自定义gridview某列的数据(初学者)

 <asp:templatefield HeaderText="库存数量">
                    <itemtemplate>
                        <asp:Label ID="Label1" runat="server" 
                            Text='<%# (int)Eval("total_number") - (int)Eval("lead_number") %>'></asp:Label>
                    </itemtemplate>
                </asp:templatefield>