (defaultValue != null)
{
selectList = GetSelectListWithDefaultValue(selectList, defaultValue, allowMultiple);
}
...
return tagBuilder.ToMvcHtmlString(TagRenderMode.Normal);
}
So, the code actually went further, it not only try to look up the name in the model, but also in the viewdata, as soon as it finds one, it will rebuild the selectList and ignore your original Selected.
The problem is, in a lot of cases, we don't really use it that way. we just want to throw in a selectList with one/multiple item(s) Selected set true.
Of course the solution is simple, use a name that not in the model nor in the viewdata. When it can not find a match, it will use the original selectList and the original Selected will take affect.
But i still think mvc should improve it by add one more condition
if ((defaultValue != null) && (!selectList.Any(i=>i.Selected)))
{
selectList = GetSelectListWithDefaultValue(selectList, defaultValue, allowMultiple);
}
Because, if the original selectList has already had one Selected, why would you ignore that?
Just my thoughts.
This appears to be a bug in the SelectExtensions class as it will only check the ViewData rather than the model for the selected item. So the trick is to copy the selected item from the model into the ViewData collection under the name of the property.
This is taken from the answer I gave on the MVC forums, I also have a more complete answer in a blog post that uses Kazi's DropDownList attribute...
Given a model
public class ArticleType
{
public Guid Id { get; set; }
public string Description { get; set; }
}
public class Article
{
public Guid Id { get; set; }
public string Name { get; set; }
public ArticleType { get; set; }
}
and a basic view model of
public class ArticleModel
{
public Guid Id { get; set; }
public string Name { get; set; }
[UIHint("DropDownList")]
public Guid ArticleType { get; set; }
}
Then we write a DropDownList editor template as follows..
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %>
<script runat="server">
IEnumerable<SelectListItem> GetSelectList()
{
var metaData = ViewData.ModelMetadata;
if (metaData == null)
{
return null;
}
var selected = Model is SelectListItem ? ((SelectListItem) Model).Value : Model.ToString();
ViewData[metaData.PropertyName] = selected;
var key = metaData.PropertyName + "List";
return (IEnumerable<SelectListItem>)ViewData[key];
}
</script>
<%= Html.DropDownList(null, GetSelectList()) %>
This will also work if you change ArticleType in the view model to a SelectListItem, though you do have to implement a type converter as per Kazi's blog and register it to force the binder to treat this as a simple type.
In your controller we then have...
public ArticleController
{
...
public ActionResult Edit(int id)
{
var entity = repository.FindOne<Article>(id);
var model = builder.Convert<ArticleModel>(entity);
var types = repository.FindAll<ArticleTypes>();
ViewData["ArticleTypeList"] = builder.Convert<SelectListItem>(types);
return VIew(model);
}
...
}
The problems is that dropboxes don't work the same as listboxes, at least the way ASP.NET MVC2 design expects: A dropbox allows only zero or one values, as listboxes can have a multiple value selection. So, being strict with HTML, that value shouldn't be in the option list as "selected" flag, but in the input itself.
See the following example:
<select id="combo" name="combo" value="id2">
<option value="id1">This is option 1</option>
<option value="id2" selected="selected">This is option 2</option>
<option value="id3">This is option 3</option>
</select>
<select id="listbox" name="listbox" multiple>
<option value="id1">This is option 1</option>
<option value="id2" selected="selected">This is option 2</option>
<option value="id3">This is option 3</option>
</select>
The combo has the option selected, but also has its value attribute set. So, if you want ASP.NET MVC2 to render a dropbox and also have a specific value selected (i.e., default values, etc.), you should give it a value in the rendering, like this:
// in my view
<%=Html.DropDownList("UserId", selectListItems /* (SelectList)ViewData["UserId"]*/, new { #Value = selectedUser.Id } /* Your selected value as an additional HTML attribute */)%>
In ASP.NET MVC 3 you can simply add your list to ViewData...
var options = new List<SelectListItem>();
options.Add(new SelectListItem { Value = "1", Text = "1" });
options.Add(new SelectListItem { Value = "2", Text = "2" });
options.Add(new SelectListItem { Value = "3", Text = "3", Selected = true });
ViewData["options"] = options;
...and then reference it by name in your razor view...
#Html.DropDownList("options")
You don't have to manually "use" the list in the DropDownList call. Doing it this way correctly set the selected value for me too.
Disclaimer:
Haven't tried this with the web forms view engine, but it should work too.
I haven't tested this in the v1 and v2, but it might work.
I managed to get the desired result, but with a slightly different approach. In the Dropdownlist i used the Model and then referenced it. Not sure if this was what you were looking for.
#Html.DropDownList("Example", new SelectList(Model.FeeStructures, "Id", "NameOfFeeStructure", Model.Matters.FeeStructures))
Model.Matters.FeeStructures in above is my id, which could be your value of the item that should be selected.
am unable to get correct value from drop down in mvc4. my edit view code is
#Html.DropDownList("IDCountry", (IEnumerable<SelectListItem>)ViewBag.IDCountry,
new { #class = "span6" })
if i use below code am able to get correct value but am unable to apply style for dropdownlist
#Html.DropDownList("IDCountry",String.empty)
please solve my problem.
You should not use the same value (IDCountry) as first and second argument for the dropdown. The first argument represents the value to bind the dropdown to while the second represents the available values. So:
#Html.DropDownList(
"SelectedCountryID",
(IEnumerable)ViewBag.IDCountry,
new { #class = "span6" }
)
To avoid all those confusions with Dropdowns I would recommend you using a view model:
public class MyViewModel
{
public string SelectedCountryID { get; set; }
public IEnumerable<SelectListItem> Countries { get; set; }
}
and then your controller action will populate and pass this view model to the view:
public class HomeController: Controller
{
public ActionResult Index()
{
var model = new MyViewModel();
// preselected an element with Value = "2"
model.SelectedCountryID = "2";
// obviously those values could come from a database or something
model.Countries = new[]
{
new SelectListItem { Value = "1", Text = "Country 1" },
new SelectListItem { Value = "2", Text = "Country 2" },
new SelectListItem { Value = "3", Text = "Country 3" },
new SelectListItem { Value = "4", Text = "Country 4" },
};
return View(model);
}
[HttpPost]
public ActionResult Index(MyViewModel model)
{
return Content("Thanks for selecting country ID: " + model.SelectedCountryID);
}
}
and finally in your view use the strongly typed helper:
#model MyViewModel
#using (Html.BeginForm())
{
<div>
#Html.LabelFor(x => x.SelectedCountryID)
#Html.DropDownListFor(
x => x.SelectedCountryID,
Model.Countries,
new { #class = "span6" }
)
</div>
<button type="submit">OK</button>
}
See how the very instant you STOP using ViewBag and remove absolutely all traces from it in your application everything becomes crystal clear?
I have run into an issue that seems pretty simple, but I have not been able to find a solution. I have created a ReportModel object that is the model in the view. The ReportModel contains a list of FinancialHistory objects. I populate the objects and display them in a table of textboxes within a form in the view using default binding (This works correctly). The user can then submit the form to refresh the FinancialHistory objects from a different datasource, replacing what was previously in the list with the new results. When the new results are returned, I can see that the model contains the expected new values, but when the HTML is rendered, the original amounts still appear. If the new results contains more objects than the original list (as shown in the example code), the added rows do appear with the correct values. So, if the original had 2 objects and the refreshed list has 3, the resulting HTML shows the first 2 rows with the old values and a 3rd row with the new values.
Here are the models:
public class ReportModel
{
public string AccountNumber { get; set; }
public IList<FinancialHistory> FinancialHistories { get; set; }
}
public class FinancialHistory
{
public FinancialHistory()
{
Id = Guid.Empty;
}
public Guid Id { get; set; }
public DateTime TransactionDate { get; set; }
public decimal TotalAmount { get; set; }
}
In the Home/Index view, I use HTML.TextBoxFor() to bind the properties of each FianancialHistory object in the list to textboxes in a table. Here is the Index view:
#model SimpleExample.Models.ReportModel
<form id="FormSave" method="post" name="FormSave" action="/Home/Refresh">
#Html.LabelFor(model => model.AccountNumber) #Html.TextBoxFor(model => model.AccountNumber)
<table class="table" style="width: 95%">
<tr>
<td >Date</td>
<td >Amount</td>
</tr>
#{
if (Model.FinancialHistories != null)
{
for (int index = 0; index <= Model.FinancialHistories.Count - 1; index++)
{
<tr>
<td>#Html.TextBoxFor(model => model.FinancialHistories [index].TransactionDate, "{0:MM/dd/yyyy}", new { #readonly = "true" })</td>
<td>#Html.TextBoxFor(model => model.FinancialHistories[index].TotalAmount, "{0:#,#.00}", new { #readonly = "true" })</td>
<td>#Html.HiddenFor(model => model.FinancialHistories[index].Id)</td>
</tr>
}
}
}
</table>
<input type="submit" id="submit" value="Refresh" class="submit" />
</form>
For this example, my action methods in the controller are very simple. Initially, the Index method populates the list with 2 FinancialHistory Objects. The Refresh method replaces the original 2 objects with 3 new objects, with different amounts.
public class HomeController : Controller
{
public ActionResult Index()
{
ReportModel reportModel = new ReportModel();
reportModel.AccountNumber = "123456789";
IList<FinancialHistory> financialHistories = new List<FinancialHistory>();
financialHistories.Add(new FinancialHistory
{
Id = Guid.NewGuid(),
TransactionDate = DateTime.Parse("3/1/2010"),
TotalAmount = 1000.00M
});
financialHistories.Add(new FinancialHistory
{
Id = Guid.NewGuid(),
TransactionDate = DateTime.Parse("4/1/2011"),
TotalAmount = 2000.00M
});
reportModel.FinancialHistories = financialHistories;
return View(reportModel);
}
public ActionResult Refresh(ReportModel reportModel)
{
FinancialHistoryRepository financialHistoryRepository = new FinancialHistoryRepository();
IList<FinancialHistory> financialHistories = new List<FinancialHistory>();
financialHistories.Add(new FinancialHistory
{
Id = Guid.Empty,
TransactionDate = DateTime.Parse("3/1/2010"),
TotalAmount = 1111.11M
});
financialHistories.Add(new FinancialHistory
{
Id = Guid.Empty,
TransactionDate = DateTime.Parse("4/1/2011"),
TotalAmount = 2222.22M
});
financialHistories.Add(new FinancialHistory
{
Id = Guid.Empty,
TransactionDate = DateTime.Parse("5/1/2012"),
TotalAmount = 3333.33M
});
reportModel.FinancialHistories = financialHistories;
return View("Index",reportModel);
}
}
That's how HTML helpers work and is by design. When rendering they are first looking in the ModelState for values and after that in the model. You are modifying the values of your model in the POST controller action, but the ModelState values still contain the old values which will be used. If you want to modify values of your model in a POST action you should remove the original values from the ModelState if you intend to redisplay the same view:
public ActionResult Refresh(ReportModel reportModel)
{
// clear the original posted values so that they don't get picked up
// by the helpers
ModelState.Clear();
FinancialHistoryRepository financialHistoryRepository = new FinancialHistoryRepository();
...
return View("Index",reportModel);
}