我无法绑定(bind)edititem模板中的下拉列表。当我尝试访问它时得到空引用。我的设计:'runat="server"/>我的代码背后:protectedvoidgv_RowEditing(objectsender,GridViewEditEventArgse){gv_table1.EditIndex=e.NewEditIndex;DropDownListdrpcategory1=((DropDownList)gv_table1.Rows[e.NewEditIndex].Cells[8].FindControl("drpcategory1"));//BindDropDown(dr