how to set datasource for dropdownlist inside of the grid in asp.net

<asp:TemplateField>

<HeaderTemplate>

Client

</HeaderTemplate>

<ItemTemplate>

<asp:Panel ID="pnlClient" runat="server">

<asp:DropDownList ID="ddlClient" runat="server" DataTextField="Clientname" DataValueField="clientid"

DataSource='<%#GetDSfDDL(Eval("client"))%>' AutoPostBack="True" OnSelectedIndexChanged="ddlClient_SelectedIndexChanged">

</asp:DropDownList>

</asp:Panel>

<%-- <asp:Label ID="lblClient" runat="server" Text='<%# bind("Client")%>'></asp:Label>--%>

</ItemTemplate>

<EditItemTemplate>

</EditItemTemplate>

</asp:TemplateField>

public List<clientddl> GetDSfDDL(object client)

{

List<clientddl> values = new List<clientddl>();

string[] cl = client.ToString().Split('/');

　

dt = new DataTable();

dt = bussclass.fnclientlist();

for (int i = 0; i < dt.Rows.Count; i++)

{

clientddl value = new clientddl();

value.Clientid = getint(dt.Rows[i]["client_id"]);

value.Clientname = dt.Rows[i]["client_name"].ToString();

values.Add(value);

}

for (int i = 0; i < values.Count; i++)

{

clientddl temp = new clientddl();

if (values[i].Clientid == getint(cl[0]))

{

if (i > 0)

{

temp = values[0];

values[0] = values[i];

values[i] = temp;

}

}

}

　

return values;

}