Question

This is our code:

  <div>
 <table style="width: 349px">
    <tr>
    <td class="style1">
        <asp:ListBox ID="leftbox" runat="server" Height="114px" Width="212px" 
            SelectionMode="Multiple" AutoPostBack="True">
        </asp:ListBox>
    </td>
    <td>
        <asp:Button ID="Button1" runat="server" Text=">>" onclick="Button1_Click" /><br />
        <asp:Button ID="Button2" runat="server" Text="<<" onclick="Button2_Click" />
    </td>
    <td>
        <asp:ListBox ID="rightbox" runat="server" Height="117px" Width="231px" 
            SelectionMode="Multiple" AutoPostBack="True"></asp:ListBox>
    </td>

    </tr>
</table>
</div>    

The code behind is:

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        List<string> list= GetNameList();
        leftbox.DataSource = list;
        leftbox.DataBind();             
    }
}

private static List<string> GetNameList()
{
    List<string> list = new List<string>();
    list.Add("keerthana");
    list.Add("sirisha");
    list.Add("anusha");
    list.Add("Anuradha");
    list.Add("Bhavani");
    list.Add("divya");
    list.Sort();
    return list;
}

Please tell me how to add two or more selected items one by one from leftbox to rightbox, without using server-side code (as below):

protected void Button1_Click(object sender, EventArgs e)
{
    if (leftbox.SelectedIndex != -1)
    {
        rightbox.Items.Add(leftbox.SelectedItem.Text);
        leftbox.Items.Remove(leftbox.SelectedItem.Text);
    }
}

Thanks in advance…

Answer 1

Here is Linq way of get selected items form ListBox

var selectedItems =  leftbox.Items.OfType<ListItem>().Where(item => item.Selected).ToList();

then you can add all selected values to rightbox and finally remove from leftbox

EDIT

protected void Button1_Click(object sender, EventArgs e)
{
    List<ListItem> selectedItems = new List<ListItem>();
    if (leftbox.SelectedIndex >= 0)
    {
        for (int i = 0; i < leftbox.Items.Count; i++)
        {
            if (leftbox.Items[i].Selected)
            {
                    selectedItems.Add(leftbox.Items[i]);
            }
        }

    }

    for (int i = 0; i < selectedItems.Count; i++)
    {
        if (!rightbox.Items.Contains(selectedItems[i]))
            rightbox.Items.Add(selectedItems[i]);
        leftbox.Items.Remove(selectedItems[i]);
    }

}