Hi,
there are a TabPanel tp and a GridPanel gp in the aspx, i hidden the gp. When click a button ,i want to render the gp to the tp ( .cs code behind),but there is a runtime error:'this.selModel.selectedData' is null. Now,'this' is gp.
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aspx:
<ext:TabPanel ID="TabPanel_Main" runat="server" Region="Center" Width="450" />

<ext:GridPanel
ID="Panel_Mux_Frame"
StoreID = "Store_Mux_Frame"
runat="server"
Width="350"
SelectionMemory = "Disabled"
Hidden="true"
Title="Mux_Frame">
<ColumnModel ID="report_ColumnMode" runat="server" >
<Columns>
<ext:RowNumbererColumn Width="20" />
<ext:Column Header="MuxFrame_ID" Sortable="true" Width="75" DataIndex="MuxFrame_ID" />
<ext:Column Header="Start_Time_Slot" Sortable="true" Width="75" DataIndex="Start_Time_Slot" />
<ext:Column Header="Time_Slot_Num" Sortable="true" Width="75" DataIndex="Time_Slot_Num" />
</Columns>
</ColumnModel>
<BottomBar>
<ext:PagingToolbar ID="PagingToolbar1" runat="server" PageSize="15" />
</BottomBar>
</ext:GridPanel>

.cs:
protected void Mux_Frame_Click(object sender, DirectEventArgs e)
{
Panel_Mux_Frame.Render(TabPanel_Main);

Panel_Mux_Frame.Reload();
}