asp.net - 更新查询似乎删除了备注字段

Question

好的，我有一个 Gridview 控件，用于编辑数据库中的记录。我也参数化了查询。代码如下:

<asp:GridView ID="GridView1" runat="server" AllowSorting="True" 
    AutoGenerateEditButton="true" AutoGenerateDeleteButton="true" 
    DataSourceID="AccessDataSource1"
    AutoGenerateColumns="False" DataKeyNames="ID"
    AlternatingRowStyle-BackColor="Gray"  
    AlternatingRowStyle-CssClass="editGridFormat" RowStyle-CssClass="editGridFormat"        
    RowStyle-VerticalAlign="Top" 
    onselectedindexchanged="GridView1_SelectedIndexChanged">

    <Columns>
        <asp:CommandField ShowSelectButton="True" />
        <asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False" 
            ReadOnly="True" SortExpression="ID" />
        <asp:BoundField DataField="BlogTitle" HeaderText="BlogTitle" 
            SortExpression="BlogTitle" />
        <asp:ImageField DataImageUrlField="Image" HeaderText="Image"
            DataImageUrlFormatString="~/PlaceImages/{0}" ControlStyle-CssClass="editPhotoGridFormat"
            AlternateText="Something went wrong" 
            NullDisplayText="No picture on file" />
        <asp:TemplateField headertext="PicText">
            <EditItemTemplate>
                <asp:TextBox id="PicTextBox" runat="server" text='<%# Eval("PicText")%>' textmode="MultiLine" height="300px" width="300px" />
            </EditItemTemplate>
            <ItemTemplate>
                <%# Eval("PicText")%>
            </ItemTemplate>
        </asp:TemplateField>

        <asp:BoundField DataField="TravelDate" HeaderText="TravelDate" SortExpression="TravelDate" />
        <asp:TemplateField headertext="BeginText">
            <EditItemTemplate>
                <asp:TextBox id="BeginTextBox" runat="server" text='<%# Eval("BeginText")%>' textmode="MultiLine" height="300px" width="300px" />
            </EditItemTemplate>
            <ItemTemplate>
                <%# Eval("BeginText")%>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:BoundField DataField="Caption" HeaderText="Caption" />
        <asp:BoundField DataField="City" HeaderText="City" />
        <asp:BoundField DataField="Country" HeaderText="Country" 
            SortExpression="Country" />
        <asp:TemplateField headertext="EndText">
            <EditItemTemplate>
                <asp:TextBox id="EndTextBox" runat="server" text='<%# Eval("EndText")%>' textmode="MultiLine" height="300px" width="300px" />
            </EditItemTemplate>
            <ItemTemplate>
                <%# Eval("EndText")%>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>

</asp:GridView>

<asp:AccessDataSource ID="AccessDataSource1" runat="server" 
    DataFile="~/App_Data/TravelJoansDB.mdb" 
    SelectCommand="SELECT * FROM [Table2]" 
    DeleteCommand="DELETE FROM Table2 WHERE [ID] = ?"
    UpdateCommand="UPDATE Table2 SET [BlogTitle] = ?, 
                                     [Image] = ?, 
                                     [PicText] = ?, 
                                     [TravelDate] = ?, 
                                     [BeginText] = ?, 
                                     [Caption] = ?, 
                                     [City] = ?, 
                                     [Country] = ?, 
                                     [EndText] = ? 
                                     WHERE [ID] = ? " >

    <DeleteParameters>
        <asp:Parameter Name="ID" Type="Int32" />
    </DeleteParameters>
    <UpdateParameters>
        <asp:Parameter Name="BlogTitle" Type="String" />
        <asp:Parameter Name="Image" Type="String" />
        <asp:Parameter Name="PicText" Type="String" />
        <asp:Parameter Name="TravelDate" DbType="Date" />
        <asp:Parameter Name="BeginText" Type="String" />
        <asp:Parameter Name="Caption" Type="String" />
        <asp:Parameter Name="City" Type="String" />
        <asp:Parameter Name="Country" Type="String" />
        <asp:Parameter Name="EndText" Type="String" />
    </UpdateParameters>
</asp:AccessDataSource>

不确定这是否与 TemplateField 控件或参数类型为字符串有关。我之所以提到 Type 属性，是因为在我的 Access 数据库中，它们是 memo 类型，但我能看到的唯一具有一半可比性的是 string 类型。我敢打赌字符串类型不够大，无法容纳备注字段，但我不知道还会发生什么。任何帮助将不胜感激。

Answer 1

备注字段没有任何问题。它是 edititemtemplatefields，您没有绑定(bind)数据。将 Eval 更改为 Bind，例如，更改如下:

<EditItemTemplate>
    <asp:TextBox id="PicTextBox" runat="server" text='<%# Eval("PicText")%>' textmode="MultiLine" height="300px" width="300px" />
</EditItemTemplate>

对此:

<EditItemTemplate>
    <asp:TextBox id="PicTextBox" runat="server" text='<%# Bind("PicText")%>' textmode="MultiLine" height="300px" width="300px" />
</EditItemTemplate>

更改此:

<EditItemTemplate>
    <asp:TextBox id="BeginTextBox" runat="server" text='<%# Eval("BeginText")%>' textmode="MultiLine" height="300px" width="300px" />
</EditItemTemplate>

对此:

<EditItemTemplate>
    <asp:TextBox id="BeginTextBox" runat="server" text='<%# Bind("BeginText")%>' textmode="MultiLine" height="300px" width="300px" />
</EditItemTemplate>

并更改此:

<EditItemTemplate>
    <asp:TextBox id="EndTextBox" runat="server" text='<%# Eval("EndText")%>' textmode="MultiLine" height="300px" width="300px" />
</EditItemTemplate>

对此:

<EditItemTemplate>
    <asp:TextBox id="EndTextBox" runat="server" text='<%# Bind("EndText")%>' textmode="MultiLine" height="300px" width="300px" />
</EditItemTemplate>

我已经使用access db对其进行了测试。希望对您有帮助!