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How to use ListBox in asp.net c#

ListBox Web Server Control
The ListBox is an ASP.NET list web server control. ListBox control renders a list box that allows single or multiple-item selection. ListBox SelectionMode property gets or sets the selection mode of ListBox control. SelectionMode property has two possible values those are Single and Multiple.

ASP.NET developers can programmatically change the ListBox selection mode by setting the ListSelectionMode enumeration value. Multiple modes specify that multiple items can be selected from ListBox control.

ListBox Row property gets or sets the number of rows displayed in ListBox. That means the Row property specifies the height of ListBox control. ListBox has an Item collection that contains all ListItem objects. each ListItem object represents an item in ListBox control. We can add or remove ListItem programmatically at run time in ListBox.

We can populate a ListBox with items at design time using declarative syntax by putting ListItem objects between opening and closing ListBox tags. ListBox supports data binding. So we can populate ListBox with items using various data sources such as SqlDataSource, LinqDataSource, ObjectDataSource, AccessDataSource, etc.

The ListBox DataBind method allows us to bind data source object with ListBox control programmatically. ListBox DataTextField and DataValueFiled property specify which field of the data source to bind to the Text and Value property of ListBox.

ListBox AutoPostBack property and SelectedIndexChanged event allow us to automatically post back to the web server when the user change selection of ListBox items.
ListBoxHowToUse.aspx

<%@ Page Language="C#" %>

<!DOCTYPE html>

<script runat="server">
    protected void ListBox1_SelectedIndexChanged(object sender, System.EventArgs e) {
        Label1.Text = "Your favorite color is : " +
            ListBox1.SelectedItem.Text.ToString();
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>How to use ListBox control in asp.net</title>
</head>
<body style="padding:25px">
    <form id="form1" runat="server">
    <div>
        <h2 style="color:MidnightBlue; font-style:italic;">      
            How to use ListBox control
        </h2>      
        <hr width="450" align="left" color="Gainsboro" />
        <asp:Label 
            ID="Label1" 
            runat="server" 
            Font-Size="XX-Large" 
            ForeColor="DarkOliveGreen"
            Font-Italic="true"
            />
        <br /><br />
        <asp:Label 
            ID="Label2" 
            runat="server" 
            Text="Choose a color" 
            AssociatedControlID="ListBox1"
            Font-Bold="true"
            ForeColor="Navy"
            Font-Size="X-Large"
            />
        <br />
        <asp:ListBox 
            ID="ListBox1" 
            runat="server" 
            AutoPostBack="true" 
            Font-Size="X-Large"
            Font-Names="Comic Sans MS"
            Rows="5"
            ForeColor="Tomato"
            Width="350"
            OnSelectedIndexChanged="ListBox1_SelectedIndexChanged"
            >
            <asp:ListItem>DarkCyan</asp:ListItem>
            <asp:ListItem>DarkBlue</asp:ListItem>
            <asp:ListItem>DarkGoldenrod</asp:ListItem>
            <asp:ListItem>DarkGray</asp:ListItem>
            <asp:ListItem>DarkGreen</asp:ListItem>
            <asp:ListItem>DarkKhaki</asp:ListItem>
            <asp:ListItem>DarkMagenta</asp:ListItem>
        </asp:ListBox>
    </div>
    </form>
</body>
</html>
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