当我点击gridview gridview值的编辑按钮在文本框中重试时如何可能

<div>
       <table>
           <tr>
               <td>Country Name</td>
               <td>
                   <asp:DropDownList ID="ddlstCountry" runat="server" Width="100%">
                   </asp:DropDownList>
               </td>
           </tr>
           <tr>
               <td>State Name</td>
               <td style="margin-left: 80px">
                   <asp:TextBox ID="txtState" runat="server" Width="100%"></asp:TextBox>
               </td>
           </tr>
           <tr>
               <td>

               </td>
               <td>
                   <asp:Button ID="btnSubmit" runat="server" Text="Submit"

                       onclick="btnSubmit_Click" />
               </td>
           </tr>
       </table>

       <asp:GridView ID="GvState" runat="server" AutoGenerateColumns="False"

           DataKeyNames="StateId" Width="30%" onrowcommand="GvState_RowCommand">
           <RowStyle HorizontalAlign="Center" />
           <Columns>
               <asp:TemplateField HeaderText="StateId">
                   <ItemTemplate>
                       <asp:Label ID="lblStateId" runat="server" Text='<%# Eval("StateId") %>'></asp:Label>
                   </ItemTemplate>
               </asp:TemplateField>
               <asp:TemplateField HeaderText="StateName">
                   <ItemTemplate>
                       <asp:Label ID="lblStateName" runat="server" Text='<%# Eval("StateName") %>'></asp:Label>
                   </ItemTemplate>
               </asp:TemplateField>
               <asp:TemplateField HeaderText="CountryName">
                   <ItemTemplate>
                       <asp:Label ID="lblCountryName" runat="server" Text='<%# Eval("CountryName") %>'></asp:Label>
                   </ItemTemplate>
               </asp:TemplateField>
               <asp:TemplateField HeaderText="Action">
                   <ItemTemplate>
                       <table>
                           <tr>
                               <td>
                                   <asp:ImageButton ID="imgbtnEdit" runat="server" ImageUrl="~/Image/Edit.jpg"

                                       CommandName="Edit" ToolTip="Edit" Width="25px" />

                                   <asp:ImageButton ID="imgbtnDelete" runat="server" ImageUrl="~/Image/Delete.jpg"

                                       CommandName="Delete" ToolTip="Delete" Width="25px" /></td>
                           </tr>
                       </table>
                   </ItemTemplate>

               </asp:TemplateField>
           </Columns>
       </asp:GridView>
   </div>