format the items in a selectlist - model-view-controller

Question

i have seen other posts with answers to this but i cannot get any of them to work for me.. so. this is in my controller->
ViewData["TARGET_DATE"] = new SelectList((from n in _db.ACTION_PLANs select n).ToList(), "TARGET_DATE", "TARGET_DATE");
i want to be able to apply a format on the dates that come back from the db, my DDL looks like this
<td><%=Html.DropDownList("TARGET_DATE", "All")%></td>
does anyone know if there is a way to loop through and format each date, or apply a format to them all. or what would be the best way to do this, if u need more code i can provide, what i really want is to display the date without the time with it. thanks in advance.

Answer 1

I know this post is old, but I ran across it while searching for an answer to the same problem. I ended up writing a FormattableSelectList class that takes a format string as a parameter, and then formats that output of the select list. Here's a sample of how to use it.
#Html.DropDownFor(
o => o.SomeProperty,
new FormattableSelectList(ViewBag.MyItems, "ID", "Time", "{0:f}"),
"Choose a Time"
)
I wrote a short post about it at http://www.jpolete.me/2011/11/16/a-formattable-selectlist-for-net-mvc/. Here's the code for it.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Collections;
using System.Web.UI;
using System.Globalization;
public class FormattableSelectList : SelectList
{
private string _FormatString;
public FormattableSelectList(IEnumerable items, string dataValueField, string dataTextField, string formatString)
: base(items, dataValueField, dataTextField)
{
_FormatString = formatString;
}
public FormattableSelectList(IEnumerable items, string dataValueField, string dataTextField, string formatString, object selectedValue)
: base(items, dataValueField, dataTextField, selectedValue)
{
_FormatString = formatString;
}
public override IEnumerator<SelectListItem> GetEnumerator()
{
return ((!String.IsNullOrEmpty(DataValueField)) ?
GetListItemsWithValueField() :
GetListItemsWithoutValueField()).GetEnumerator();
}
private IList<SelectListItem> GetListItemsWithValueField()
{
HashSet<string> selectedValues = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
if (SelectedValues != null)
{
selectedValues.UnionWith(from object value in SelectedValues select Convert.ToString(value, CultureInfo.CurrentCulture));
}
var listItems = from object item in Items
let value = Eval(item, DataValueField, null)
select new SelectListItem
{
Value = value,
Text = Eval(item, DataTextField, _FormatString),
Selected = selectedValues.Contains(value)
};
return listItems.ToList();
}
private IList<SelectListItem> GetListItemsWithoutValueField()
{
HashSet<object> selectedValues = new HashSet<object>();
if (SelectedValues != null)
{
selectedValues.UnionWith(SelectedValues.Cast<object>());
}
var listItems = from object item in Items
select new SelectListItem
{
Text = Eval(item, DataTextField, _FormatString),
Selected = selectedValues.Contains(item)
};
return listItems.ToList();
}
private static string Eval(object container, string expression, string formatString)
{
object value = container;
if (!String.IsNullOrEmpty(expression))
{
value = DataBinder.Eval(container, expression);
}
string stringValue;
if (formatString == null)
{
stringValue = Convert.ToString(value, CultureInfo.CurrentCulture);
}
else
{
stringValue = String.Format(formatString, value);
}
return stringValue;
}
}

Answer 2

Here is how I implemented the class above. My client was looking for two dropdownlists containing Start time and End time. In MVC4
Model:
[Display(Name = "Time (From):")]
public int FromTimeId { get; set; }
[Display(Name = "Time (To):")]
public int ToTimeId { get; set; }
public virtual FromTime FromTime { get; set; }
public virtual ToTime ToTime { get; set; }
Controller:
public ActionResult Create()
{
ViewBag.FromTimes = db.FromTimes;
ViewBag.ToTimes = db.ToTimes;
}
View:
<div class="editor-field">
#Html.DropDownListFor(model => model.FromTimeId, new Namespace.FormattableSelectList(ViewBag.FromTimes, "FromTimeId", "FromTimeName", "{0:h:mm tt}"))<br />
#Html.ValidationMessageFor(model => model.FromTimeId)
</div>
</td>
<td>
<div class="editor-label">
#Html.LabelFor(model => model.ToTimeId, "To Time:")
</div>
<div class="editor-field">
#Html.DropDownListFor(model => model.ToTimeId, new Namespace.FormattableSelectList(ViewBag.ToTimes, "ToTimeId", "ToTimeName", "{0:h:mm tt}"))<br />
#Html.ValidationMessageFor(model => model.ToTimeId)
</div>