asp.net - 获取隐藏字段值

Question

我有一个 GridView 定义如下:

<asp:GridView ID="myGridView" AutoGenerateColumns="false" runat="server"
OnLoad="myGridView_Load" OnRowCommand="myGridView_Command" OnRowEditing="myGridView_RowEditing" OnRowDeleting="myGridView_RowDeleting" DataKeyNames="ID" > 
  <Columns>
    <asp:BoundField DataField="ID" Visible="false" />
    <asp:BoundField DataField="BirthDate" Visible="false" />
    <asp:BoundField DataField="FirstName" HeaderText="First Name" />
    <asp:BoundField DataField="LastName" HeaderText="Last Name" />
    <asp:TemplateField HeaderText="Other">
      <ItemTemplate>
        <asp:LinkButton ID="editLB" runat="server" Text="edit" CommandName="Edit" />
        <asp:LinkButton ID="deleteLB" runat="server" Text="delete" CommandName="Delete" />
      </ItemTemplate>
    </asp:TemplateField>
  </Columns>   
</asp:GridView>

当用户单击编辑按钮时，我需要获取 BirthDate 列的值。为了尝试这个，我尝试了以下方法:

protected void myGridView_RowEditing(object sender, GridViewEditEventArgs e)
{
  GridViewRow row = gvUsers.Rows[e.NewEditIndex];
  DateTime birthDate = (DateTime)(row.Cells[1].Text);

  // Does not work
}

我知道这与该列不可见有关。该列必须隐藏。但我需要获得该值 - 我该如何做到这一点？

Answer 1

问题在于，当 BoundField 的 Visibility 属性设置为 false 时，该列不会呈现给客户端。解决方法是在 TemplateField 中使用 HiddenField。

<asp:TemplateField>
    <ItemTemplate>
        <asp:HiddenField ID="HiddenField1" runat="server" 
                         Value='<%# Eval("BirthDate") %>' />
    </ItemTemplate>
    <EditItemTemplate>
        <asp:HiddenField ID="HiddenField1" runat="server" 
                         Value='<%# Eval("BirthDate") %>' />
    </EditItemTemplate>
</asp:TemplateField>

protected void GridView_RowEditing(object sender, GridViewEditEventArgs e)
{
    GridViewRow row = GridView.Rows[e.NewEditIndex];     
    HiddenField  hidden = (HiddenField)row.Cells[0].FindControl("HiddenField1");
    DateTime birthDate = Convert.ToDateTime(hidden.Value);
}

编辑

上述方法仍然会呈现表中的列，因此最终会得到一个空列。它有效，但不是最好的解决方案，这是隐藏 BirthDate 字段但仍然在 RowEditing 事件处理程序中获取其值的方法。请记住，生日仍然呈现给客户端，只是不显示。

<style type="text/css">
    .hide
    {
        display:none;
    }
</style>

<asp:BoundField DataField="BirthDate">
    <ItemStyle CssClass="hide"/>
</asp:BoundField>

protected void GridView_RowEditing(object sender, GridViewEditEventArgs e)
{
    GridViewRow row = GridView1.Rows[e.NewEditIndex];
    DateTime birthDate = Convert.ToDateTime(row.Cells[1].Text);
}