TabPanel ignoring the tab I change to on postback

Question

User-718146471 posted

Hey folks, I know this has to be one we have all seen a time or two.  I'm trying to get my gridviews to not flicker when there is a partial post back so I'm using AjaxUpdatepanel with a timer as the asynch control.  What happens is the page no longer flickers.  However, when the page does its asynch postback, if I have another tab selected, teh tab index gets reset to 0.  Anyway, onto my code:

aspx:

        <asp:UpdatePanel ID="updGlobal" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="true">
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="Timer1" />
        </Triggers>
        <ContentTemplate>
            <cc1:TabContainer ID="TabContainer1" runat="server" OnActiveTabChanged="Tabs_ActiveTabChanged" Width="100%" ActiveTabIndex="0">

.cs

if (!IsPostBack)
    {
        try
        {
            TabContainer1.ActiveTabIndex = (int)ViewState["ActiveTab"];
        }
        catch
        {

        }
    }

    protected void Tabs_ActiveTabChanged(object sender, EventArgs e)
    {
        ViewState["ActiveTab"] = TabContainer1.ActiveTabIndex;
    }

Answer 1

User398825048 posted

May be the solution in the following link will help:-

http://stackoverflow.com/questions/4585567/tab-index-is-reset-in-updatepanel

Answer 2

User-417640953 posted

Hi,

I made a demo below, and it works fine my side. The TabContainer tabpanel index not been reset.

<div>
        <asp:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server"></asp:ToolkitScriptManager>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
            <Triggers>
                <asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick"  />
            </Triggers>
            <ContentTemplate>
                <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
                <asp:Timer ID="Timer1" runat="server" Interval="1000" OnTick="Timer1_Tick"></asp:Timer>
                <asp:TabContainer ID="TabContainer1" runat="server" OnActiveTabChanged="TabContainer1_ActiveTabChanged" >
                    <asp:TabPanel ID="Panel1" runat="server">
                        <HeaderTemplate>Header1</HeaderTemplate>
                        <ContentTemplate>
                            Panel1
                        </ContentTemplate>
                    </asp:TabPanel>
                    <asp:TabPanel ID="Panel2" runat="server">
                        <HeaderTemplate>Header2</HeaderTemplate>
                        <ContentTemplate>
                            Panel2
                        </ContentTemplate>
                    </asp:TabPanel>
                    <asp:TabPanel ID="Panel3" runat="server">
                        <HeaderTemplate>Header3</HeaderTemplate>
                        <ContentTemplate>
                            Panel3
                        </ContentTemplate>
                    </asp:TabPanel>
                </asp:TabContainer>
            </ContentTemplate>
        </asp:UpdatePanel>
    </div>

Code behind:

  protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Timer1_Tick(object sender, EventArgs e)
        {
            this.Label1.Text += "s";
        }

        protected void TabContainer1_ActiveTabChanged(object sender, EventArgs e)
        {
           // ViewState["ActiveTab"] = TabContainer1.ActiveTabIndex;

        }

Making sure you have not disable the ViewState of the page or parent container.

Thanks.

Best Regards!

Answer 3

User-718146471 posted

All good suggestions.  I discovered the real problem was I did not set autopostback="true" on the tab control.  Sometimes it is the stupidest little thing that can cause the most grief.