Programmatically Select Multiple Items of an ASP.NET ListBox

Tweet

In one of the forums, a user recently asked how to select multiple items of an ASP.NET ListBox. Here’s how

<div>
    <asp:ListBox ID="ListBox1" runat="server">
        <asp:ListItem Value="One" />
        <asp:ListItem Value="Two" />
        <asp:ListItem Value="Three" />
        <asp:ListItem Value="Four" />
        <asp:ListItem Value="Five" />
    </asp:ListBox>
</div>    

C#

protected void Page_Load(object sender, EventArgs e)
{
    ListBox1.SelectionMode = ListSelectionMode.Multiple;
    for (int i = 0; i < ListBox1.Items.Count; i++)
    {
        if(i == 0 || i == 2 || i == 4)
        {
            ListBox1.Items[i].Selected = true;
        }
    }
}

VB.NET

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    ListBox1.SelectionMode = ListSelectionMode.Multiple
    For i As Integer = 0 To ListBox1.Items.Count - 1
        If i = 0 OrElse i = 2 OrElse i = 4 Then
            ListBox1.Items(i).Selected = True
        End If
    Next i
End Sub

The code shown above selects the first, third and fifth items of a ListBox as in the screenshot below

Tweet

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.