Privet!!!
Rebyata est problema , pozalusta pomogite.
Est datagrid v kotorom kucha dannih, kogda nazimayu na "Edit" otkrivaetsa okno gde vizu polnostyu vse dannie i mogu ih redaktirovat. Textovie polya vizu s dannimi a vot dropdownlists vizu no oni pustie.

eto v .aspx file
<edititemtemplate>
<b>City</b><br>
<asp:dropdownlist id="city" width="80" runat="server" cssclass="ib" datatextfield="cityname" datavaluefield="cityid" AutoPostBack="True" />
</edititemtemplate>


a vot zdes pitayus zapolnit dannimi

private void ItemDataBound(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
if(e.Item.ItemType == ListItemType.EditItem)
{
DropDownList listcity = ((DropDownList) e.Item.FindControl("city"));
Components.General city = new Components.General();
listcity.DataSource = city.AssetTypeGetList();
listcity.DataBind();
listcity.Items.Add(new ListItem(" ","0"));
}

if(e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{

}
}

poluchayu error :

System.NullReferenceException: Object reference not set to an instance of an object

Pomogite please srochno nado.

Vot source file .aspx

<asp:panel id="DataPanel" runat="server" visible="false">
<asp:datagrid id="dgItems" runat="server" allowpaging="false" datakeyfield="id" pagesize="5" autogeneratecolumns="False" width="750px">
<edititemstyle cssclass="adm_si"></edititemstyle>
<itemstyle cssclass="adm_tt"></itemstyle>
<headerstyle cssclass="adm_th"></headerstyle>
<Columns>
<asp:templatecolumn headertext="ID">
<headerstyle horizontalalign="Center" width="45px"></headerstyle>
<itemstyle verticalalign="Top"></itemstyle>
<itemtemplate>
<asp:Label runat="server" Text='<%# DataBinder.Eval(Container, "DataItem.id") %>' ID="lblID" />
</itemtemplate>
<edititemtemplate>
<%# DataBinder.Eval(Container, "DataItem.id") %>
<asp:textbox visible = false runat="server" text='<%# DataBinder.Eval(Container, "DataItem.id") %>' id="id"/>
</edititemtemplate>
</asp:templatecolumn>
<asp:templatecolumn headertext="City">
<headerstyle horizontalalign="Center"></headerstyle>
<itemstyle verticalalign="Top"></itemstyle>
<itemtemplate>
<asp:label runat="server" text='<%# DataBinder.Eval(Container, "DataItem.asset_city_name") %>' ID="lblCity">
</asp:label>
</itemtemplate>
<edititemtemplate>
<b>City</b><br>
<asp:dropdownlist id="city" width="80" runat="server" cssclass="ib" datatextfield="cityname" datavaluefield="cityid" />
</edititemtemplate>
</asp:templatecolumn>
</Columns>
<pagerstyle cssclass="nb" position="TopAndBottom" mode="NumericPages"></pagerstyle></asp:datagrid></asp:panel>

a v aspx.cs file ya vse opredelayu , tak vot kogda data grid v sostoyanii edit poyavlayutsa dopolnitelnie polya i dropdownlists kotorie dolzni imet dannie i tam mozno vse menat i delat Update , vse horosho rabotaet no dropdownlists ne zapolnayutsa dannimi , smotrel primeri drugih , vrode takze vse delayu a est error :( , please pomogite , esli nado eshe dannie skazite, poshlu. Spasibo

Mojet kto to dast primer kak eto sdelat.
Spasibo