GridView
<asp:GridView ID="GridView1" runat="server">
<Columns>
<asp:TemplateField HeaderText="Number">
<ItemTemplate>
<%# Container.DataItemIndex + 1 %>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
Repeater
<asp:Repeater ID="Repeater1" runat="server">
<ItemTemplate>
<asp:Label ID="lblIndex" runat="server" Text='<%# Container.ItemIndex + 1 %>' />
</ItemTemplate>
</asp:Repeater>
DataList
<asp:DataList runat="server" ID="DataList1">
<ItemTemplate>
<asp:Label ID="lblIndex" runat="server" Text='<%# Container.ItemIndex + 1 %>' />
</ItemTemplate>
</asp:DataList>
FormView
<asp:FormView ID="FormView1" runat="server">
<ItemTemplate>
<asp:Label ID="lblIndex" runat="server" Text='<%# Container.DataItemIndex + 1 %>' />
</ItemTemplate>
</asp:FormView>
DetailsView
<asp:DetailsView ID="DetailsView1" runat="server">
<Fields>
<asp:TemplateField>
<ItemTemplate>
<asp:Label ID="lblIndex" runat="server" Text='<%# Container.DataItemIndex + 1 %>' />
</ItemTemplate>
</asp:TemplateField>
</Fields>
</asp:DetailsView>