How can I list date values as enumerable values list for ListBox

Question

I'm loading a ListBox from a model which looks like this

public class FilterModel
{
    public Learning TypeOfLearning { get; set; }
    public TeachingYear Teaching { get; set; }
}

public enum Learning
{
    All,
    Frameworks,
    Qualifications,
    Units,
    Standards
}

public enum TeachingYear
{
    2016/2017,
    2017/2018,
    2018/2019,
    2019/2020
}

The values are loaded into my ListBox as below

 @Html.DropDownList("LearningType", new SelectList(Enum.GetValues(typeof(Learning))),
                              "Select Learning Type", new { @style = "width: 350px" })

 @Html.DropDownList("TeachingYeare",
                              new SelectList(Enum.GetValues(typeof(TeachingYear))),
                              "Select Teaching Year", new { @style = "width: 350px" })

Learning works fine but TeachingYear objects to the numeric values which I've tried parsing but it still wont run. How do I set up my enum to correctly display the date range values?

There is an EnumDropDownList helper, that should do it – Davide Vitali Feb 28 '19 at 12:00 — Davide Vitali, Feb 28 '19 at 12:00

Davide Vitali · Accepted Answer · 2019-02-28T17:22:40.743

0

As per MSDN documentation,

An enumeration is a set of named constants whose underlying type is any integral type

Being constants, their name can't be defined using numbers as their first character, just like any other variable. Also, considering that every teaching year will always finish the year after it started, putting the ending year in the name itself is redundant. I suggest you should change the name and use attribute decorators like this:

using System.ComponentModel.DataAnnotations;    

public enum TeachingYear
{
    [Display(Name = "2016/2017")]
    _2016,
    [Display(Name = "2017/2018")]
    _2017,
    [Display(Name = "2018/2019")]
    _2018,
    [Display(Name = "2019/2020")]
    _2019
}

so that, when using the EnumDropDownListFor html helper, descriptions are automatically shown in the list, while values are bound to the object. See also this answer here.

EDIT: Considering your latest comment about the framework, in the view

@Html.GetEnumSelectList<TeachingYear>()

should do it, but I’ve never used .NET Core so you’d better check the relative MSDN documentation for proper usage.

edited Feb 28 '19 at 17:22

answered Feb 28 '19 at 12:29

Davide Vitali

1,017
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Thank you Davide, that is the nearest I have got so far. How can I get my drop down list to display 2016/2017 or 2016-2017 instead of _2016? – user616076 Feb 28 '19 at 13:44
@user616076 I edited my answer as to your comment. :) – Davide Vitali Feb 28 '19 at 14:01
Thank you for your help Davide, I added your changes but I still get _2016... in my list. I'm using @Html.DropDownList("TeachingYear", new SelectList(Enum.GetValues(typeof(TeachingYear))), "Select Teaching Year", new { @style = "width: 350px" }) in my view. I don't seem to be able to use EnumDropDownListFor – user616076 Feb 28 '19 at 15:53
What MVC version are you using? – Davide Vitali Feb 28 '19 at 15:57
I'm using .Net Core 2.1 – user616076 Feb 28 '19 at 16:09

score 0 · Answer 2 · answered Mar 01 '19 at 09:29

In your View , you could try the following changes :

        <div class="form-group">
            <select asp-for="learning"
                    asp-items="@Html.GetEnumSelectList<Learning>()">
                <option>Select Learning Type</option>
            </select>
        </div>
        <div class="form-group">
            <select asp-for="learning"
                    asp-items="@Html.GetEnumSelectList<TeachingYear>()">
                <option>Select Teaching Year</option>
            </select>
        </div>

How can I list date values as enumerable values list for ListBox

2 Answers2