Sort Items in an ASP.NET DropDownList using LINQ

Have you been looking out for a way to sort the items of an ASP.NET DropDownList using LINQ? Here’s a LINQ solution:

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Sorting DropDownList Items</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:DropDownList ID="DropDownList1" runat="server">
            <asp:ListItem Text="Item3"></asp:ListItem>
            <asp:ListItem Text="Item1"></asp:ListItem>
            <asp:ListItem Text="Item4"></asp:ListItem>
            <asp:ListItem Text="Item5"></asp:ListItem>
            <asp:ListItem Text="Item2"></asp:ListItem>
        </asp:DropDownList>
        <br />
        <asp:Button ID="btnSort" runat="server" Text="Sort"
            onclick="btnSort_Click"/>
    </div>
    </form>
</body>
</html>

protected void btnSort_Click(object sender, EventArgs e)
{
List<string> listItems =
   DropDownList1.Items.Cast<ListItem>().Select(item => item.Text).ToList();
listItems.Sort((a, b) => string.Compare(a, b));
DropDownList1.DataSource = listItems;
DropDownList1.DataBind();
}

VB.NET

Protected Sub btnSort_Click(ByVal sender As Object, ByVal e As EventArgs)
    Dim listItems As List(Of String) = _
    DDL.Items.Cast(Of ListItem)().Select(Function(item) item.Text).ToList()
    listItems.Sort(Function(a, b) String.Compare(a, b))
    DDL.DataSource = listItems
    DDL.DataBind()
End Sub

Before Sorting

After Sorting

About The Author

Suprotim Agarwal, Developer Technologies MVP (Microsoft Most Valuable Professional) is the founder and contributor for DevCurry, DotNetCurry and SQLServerCurry. He is the Chief Editor of a Developer Magazine called DNC Magazine. He has also authored two Books - 51 Recipes using jQuery with ASP.NET Controls. and The Absolutely Awesome jQuery CookBook.

Follow him on twitter @suprotimagarwal.

4 comments:

Anonymous said...: great stuff. Thanks for sharing.
http://taphop.net
http://tatca.vn; September 23, 2009 at 12:43 AM
Raunak Jhawar said...: Thank you very much; January 5, 2010 at 5:00 AM
Anonymous said...: This idea works except that it destroys any value items that was part of the list.; December 23, 2012 at 6:30 AM
Unknown said...: Does anyone have a solution for losing the values portion of the list items?; November 21, 2014 at 7:04 AM