Question

I have follow two listboxes and and a left and right button.. which are contained in a updatepanel. The only problem is when clicking on the left or right button the page refreshes which is not desired.

<asp:UpdatePanel runat="server" ID="ExportUpdatePanel">
<ContentTemplate>
    <div class="exportWrapper">
    <table class="exportFilter">
        <tr>
            <td>
                <h2>
                    <%= ExportSelectDateLabel %></h2>
            </td>
        </tr>
        <tr>
            <td>
                <label>
                    <%= ExportFromDateLabel %></label>
                <asp:TextBox runat="server" ID="exportFilterFromDate" CssClass="exportDates"></asp:TextBox>
            </td>
        </tr>
        <tr>
            <td>
                <label>
                    <%= ExportToDateLabel %></label>
                <asp:TextBox runat="server" ID="exportFilterToDate" CssClass="exportDates"></asp:TextBox>
            </td>
        </tr>
    </table>
    <table class="exportFilter">
        <tr>
            <td colspan="3">
                <h2>
                    <%= ExportSelectColumnsLabel %></h2>
            </td>
        </tr>
        <tr>
            <td>
                <label>
                    <%= ExportAvailableColumnLabel %></label>
            </td>
            <td>
            </td>
            <td>
                <label>
                    <%= ExportSelectedColumnLabel %></label>
            </td>
        </tr>
        <tr>
            <td>
                <asp:ListBox runat="server" ID="exportFilterAvailableColumns" SelectionMode="Multiple" CssClass="exportListBox">
                </asp:ListBox>
            </td>
            <td class="exportButtonsTd">
                <div>
                    <asp:LinkButton runat="server" OnClick="MoveSelectedClick"><span><img src="/images/source/arrow-right.png" alt="Move Right"/></span></asp:LinkButton>
                </div>
                <div class="mt_10">
                    <asp:LinkButton runat="server" OnClick="RemoveSelectedClick"><span><img src="/images/source/arrow-left.png" alt="Move Left"/></span></asp:LinkButton>
                </div>
            </td>
            <td id="exportedSelectedColumn">
                <asp:ListBox runat="server" ID="exportFilterSelectedColumns" SelectionMode="Multiple" CssClass="exportListBox">
                </asp:ListBox>
            </td>
        </tr>
    </table>
</div>
</ContentTemplate>
</asp:UpdatePanel>

Any ideas ?

Answer 1

As per your code ExportUpdatePanel section will refresh when you click on link button inside UpdatePanel. it is not full page refresh. default update mode of update panel is always. that means:
the UpdatePanel control’s content is updated on every postback that originates from anywhere on the page. This includes asynchronous postbacks from controls that are inside other UpdatePanel controls and postbacks from controls that are not inside UpdatePanel controls.

here is sample test:

<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
            <asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" />
            <asp:Label ID="Label2" runat="server" Text="Label"></asp:Label>
        </ContentTemplate>
</asp:UpdatePanel> 

On click event both Label1 and Label2 will update.

protected void Button1_Click(object sender, EventArgs e)
{
    Label1.Text = DateTime.Now.ToLongTimeString();
    Label2.Text = DateTime.Now.ToLongTimeString();
}

but only Label2 will change because it will refresh by the update panel.