I have a GridView that get the data from the table in DB,

CREATE TABLE [dbo].[EDU_Room](
	[Id] [tinyint] NOT NULL,
	[Title] [nvarchar](50) NOT NULL,
	[Floor] [tinyint] NULL,
	[Capacity] [tinyint] NOT NULL,
	[TypeId] [tinyint] NOT NULL)

<asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False" BackColor="White"
    BorderColor="#CCCCCC" BorderStyle="None" BorderWidth="1px" CellPadding="3" Width="49%"
    DataKeyNames="Id" CssClass="Hedear-center" HorizontalAlign="Center"
    Font-Names="Tahoma" Font-Size="Smaller" Style="margin-right: 0px" DataSourceID="EditCourseDB">
    <Columns>
        <asp:BoundField DataField="Id" HeaderText="Id" SortExpression="Id"
            HeaderStyle-CssClass="Hedear-center" ReadOnly="True">
        </asp:BoundField>
        <asp:BoundField DataField="Title" HeaderText="Title" SortExpression="Title"
            HeaderStyle-CssClass="Hedear-center">
        </asp:BoundField>
        <asp:BoundField DataField="Floor" HeaderText="Floor" SortExpression="Floor"
            HeaderStyle-CssClass="Hedear-center">
        </asp:BoundField>
        <asp:BoundField DataField="Capacity" HeaderText="Capacity" SortExpression="Capacity" HeaderStyle-CssClass="Hedear-center">
        </asp:BoundField>
        <asp:BoundField DataField="TypeId" HeaderText="TypeId" SortExpression="TypeId" HeaderStyle-CssClass="Hedear-center">
        </asp:BoundField>
    </Columns>
    <EmptyDataTemplate>
        <span class="auto-style14"><strong>هیچ واحد درسی تعریف نشده است</strong></span>
    </EmptyDataTemplate>
    <FooterStyle BackColor="White" ForeColor="#000066" />
    <HeaderStyle BackColor="#006699" Font-Bold="True" ForeColor="White" />
    <PagerStyle BackColor="White" ForeColor="#000066" HorizontalAlign="Left" />
    <RowStyle ForeColor="#000066" />
    <SelectedRowStyle BackColor="#669999" Font-Bold="True" ForeColor="White" />
    <SortedAscendingCellStyle BackColor="#F1F1F1" />
    <SortedAscendingHeaderStyle BackColor="#007DBB" />
    <SortedDescendingCellStyle BackColor="#CAC9C9" />
    <SortedDescendingHeaderStyle BackColor="#00547E" />
</asp:GridView>

<asp:SqlDataSource ID="EditCourseDB" runat="server" ConnectionString="<%$ ConnectionStrings:KDUIS-v1ConnectionString %>"
    SelectCommand="SELECT * FROM [EDU_Room]">
</asp:SqlDataSource>

now I don't want to show the Id field in GridView to the user. but I want to get the value of Id when I select each of row.

I can get the value of GridView white this code:

LblId.Text = row.Cells[0].Text;

and I set the:

Visible="false"

To hide the Id field. but when I set this property to false, I can't get the amount of Id field.

how can I do this?!