If you put a radspreadsheet inside a radtabstrip with multipage, the controls do not render properly. In my scenario, I have a tabstrip embedded within a tabstrip, and a grid in the nested tabstrip. That works fine. Once you put a spreadsheet control in the multipage, the controls do not render properly. However, I was able to reproduce the results with the first scenario above, which is the most simple.
<script> function OnClientTabSelected(sender, eventArgs) { var spread = $find("<%=RadSpreadsheet1.ClientID%>"); spread._widget.refresh(); }</script><telerik:RadTabStrip ID="RadTabStrip1" RenderMode="Lightweight" OnClientTabSelected="OnClientTabSelected" runat="server" MultiPageID="RadMultiPage1"> <Tabs> <telerik:RadTab Text="Placeholder"> </telerik:RadTab> <telerik:RadTab Text="Spreadsheet"> </telerik:RadTab> </Tabs></telerik:RadTabStrip><telerik:RadMultiPage ID="RadMultiPage1" runat="server"> <telerik:RadPageView ID="RadPageView1" runat="server" Selected="true"> <asp:Label ID="Label1" runat="server" Text="Placeholder"> </asp:Label> </telerik:RadPageView> <telerik:RadPageView ID="RadPageView2" runat="server"> <telerik:RadSpreadsheet ID="RadSpreadsheet1" runat="server"> </telerik:RadSpreadsheet> </telerik:RadPageView></telerik:RadMultiPage>I have the same issue. Here is a simple example...
<telerik:RadTabStrip ID="RadTabStrip1"
runat="server"
MultiPageID="RadMultiPage1">
<Tabs>
<telerik:RadTab Text="Placeholder">
</telerik:RadTab>
<telerik:RadTab Text="Spreadsheet">
</telerik:RadTab>
</Tabs>
</telerik:RadTabStrip>
<telerik:RadMultiPage ID="RadMultiPage1"
runat="server">
<telerik:RadPageView ID="RadPageView1"
runat="server"
Selected="true">
<asp:Label ID="Label1"
runat="server"
Text="Placeholder">
</asp:Label>
</telerik:RadPageView>
<telerik:RadPageView ID="RadPageView2"
runat="server">
<telerik:RadSpreadsheet ID="RadSpreadsheet1"
runat="server">
</telerik:RadSpreadsheet>
</telerik:RadPageView>
</telerik:RadMultiPage>