解决更新数据空值的问题，解决方案asp.net

<asp:DetailsView ID="DetailsView1" runat="server" AutoGenerateRows="False" DataKeyNames="ID"
DataSourceID="AccessDataSource1" DefaultMode="Edit" Height="50px" Width="422px"
OnItemUpdated="DetailsView1_ItemUpdated">
<Fields>
<asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False" ReadOnly="True"
SortExpression="ID" />
<asp:TemplateField HeaderText="标准院校名" SortExpression="标准院校名">
<EditItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Eval("标准院校名") %>'></asp:Label>

<asp:HiddenField ID="hwd" runat="server" Value='<%# Bind("标准院校名") %>' />
</EditItemTemplate>
<InsertItemTemplate>
<asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("标准院校名") %>'></asp:TextBox>

</InsertItemTemplate>
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Eval("标准院校名") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="专业名称" HeaderText="专业名称" SortExpression="专业名称" />
<asp:BoundField DataField="院校代码" HeaderText="院校代码" SortExpression="院校代码" />
<asp:BoundField DataField="专业代码" HeaderText="专业代码" SortExpression="专业代码" />
<asp:BoundField DataField="录取人数" HeaderText="录取人数" SortExpression="录取人数" />
<asp:BoundField DataField="分数" HeaderText="分数" SortExpression="分数" />
<asp:CommandField ShowEditButton="True" />
</Fields>
</asp:DetailsView>

 

protected void DetailsView1_ItemUpdated(object sender, DetailsViewUpdatedEventArgs e)
{
HiddenField hh = (HiddenField)DetailsView1.FindControl("hwd");
if (hh!=null)
{
e.NewValues["标准院校名"]=hh.Value;
}
}