GridView绑定DropdownList
我现在做的是在页面加载的时候，就绑定DropdownList，然后也可以更新，可是我想要的效果是加载的时候，显示的是一个label，点编辑的时候这列才显示DropdownList,我现在这个如果显示的时候是label就出错。请问怎么做，我的代码如下：
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HTML
<asp:GridView   ID= "GridView1 "   runat= "server "   OnRowCancelingEdit= "GridView1_RowCancelingEdit "   OnRowUpdating "GridView1_RowUpdating "   OnRowEditing= "GridView1_RowEditing "   AutoGenerateColumns= "False "   DataKeyNames= "EpId "   OnRowDataBound= "GridView1_RowDataBound ">
    <Columns>
        <asp:TemplateField   HeaderText= "所属大类 "   SortExpression= "goodsType ">
            <EditItemTemplate>
          <asp:DropDownList   ID= "DropDownList1 "runat= "server "> </asp:DropDownList>
            </EditItemTemplate>
            <ItemTemplate>
              <asp:DropDownList   ID= "DropDownList1 "     runat= "server "/>
              </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField   HeaderText= "操作 "   ShowHeader= "False ">
        <EditItemTemplate>
          <asp:LinkButton   ID= "LinkButton1 "   runat= "server "   CausesValidation= "True "   CommandName= "Update "Text= "更新 "> </asp:LinkButton>
            <asp:LinkButton   ID= "LinkButton2 "   runat= "server "   CausesValidation= "False "   CommandName= "Cancel "
            Text= "取消 "> </asp:LinkButton>
              </EditItemTemplate>
              <ItemTemplate>
              <asp:LinkButton   ID= "LinkButton1 "   runat= "server "   CausesValidation= "False "   CommandName= "Edit "Text= "编辑 "> </asp:LinkButton>
              </ItemTemplate>
              </asp:TemplateField>
              </Columns>
            </asp:GridView>
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CS代码中：
protected   void   GridView1_RowDataBound(object   sender,   GridViewRowEventArgs   e)
        {

                if   (e.Row.RowType   ==   DataControlRowType.DataRow)
                {
                        DropDownList   goodsType   =   (DropDownList)e.Row.FindControl( "DropDownList1 ");
                        con   =   new   SqlConnection(ConfigurationManager.ConnectionStrin