Bind dropdownlist to enum : The Official Microsoft ASP.NET Forums

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Bind dropdownlist to enum

Jun 02, 2008 03:24 PM|LINK

I want to bind the value and the name of the enum to the dropdownlist. I've been looking around about how to do this, and found some examples, but it's not working for me for some reason:

public enum Salutations
{
    Mr = 1,
    Ms = 2,
    Mrs = 3
}








string[] names = Enum.GetNames(typeof(Salutations));
Array values = Enum.GetValues(typeof(Salutations));
        

for(int i=0; inew ListItem(names[i], values[i].ToString());
     ddlSalutations1.Items.Add(item);
}

The problem is trying to access the value in values. I can't do it for an Array. How can I modify this?

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Re: Bind dropdownlist to enum

Jun 02, 2008 03:44 PM|LINK

Here are some methods I wrote to bind enum's to dropdownlists

/// <summary>
        /// Pass in a DropDownList and typeof(YourEnum) as parameters to auto-bind a dropdownlist to an enum
        /// </summary>
        /// <param name="ddl">ddlMyDropDownList</param>
        /// <param name="enumType">typeof(MyEnum)</param>
        /// <param name="retainSelected">true/false indicating if the currently selected item should remain selected</param>
        public static void BindEnum2DropDownList(DropDownList ddl, Type enumType, bool retainSelected)
        {
            // retain the currently selected item if possible
            string currentlySelectedValue = string.Empty;
            if(retainSelected)
                currentlySelectedValue = ddl.SelectedValue;


            ddl.DataSource = WilsToolbox.EnumHelper.GetListItemsFromEnum(enumType);
            ddl.DataBind();
            



            // in the event that there was a selected item, keep it.
            if (currentlySelectedValue != string.Empty && retainSelected == true)
            {
                ddl.ClearSelection();
                ddl.Items.FindByText(currentlySelectedValue).Selected = true;
            }
        }


        public static ListItemCollection GetListItemsFromEnum(Type enumType)
        {
            // container to be returned
            ListItemCollection items = new ListItemCollection();
            // break down the enumerator items into key/value pairs
            string[] names = Enum.GetNames(enumType);
            Array values = Enum.GetValues(enumType);
            // piece together the key/pairs into the listitem collection
            for (int i = 0; i <= names.Length - 1; i++)
            {
                items.Add(new ListItem(names[i], values.GetValue(i).ToString()));
            }
            // return it
            return items;
        }

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ecbruck

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Re: Bind dropdownlist to enum

Jun 02, 2008 03:57 PM|LINK

Here's an example:

ASPX

<%@ page language="C#" masterpagefile="~/MasterPages/Default.master" autoeventwireup="true"
	codefile="BindToEnum.aspx.cs" inherits="DropDownList_BindToEnum" title="DropDownList: Bind To Enum" %>


<asp:content id="Content1" contentplaceholderid="ContentPlaceHolder1" runat="Server">
	<asp:dropdownlist id="DropDownList1" runat="server">
	</asp:dropdownlist>
</asp:content>

CODE-BEHIND

using System;
using System.Web.UI.WebControls;

public partial class DropDownList_BindToEnum : System.Web.UI.Page
{
	private enum Salutations { Mr = 1, Ms = 2, Mrs = 3 };

	protected void Page_Load(object sender, EventArgs e)
    {
		if (!this.IsPostBack)
		{
			string[] names = Enum.GetNames(typeof(Salutations));
			Array values = Enum.GetValues(typeof(Salutations));

			for (int i = 0; i <= names.Length - 1; i++)
			{
				DropDownList1.Items.Add(new ListItem(names[i], Convert.ToInt32(values.GetValue(i)).ToString()));
			}
		}
    }
}

Thanks, Ed

Microsoft MVP - ASP.NET

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gbogea

Contributor

4019 Points

576 Posts

Re: Bind dropdownlist to enum

Jun 02, 2008 04:04 PM|LINK

You can create a method to help you convert your enum into a hashtable and then bind it to the ddl:

protected void Page_Load(object sender, EventArgs e)
    {
        Hashtable ht = GetEnumForBind(typeof(Salutations));
        DropDownList1.DataSource = ht;
        DropDownList1.DataTextField = "value";
        DropDownList1.DataValueField = "key";


        DropDownList1.DataBind();
        

    }


    public Hashtable GetEnumForBind(Type enumeration)
    {
        string[] names = Enum.GetNames(enumeration);
        Array values = Enum.GetValues(enumeration);
        Hashtable ht = new Hashtable();
        for (int i = 0; i < names.Length; i++)
        {
            ht.Add(Convert.ToInt32(values.GetValue(i)).ToString(), names[i]);
        }
        return ht;
    }

Gabriel Bogéa (http://www.gbogea.com)
-----------------
Please 'Mark as Answer' the post(s) that helped you

Marked as answer by Apples on Jun 02, 2008 06:13 PM

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Apples

Member

75 Points

452 Posts

Re: Bind dropdownlist to enum

Jun 02, 2008 06:13 PM|LINK

That worked great, thank you.

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mattaniah

Member

5 Points

10 Posts

Re: Bind dropdownlist to enum

Jul 10, 2008 01:34 PM|LINK

Damn you are good. Thanks Alot.

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LastPhoenix

Member

15 Points

16 Posts

Re: Bind dropdownlist to enum

Dec 02, 2009 08:38 AM|LINK

Why not use like this to be able pass every listcontrol :

public static void BindToEnum(Type enumType, ListControl lc)
        {
            // get the names from the enumeration
            string[] names = Enum.GetNames(enumType);
            // get the values from the enumeration
            Array values = Enum.GetValues(enumType);
            // turn it into a hash table
            Hashtable ht = new Hashtable();
            for (int i = 0; i < names.Length; i++)
                // note the cast to integer here is important
                // otherwise we'll just get the enum string back again
                ht.Add(names[i], (int)values.GetValue(i));
            // return the dictionary to be bound to
            lc.DataSource = ht;
            lc.DataTextField = "Key";
            lc.DataValueField = "Value";
            lc.DataBind();
        }

And use just as simple as :

BindToEnum(typeof(NewsType), DropDownList1);
BindToEnum(typeof(NewsType), CheckBoxList1);
BindToEnum(typeof(NewsType), RadoButtonList1);

Edited by LastPhoenix on Dec 02, 2009 08:41 AM
Edited by LastPhoenix on Dec 02, 2009 08:44 AM
Edited by LastPhoenix on Dec 02, 2009 08:45 AM
Edited by LastPhoenix on Dec 02, 2009 08:55 AM

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Anithaol

Member

5 Points

4 Posts

Re: Bind dropdownlist to enum

Feb 09, 2010 03:55 PM|LINK

Hi,

That was a Good Example to bind to any ListControl

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neilinfl

Member

2 Points

3 Posts

Re: Bind dropdownlist to enum

Oct 16, 2010 07:46 PM|LINK

I like it! But what is I wanted to decorate my enumeration with a system.componantmodel.description and use the description as the value:

<div style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow-x: hidden; overflow-y: hidden;" id="_mcePaste">public enum Divisions : int</div> <div style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow-x: hidden; overflow-y: hidden;" id="_mcePaste"> {</div> <div style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow-x: hidden; overflow-y: hidden;" id="_mcePaste"></div> <div style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow-x: hidden; overflow-y: hidden;" id="_mcePaste"> [Description("Restaurant")]</div> <div style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow-x: hidden; overflow-y: hidden;" id="_mcePaste"> Restaurant= 0,</div> <div style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow-x: hidden; overflow-y: hidden;" id="_mcePaste"> [Description("Residential")]</div> <div style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow-x: hidden; overflow-y: hidden;" id="_mcePaste"> Residential = 1,</div> <div style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow-x: hidden; overflow-y: hidden;" id="_mcePaste"> [Description("Commercial")]</div> <div style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow-x: hidden; overflow-y: hidden;" id="_mcePaste"> Commercial = 2</div> <div style="position: absolute; left: -10000px; top: 0px; width: 1px; height: 1px; overflow-x: hidden; overflow-y: hidden;" id="_mcePaste"> }</div>

public enum Divisions : int

{

[Description("Fruit & Vegetables")]

Vegetables= 0,

[Description("Beef")]

Beef = 1,

[Description("Poultry")]

Poultry= 2

}

So the key would be 0 and the value would be Fruit and Vegetables

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Apples

Bind dropdownlist to enum

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Apples

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