Download iFrame twice in asp AjaxToolkit TabContainer

Question

am using asp AjaxToolkitin my prjoect as below asp.net C#code.

<asp:UpdatePanel ID="UpdatePanelDemo" runat="server">
        <ContentTemplate>
            <ajax:TabContainer ID="tabMessage" runat="server" ActiveTabIndex="1" AutoPostBack="true"
                OnActiveTabChanged="tabMessage_ActiveTabChanged" CssClass="ajax__tab_blueGrad-theme">
                <ajax:TabPanel ID="TabMCompose" runat="server">
                    <HeaderTemplate>
                        <span style="padding-left: 5px; padding-right: 5px;">Compose </span>
                    </HeaderTemplate>
                    <ContentTemplate>
                    This Text not flickering or not loading twice // ***** 
                        <iframe id="IFrmCompose" runat="server" scrolling="no" frameborder="0" height="400px"
                            width="100%"></iframe>
                    </ContentTemplate>
                </ajax:TabPanel>
                <ajax:TabPanel ID="tabMInbox" runat="server">
                    <HeaderTemplate>
                        <span style="padding-left: 5px; padding-right: 5px;">Inbox (<span id="SpnIn" runat="server"></span>)</span>
                    </HeaderTemplate>
                    <ContentTemplate>
                        <iframe id="IFrmInbox" runat="server" scrolling="no" frameborder="0" height="400px"
                            width="100%"></iframe>
                    </ContentTemplate>
                </ajax:TabPanel>
            </ajax:TabContainer>
        </ContentTemplate>
   </asp:UpdatePanel>

Problem: When I use iFrameinside ajax TabContainer, and when the user moves from the 1st tab to the second tab, it seems that the page is loading twice and iFrameloading twice or it is flickering, but the text above iFrameis as shown above (" This text does not flicker or does not load twice ") does not flicker.

There seems to be some problem with iFrameand Ajax TabContainer.

Please let me know why this is happening.

Thank.

Answer 1

100% , , ViewState. SRM IFrame , IFrame , URL-, ( ).

. URL- ViewState , . SRC "about: blank", .

, - UpdatePanels/Ajax IFrames, AJAX, IFrames .

Answer 2

100% , , ViewState.

(! IsPostBack)  BindIt();