ListBox

@inherits ControlComponent

<asp.ListBox @ref="this.listBox"
                                            Rows="6"
                                            Width="100px"
                                            SelectionMode="ListSelectionMode.Single">
                                            <asp.ListItem>Item 1</asp.ListItem>
                                            <asp.ListItem>Item 2</asp.ListItem>
                                            <asp.ListItem>Item 3</asp.ListItem>
                                            <asp.ListItem>Item 4</asp.ListItem>
                                            <asp.ListItem>Item 5</asp.ListItem>
                                            <asp.ListItem>Item 6</asp.ListItem>
</asp.ListBox>

<br />
<br />

<asp.Button Text="Submit"
                                            OnClick="this.SubmitBtn_Click" />

<asp.Label @ref="this.label"
                                            FontNames="Verdana"
                                            FontSize="10pt" />

@code {
                                            private ListBox listBox;
                                            private Label label;

                                            protected void SubmitBtn_Click(object sender, EventArgs e)
    {
                                            if (listBox.SelectedIndex > -1)
            label.Text = "You chose: " + listBox.SelectedItem.Text;
    }
}

@inherits ControlComponent

<asp.ListBox @ref="this.listBox"
                                            Rows="6"
                                            Width="100px"
                                            SelectionMode="ListSelectionMode.Multiple">
                                            <asp.ListItem>Item 1</asp.ListItem>
                                            <asp.ListItem>Item 2</asp.ListItem>
                                            <asp.ListItem>Item 3</asp.ListItem>
                                            <asp.ListItem>Item 4</asp.ListItem>
                                            <asp.ListItem>Item 5</asp.ListItem>
                                            <asp.ListItem>Item 6</asp.ListItem>
</asp.ListBox>

<br />
<br />

<asp.Button Text="Submit"
                                            OnClick="this.SubmitBtn_Click" />

<asp.Label @ref="this.label"
                                            FontNames="Verdana"
                                            FontSize="10pt" />

@code {
                                            private ListBox listBox;
                                            private Label label;

                                            protected void SubmitBtn_Click(object sender, EventArgs e)
    {
                                            string msg = "";
                                            foreach (ListItem li in listBox.Items)
        {
                                            if (li.Selected == true)
            {
                msg += "<br>" + li.Text + " is selected.";
            }
        }
        label.Text = msg;
    }
}

@using System.Collections
@inherits ControlComponent

<asp.ListBox @ref="this.listBox"
                                            DataSourceID="FreeDataSource1"
                                            Width="100px">
</asp.ListBox>

<asp.FreeDataSource ID="FreeDataSource1" OnExecuteSelected="sender => this.CreateDataSource()" />

<br />
<br />

<asp.Button Text="Submit"
                                            OnClick="this.SubmitBtn_Click" />

<asp.Label @ref="this.label"
                                            FontNames="Verdana"
                                            FontSize="10pt" />

@code {
                                            private ListBox listBox;
                                            private Label label;

                                            protected ICollection CreateDataSource()
    {
        ArrayList values = new ArrayList();
        values.Add("Item 1");
        values.Add("Item 2");
        values.Add("Item 3");
        values.Add("Item 4");
        values.Add("Item 5");
        values.Add("Item 6");
                                            return values;
    }

                                            protected void SubmitBtn_Click(object sender, EventArgs e)
    {
                                            if (listBox.SelectedIndex > -1)
            label.Text = "You chose: " + listBox.SelectedItem.Text;
    }
}