want to get the selected row id
object reference not set to an instance of an object
Dim abc As String = TryCast(gvDataBig.SelectedRow.FindControl("cmbShowName"), DropDownList).Text
<asp:GridView ID="gvDataBig" CssClass="mGrid" AlternatingRowStyle-CssClass="alt" DataKeyNames="SH_ID" Width="100%" Height="100%" runat="server" AutoGenerateColumns="False" >
<HeaderStyle />
<AlternatingRowStyle />
<columns>
<asp:BoundField DataField="SH_TIMEBAND" HeaderText="Timeband" ItemStyle-HorizontalAlign="Left" ItemStyle-Wrap="true" HeaderStyle-HorizontalAlign="Center" />
<asp:BoundField DataField="SH_NAME" HeaderText="ProgramName" ItemStyle-HorizontalAlign="Left" ItemStyle-Wrap="true" />
<asp:TemplateField HeaderText="dd" ItemStyle-Width="25px">
<ItemTemplate>
<asp:DropDownList ID="cmbShowName" Width="225px" AutoPostBack="True" OnSelectedIndexChanged="DropDown_SelectedIndexChanged" runat="server" CssClass="form-control">
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateField>
</columns>
</asp:GridView>
SQL = "UPDATE TICKER_SHOWNAME SET SH_NAME='" & fixQuotes(ddltype.SelectedItem.Text) & "' WHERE SH_ID='" & abc& "'"