ASP:Listbox – How To Populate a Listbox from a C# Generic List

Posted March 6, 2007
Filed under: ASP:NET, C#, Internet | Tags: , , , , , |

The guys over at ASPAlliance did an excellent article on user the ASP:ListBox with VB.NET. The article can be viewed at ASPAlliance. Which is really great if you are using VB.NET. The article makes it very easy to modify for use with C#.

Listbox web server control is equivalent to the <Select> tag in HTML. This control will be very useful to get inputs from user, were all values are pre-defined. For eg: inorder to accept the “State in which the user is living”, we can have a list of all states available. In this session, we will learn how to populate a listbox control.

Listbox – How to populate a Listbox from a List Generic.
Populating a listbox from an existing C# List Generic is very easy.

<%@ Import Namespace=”System.Collections.Generic” %>
<script language=”c#” runat=”server”>
private List<MyList> thelist;
protected void Page_Load(object sender, System.EventArgs e)
{
if (!IsPostBack)
this.BindData();
}private void BindData()
{
// code to populate listbox from generic list
MyCollection mc = new MyCollection(); \\ this is where my getStates function is.
thelist = mc.getStates();

foreach (MyList v in thelist)
{
ListItem li = new ListItem();
li.Value = v.StateCode;
li.Text = v.StateName;
mylist.Items.Add(li);
li = null;
}
}
</script>

<html>
<head>
<title>Listbox Control</title>
</head>
<body>
<form id=”form1″ runat=”server”>

<asp:ListBox ID=”mylist” runat=”server”></asp:ListBox>
</form>
</body>
</html>

1 comment so far

  1. Joe on March 8, 2007

    This is not the only way to do this. One thing I didn’t point out is that I had to filter out certain records. His original looked more like this…

    foreach (MyList v in thelist)
    {
    if ( v.StateCode != “SC” || v.StateCode != “NC” )
    {
    ListItem li = new ListItem();
    li.Value = v.StateCode;
    li.Text = v.StateName;
    mylist.Items.Add(li);
    li = null;
    }
    }


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