I'm using the DropDownListFor helper method inside of an edit page and I'm not having any luck getting it to select the value that I specify. I noticed a similar question on Stackoverflow. The suggested workaround was to, "populate your SelectList in the view code". The problem is that I've already tried this and it's still not working.
<%= Html.DropDownListFor(model => model.States, new SelectList(Model.States.OrderBy(s => s.StateAbbr), "StateAbbr", "StateName", Model.AddressStateAbbr), "-- Select State --")%>
I have set a breakpoint and have verified the existence (and validity) of model.AddressStateAbbr. I'm just not sure what I'm missing.
After researching for an hour, I found the problem that is causing the selected to not get set to DropDownListFor. The reason is you are using ViewBag's name the same as the model's property.
Example
public class employee_insignia
{
public int id{get;set;}
public string name{get;set;}
public int insignia{get;set;}//This property will store insignia id
}
// If your ViewBag's name same as your property name
ViewBag.Insignia = new SelectList(db.MtInsignia.AsEnumerable(), "id", "description", 1);
View
#Html.DropDownListFor(model => model.insignia, (SelectList)ViewBag.Insignia, "Please select value")
The selected option will not set to dropdownlist, BUT When you change ViewBag's name to different name the selected option will show correct.
Example
ViewBag.InsigniaList = new SelectList(db.MtInsignia.AsEnumerable(), "id", "description", 1);
View
#Html.DropDownListFor(model => model.insignia, (SelectList)ViewBag.InsigniaList , "Please select value")
If you're doing it properly and using a model--unlike all these ViewBag weirdos--and still seeing the issue, it's because #Html.DropDownListFor(m => m.MyValue, #Model.MyOptions) can't match MyValue with the choices it has in MyOptions. The two potential reasons for that are:
MyValue is null. You haven't set it in your ViewModel. Making one of MyOptions have a Selected=true won't solve this.
More subtly, the type of MyValue is different than the types in MyOptions. So like, if MyValue is (int) 1, but your MyOptions are a list of padded strings {"01", "02", "03", ...}, it's obviously not going to select anything.
Try:
<%= Html.DropDownListFor(
model => model.AddressStateAbbr,
new SelectList(
Model.States.OrderBy(s => s.StateAbbr),
"StateAbbr",
"StateName",
Model.AddressStateAbbr), "-- Select State --")%>
or in Razor syntax:
#Html.DropDownListFor(
model => model.AddressStateAbbr,
new SelectList(
Model.States.OrderBy(s => s.StateAbbr),
"StateAbbr",
"StateName",
Model.AddressStateAbbr), "-- Select State --")
The expression based helpers don't seem to respect the Selected property of the SelectListItems in your SelectList.
While not addressing this question - it may help future googlers if they followed my thought path:
I wanted a multiple select and this attribute hack on DropDownListFor wasn't auto selecting
Html.DropDownListFor(m => m.TrainingLevelSelected, Model.TrainingLevelSelectListItems, new {multiple= "multiple" })
instead I should have been using ListBoxFor which made everything work
Html.ListBoxFor(m => m.TrainingLevelSelected, Model.TrainingLevelSelectListItems)
I also having similar issue and I solve it by as follows,
set the
model.States property on your controller to what you need to be selected
model.States="California"
and then you will get "California" as default value.
I encountered this issue recently. It drove me mad for about an hour.
In my case, I wasn't using a ViewBag variable with the same name as the model property.
After tracing source control changes, the issue turned out to be that my action had an argument with the same name as the model property:
public ActionResult SomeAction(string someName)
{
var model = new SomeModel();
model.SomeNames = GetSomeList();
//Notice how the model property name matches the action name
model.someName = someName;
}
In the view:
#Html.DropDownListFor(model => model.someName, Model.SomeNames)
I simply changed the action's argument to some other name and it started working again:
public ActionResult SomeAction(string someOtherName)
{
//....
}
I suppose one could also change the model's property name but in my case, the argument name is meaningless so...
Hopefully this answer saves someone else the trouble.
I know this is an old question but I have been having the same issue in 2020.
It turns out the issue was with the model property being called "Title", I renamed it to "GivenTitle" and it now works as expected.
From
Html.DropDownListFor(m => m.Title, Model.Titles, "Please Select", new { #class = "form-control" })
to
Html.DropDownListFor(m => m.GivenTitle, Model.GivenTitles, "Please Select", new { #class = "form-control" })
this problem is common. change viewbag property name to other then model variable name used on page.
One other thing to check if it's not all your own code, is to make sure there's not a javascript function changing the value on page load. After hours of banging my head against a wall reading through all these solutions, I discovered this is what was happening with me.
The issue at least for me was tied to the IEnumerable<T>.
Basically what happened was that the view and the model did not have the same reference for the same property.
If you do this
IEnumerable<CoolName> CoolNames {get;set;} = GetData().Select(x => new CoolName{...});}
Then bind this using the
#Html.DropDownListFor(model => model.Id, Model.CoolNames)
The View loses track of the CoolNames property,
a simple fix is just to add .ToList() After dooing a projection (.Select()) ;).
I had the same problem. In the example below The variable ViewData["DATA_ACREDITO_MODELO_INTEGRADO"] has a SelectListItem list with a default selected value but such attribute is not reflected visually.
// data
var p_estadoAcreditacion = "NO";
var estadoAcreditacion = new List<SelectListItem>();
estadoAcreditacion.Add(new SelectListItem { Text = "(SELECCIONE)" , Value = " " });
estadoAcreditacion.Add(new SelectListItem { Text = "SI" , Value = "SI" });
estadoAcreditacion.Add(new SelectListItem { Text = "NO" , Value = "NO" });
if (!string.IsNullOrEmpty(p_estadoAcreditacion))
{
estadoAcreditacion.First(x => x.Value == p_estadoAcreditacion.Trim()).Selected = true;
}
ViewData["DATA_ACREDITO_MODELO_INTEGRADO"] = estadoAcreditacion;
I solved it by making the first argument of DropdownList, different to the id attribute.
// error:
#Html.DropDownList("SELECT__ACREDITO_MODELO_INTEGRADO"
, ViewData["DATA_ACREDITO_MODELO_INTEGRADO"] as List<SelectListItem>
, new
{
id = "SELECT__ACREDITO_MODELO_INTEGRADO"
...
// solved :
#Html.DropDownList("DROPDOWNLIST_ACREDITO_MODELO_INTEGRADO"
, ViewData["DATA_ACREDITO_MODELO_INTEGRADO"] as List<SelectListItem>
, new
{
id = "SELECT__ACREDITO_MODELO_INTEGRADO"
...
Related
I feel like this is very simple and I have done my research here:
Research
But it is not working.
Controller:
ViewBag.OwnerValue = new SelectList(db.tableName, "ID", "AName", object.OwnerID);
View:
#Html.DropDownListFor(model => model.AID, ViewBag.OwnerValue as SelectList, new { #class = "form-control" })
In my research the answer said to change the name of the ViewBag property so that it doesn't match the actual property name.. so that's what I did and the selected value is still not being set.
Any help is appreciated.
You would need to set the model property AID before passing the result to View in your controller action:
ViewBag.OwnerValue = new SelectList(db.tableName, "ID", "AName");
model.AID = object.OwnerID;
return View(model);
I have a DDL in my view and i read items and values of this DDL from DB like this :
ViewBag.ContentGroup = new SelectList(obj.GetContentGrouplist(), "Id", "Name");
I put it in viewbag and i read the viewbag from the view like this :
<div class="editor-label">
#Html.LabelFor(model => model.ContentGroupFKId)
</div>
<div class="editor-field">
#Html.DropDownListFor(x => x.ContentGroupFKId, (SelectList)ViewBag.ContentGroup)
#Html.ValidationMessageFor(model => model.ContentGroupFKId)
</div>
So i need a DDL that the first item of that be null how can i do that?
I tried this but it doesn't work:
#Html.DropDownListFor(x => x.ContentGroupFKId,new SelectList(new List<Object> {new {value = null, text = "Select"} (SelectList)ViewBag.ContentGroup)
Best regards.
I don't think you can. Whatever value you provide is going to be used to generate html in the form of a select list, which doesn't support null. As long as you have a DropDownListFor, it is going to set a value, even if it is empty. The best thing you can do is make the first value a "Please select an item" option and set it to null server side.
There isn't a great way to add the "Please Select" option (at least none that I have seen. People are welcome to correct me though!), but there are a few ways to do it. One would be to create a dummy content group that just has a name and id.
var contentGroups = obj.GetContentGrouplist();
contentGroups.Insert(0, new ContentGroup{Id = "0", Name = "Please select a content group"};
ViewBag.ContentGroup = new SelectList(contentGroups, "Id", "Name");
Or you can create an object (which you would use anywhere you needed this functionality) that just holds a text and value property and then manually add all of your content groups to it, including the empty one.
class DropDownListOption{
public string Text{get;set;}
public string Value{get;set;}
}
then in your code
var contentGroups = obj.GetContentGrouplist();
var options = new List<DropDownListOption>();
options.Add(new DropDownListOption{ Id = "0", Text = "Please select a content group"};
foreach(var group in contentGroups)
{
options.Add(new DropDownListOption{ Id = group.Id, Text = group.Name};
}
ViewBag.ContentGroup = new SelectList(options, "Id", "Name");
Both of these options will work. I like the second option better because you can create a generic method of handling all drop down lists a certain way. You will have to handle ContentGroups with an ID of 0 as being null when the user submits the form, but at least it is a way of tracking it.
If I think of another way ill add it.
I have an enum, which is a mapping for a description of a property against an index in the database. I have a property on my ViewModel that represents an instance of that enum. I've tried both returning a list of enum instances, which means I do this:
#Html.DropDownListFor(m => m.CurrentFilter,
Model.FilterTypes.Select(entry =>
new SelectListItem{ Text = entry.ToString(), Value = ((int)entry).ToString()}),
new { #class = "normalcell", style = "WIDTH: 132px;" })
and returning a list of SelectListItems, which means I do this:
#Html.DropDownListFor(m => m.CurrentFilter,
Model.FilterTypes.Select(entry =>
new SelectListItem{ Text = entry.Text, Value = entry.Value, Selected = entry.Selected}),
new { #class = "normalcell", style = "WIDTH: 132px;" })
In the second case, when I debug, I am certain that the Selected property on the entry object is true for the correct item. In both cases, there is no 'selected' attribute written in to my HTML and so the correct item is not selected. I've also set a breakpoint, and CurrentFilter DOES have the correct value and the rest of my page renders appropriately, so it's finding the value.
I've written plenty of drop lists that work, using similar code, I can't for the life of me see why this does not work, no matter how I try to do it ?
I have also tried:
#Html.DropDownListFor(m => m.CurrentFilter,
Model.FilterTypes,
new { #class = "normalcell", style = "WIDTH: 132px;" })
which seems to me to be the logical way to do it ( return a list of SelectListItems and just do no processing in the page ), but the Selected property is still ignored.
Update:
I tried to do it this way:
#Html.DropDownList("CurrentFilter", Model.FilterTypes, new { #class = "normalcell", style = "WIDTH: 132px;" })
and just read the value out of the request. It's still the case that I am returning a list with only one item that has Selected == true, and it's still the case that MVC is ignoring it.
This works, not surprisingly, but I'd love to know why all the other things don't.
<select class="normalcell" id="CurrentFilter" name="CurrentFilter" style="WIDTH: 132px;">
#foreach (SelectListItem item in Model.FilterTypes)
{
if (item.Selected)
{
<option value="#item.Value" selected="selected">#item.Text</option>
}
else
{
<option value="#item.Value">#item.Text</option>
}
}
I believe the reason is that the MVC binding engine doesn't know how to deal with Enum values. I think you need to create a "proxy" property for your view model. Something like this...
public enum MyEnum { a, b, c, d };
public MyEnum EnumVal { get; private set; }
public string EnumProxy
{
get { return EnumVal.ToString(); }
set { EnumVal = (MyEnum)Enum.Parse(typeof(MyEnum), value); }
}
Then construct the drop-down list using the Enum names:
Type t = typeof(MyEnum);
var ddList = Enum.GetNames(t).Select(
item => new SelectListItem() { Text = item, Value = item }
).ToArray();
Now you should be able to use DropDownListFor normally:
#Html.DropDownListFor(model => model.EnumProxy, ddList)
I'm not sure if there's a neater solution. This one should work though.
My DDL tutorial shows how to use enums. See See my tutorial Working with the DropDownList Box and jQuery and My blog Cascading DropDownList in ASP.Net MVC Part 2 of the tutorial explains: When the string argument (the property to bind) and the SelectList object have the same name, the selected value is not used.
Darin has a SO post on another common reason the selected value is not display. See MVC DropDownList SelectedValue not displaying correctly
I'm building my first MVC application after years of doing webforms, and for some reason I am not able to make this work:
#Html.DropDownList("PriorityID", String.Empty, new {#class="textbox"} )
Error message:
System.Web.Mvc.HtmlHelper<SPDR.Models.Bug>' does not contain a definition for DropDownList and the best extension method overload System.Web.Mvc.Html.SelectExtensions.DropDownList(System.Web.Mvc.HtmlHelper, string, System.Collections.Generic.IEnumerable<System.Web.Mvc.SelectListItem>, object) has some invalid arguments
Any help greatly appreciated!
Looking at the controller, and learing a bit more about how MVC actually works, I was able to make sense of this.
My view was one of the auto-generated ones, and contained this line of code:
#Html.DropDownList("PriorityID", string.Empty)
To add html attributes, I needed to do something like this:
#Html.DropDownList("PriorityID", (IEnumerable<SelectListItem>)ViewBag.PriorityID, new { #class="dropdown" })
Thanks again to #Laurent for your help, I realise the question wasn't as clear as it could have been...
UPDATE:
A better way of doing this would be to use DropDownListFor where possible, that way you don't rely on a magic string for the name attribute
#Html.DropDownListFor(x => x.PriorityID, (IEnumerable<SelectListItem>)ViewBag.PriorityID, new { #class = "dropdown" })
As the signature from the error message implies, the second argument must be an IEnumerable, more specifically, an IEnumerable of SelectListItem. It is the list of choices. You can use the SelectList type, which is a IEnumerable of SelectListItem.
For a list with no choices:
#Html.DropDownList("PriorityID", new List<SelectListItem>(), new {#class="textbox"} )
For a list with a few choices:
#Html.DropDownList(
"PriorityID",
new List<SelectListItem>
{
new SelectListItem { Text = "High", Value = 1 },
new SelectListItem { Text = "Low", Value = 0 },
},
new {#class="textbox"})
Maybe this tutorial can be of help: How to create a DropDownList with ASP.NET MVC
If you are add more than argument ya dropdownlist in Asp.Net MVC.
When you Edit record or pass value in view bag.
Use this it will be work:-
#Html.DropDownList("CurrencyID",null,String.Empty, new { #class = "form-control-mandatory" })
There are some options in constructors look,
if you don't have dropdownList and you wanna insert CSS class you can use like
#Html.DropDownList("Country", null, "Choose-Category", new {#class="form-control"})
in this case Country is the name of your dropdown, null is for you aren't passing any generic list from your controller "Choose-Category" is selected item and last one in CSS class
if you don't wanna select any default option so simple replace "Choose-Category" with ""
You Can do it using jQuery
$("select").addClass("form-control")
here, Select is- html tag,
Form-control is- class name
#Html.DropDownList("SupplierId", "Select Supplier")
and here, SupplierId is ViewBagList,
Select Supplier is - Display Name
Simply Try this
#Html.DropDownList("PriorityID", (IEnumerable<SelectListItem>)ViewBag.PriorityID, new { #class="dropdown" })
But if you want a default value or no option value then you must have to try this one, because String.Empty will select that no value for you which will work as a -select- as default option
#Html.DropDownList("PriorityID", (IEnumerable<SelectListItem>)ViewBag.PriorityID, String.Empty, new { #class="dropdown" })
Try below code:
#Html.DropDownList("ProductTypeID",null,"",new { #class = "form-control"})
Try this:
#Html.DropDownList(
"country",
new[] {
new SelectListItem() { Value = "IN", Text = "India" },
new SelectListItem() { Value = "US", Text = "United States" }
},
"Country",
new { #class = "form-control",#selected = Model.Country}
)
You can simply do this:
#Html.DropDownList("PriorityID", null, new { #class="form-control"})
Try This
#Html.DropDownList("Id", null, new { #class = "ct-js-select ct-select-lg" })
I am using DropDownListFor to render a dropdown list in a view. Somehow the rendered list does not select the SelectListItem with Selected set to true.
In the controller action:
var selectList = sortedEntries.Select(entry => new SelectListItem
{
Selected = entry.Value.Equals(selectedValue),
Text = entry.Value,
Value = entry.Id
});
return View(new DropDownListModel
{
ListId = id,
SelectList = selectList,
OptionLabel = "Click to Select"
});
In the view:
<%= Html.DropDownListFor(m => m.ListId,
Model.SelectList,
Model.OptionLabel,
new {#class="someClass"}) %>
I have tried the following:
make sure that there is one and only one items with Selected set to true.
remove the option label argument.
remove the HTML attribute object.
use SelectList in DropDownListFor:
Html.DropDownListFor(m => m.ListId,
new SelectList(Model.SelectList, "Value", "Text",
new List<SelectListItem>(Model.SelectList).Find(s => s.Selected)),
new {#class="someClass"})
Any suggestions as to what went wrong?
EDIT:
more information:
This action is a child action, called by another view with HTML.RenderAction
DropDownListFor will always select the value that the listbox is for, so in this case it will look at the value of ListId and make that item in the list selected. If ListId is not found in the list, the first item (or default text) will be selected. If you want a list that selects based on the selected attribute use DropDownList (without the For, in that case you have to name it yourself).
So in your case this would work:
var selectList = sortedEntries.Select(entry => new SelectListItem
{
Text = entry.Value,
Value = entry.Id
});
return View(new DropDownListModel
{
ListId = selectedValue,
SelectList = selectList,
OptionLabel = "Click to Select"
});
I got the same problem on the same model (with the other models in the decision no problem)
Does not work:
#Html.DropDownListFor(o => o.Drivers.ValueListItems.Value, Model.Drivers.ValueListItems, new { size = Model.Drivers.ValueSizeList, Multiple = "multiple" })
Works perfectly, the elements selected:
#Html.DropDownListFor(o => o.Drivers.ValueListItems.ToDictionary(u=>u.Value).Values, Model.Drivers.ValueListItems, new { size = Model.Drivers.ValueSizeList, Multiple = "multiple" })
Try like this:
var selectList = sortedEntries.Select(entry => new SelectListItem
{
Text = entry.Value,
Value = entry.Id
});
return View(new DropDownListModel
{
// The drop down list is bound to ListId so simply set its value
// to some element value in the list and it will get automatically
// preselected
ListId = selectedValue,
SelectList = selectList,
OptionLabel = "Click to Select"
});
and in the view:
<%= Html.DropDownListFor(
m => m.ListId,
new SelectList(Model.SelectList, "Value", "Text"),
Model.OptionLabel,
new { #class = "someClass" }
) %>
There could be one more gotcha: you are trying to change the selected value in a POST action. For example you rendered a form, the user selected some value in the dropdown, submitted the form and in your POST action you do some processing on this selected value and when you redisplay the view you want the drop down list to have some other value selected. In this case you will have to remove the initial selection which is contained in the ModelState or the Html helper will ignore the selected value in the model:
// do this before returning the view and only if your scenario
// corresponds to what I described above
ModelState.Remove("ListId");
The solution for this problem is simpler that we all think...
All we need to do is set the property on the view model for the element that the dropdown is bound to - i.e: ListId = 3 for example
this way when we do this
Html.DropDownListFor(m => m.ListId,
new SelectList(Model.SelectList, "Value", "Text",
new List<SelectListItem>(Model.SelectList).Find(s => s.Selected)),
new {#class="someClass"})
the HtmlHelper will automatically pick up the default value to display on the DropDownList
simples!
Hope it may help you and all the others - like me! - that have lost a lot of time searching for a solution for this apparent issue.