数据库中有的字段为null时，反馈到页面上是什么也不显示？如何用一个【无】字来代替呢？

<asp:ListView ID="listViewCustomer" DataSourceID="ods_Customer" runat="server" 
        DataKeyNames="CustomerId">        
        <EditItemTemplate>
            <tr style="">
                <td>
                    <asp:TextBox ID="FNameTextBox" runat="server" Text='<%# Bind("FName") %>' />
                </td>
                <td>
                    <asp:TextBox ID="FAddressTextBox" runat="server" 
                        Text='<%# Bind("FAddress") %>' />
                </td>
                <td>
                    <asp:TextBox ID="FTelTextBox" runat="server" Text='<%# Bind("FTel") %>' />
                </td>
                <td>
                    <asp:TextBox ID="FFaxTextBox" runat="server" Text='<%# Bind("FFax") %>' />
                </td>
                <td>
                    <asp:Button ID="UpdateButton" runat="server" CommandName="Update" Text="更新" />
                    <asp:Button ID="CancelButton" runat="server" CommandName="Cancel" Text="取消" />
                </td>
            </tr>
        </EditItemTemplate>
        <EmptyDataTemplate>
            <table runat="server" style="">
                <tr>
                    <td>
                        未返回数据。</td>
                </tr>
            </table>
        </EmptyDataTemplate>        
        <ItemTemplate>
            <tr style="">
                <td>                                        
                    <asp:Label ID="FNameLabel" runat="server" Text='<%# Eval("FName") %>' />
                </td>
                <td>                    
                    <asp:Label ID="FAddressLabel" runat="server" Text='<%# (Eval("FAddress").ToString() == string.Empty) ? "无" : Eval("FAddress") %>' />
                </td>
                <td>
                    <asp:Label ID="FTelLabel" runat="server" Text='<%# (Eval("FTel").ToString() == string.Empty) ? "无" : Eval("FTel") %>' />
                </td>
                <td>
                    <asp:Label ID="FFaxLabel" runat="server" Text='<%# Eval("FFax").ToString() == string.Empty ? "无" : Eval("FFax") %>' />
                </td>
                <td>
                    <asp:Button ID="DeleteButton" runat="server" CommandName="Delete" Text="删除" />
                    <asp:Button ID="EditButton" runat="server" CommandName="Edit" Text="编辑" />
                </td>
            </tr>
        </ItemTemplate>
        <LayoutTemplate>
            <table runat="server">
                <tr runat="server">
                    <td runat="server">
                        <table ID="itemPlaceholderContainer" runat="server" border="0" style="">
                            <tr runat="server" style="">
                                <th runat="server">
                                    FName</th>
                                <th runat="server">
                                    FAddress</th>
                                <th runat="server">
                                    FTel</th>
                                <th runat="server">
                                    FFax</th>
                                <th id="Th1" runat="server">
                                </th>
                            </tr>
                            <tr ID="itemPlaceholder" runat="server">
                            </tr>
                        </table>
                    </td>
                </tr>
                <tr runat="server">
                    <td runat="server" style="">
                        <asp:DataPager ID="DataPager1" runat="server">
                            <Fields>
                                <asp:NextPreviousPagerField ButtonType="Button" ShowFirstPageButton="True" 
                                    ShowLastPageButton="True" />
                            </Fields>
                        </asp:DataPager>
                    </td>
                </tr>
            </table>
        </LayoutTemplate>        
    </asp:ListView>

　　主要是看ItemTemplate部分，另外值得一提的是编辑模板不要改动，那样会正常的更新回数据库