将行添加到 ASP.NET GridView？

我有以下 GridView，其中有几个 DropDownLists 和 TextBoxes。如何在保留现有 GridView 的同时向其中添加新行。我想使用 LinkBut​​ton 添加新行。我没有使用 DataSource 控件，并且 GridView 当前是通过 DataTable 填充的。这是网格视图：

<asp:LinkButton ID="btnAdd" runat="server" Text="Add Room" 
        onclick="btnAdd_Click"></asp:LinkButton>
    <asp:GridView ID="gvRP" runat="server" AutoGenerateColumns="false" 
        onrowdatabound="gvRP_RowDataBound" 
        onrowediting="gvRP_RowEditing">
    <Columns>
    <asp:TemplateField HeaderText="Room" ItemStyle-Width="100%">
    <ItemTemplate>
    <asp:Label runat="server" Text="Room"></asp:Label>
    <asp:DropDownList ID="ddlRoom" runat="server" AutoPostBack="True" DataTextField="Name"
        DataValueField="Id" AppendDataBoundItems="true" OnSelectedIndexChanged="ddlRoom_SelectedIndexChanged">
        <asp:ListItem Value="-1">Select...</asp:ListItem>
    </asp:DropDownList>
    <asp:Label runat="server" AssociatedControlID="ddlRate" Text="Rate" ID="lblRate"></asp:Label><asp:DropDownList
        ID="ddlRate" runat="server" AppendDataBoundItems="true" DataTextField="Name"
        DataValueField="Id">
        <asp:ListItem Value="-1">Select...</asp:ListItem>
    </asp:DropDownList>

    <asp:Label  runat="server" Text="Adults"></asp:Label>
    <asp:TextBox ID="txtAdults" Text='<%#Bind("Adults") %>' runat="server" Width="25px"></asp:TextBox>
    <asp:Label  runat="server" Text="Children"></asp:Label>
    <asp:TextBox ID="txtChildren" Text='<%#Bind("Children") %>' runat="server"  Width="25px"></asp:TextBox>
    <asp:Label runat="server" Text="Check In"></asp:Label>
    <asp:TextBox ID="txtCheckIn" Text='<%#Bind("CheckIn") %>' runat="server" Width="75px"></asp:TextBox>
    <asp:Label  runat="server" Text="Check Out"></asp:Label>
    <asp:TextBox ID="txtCheckOut" Text='<%#Bind("CheckOut") %>' runat="server"  Width="75px"></asp:TextBox>

    <h3>Rates</h3>
    <asp:GridView ID="gvR" runat="server" AutoGenerateColumns="false">
    <Columns>
    <asp:BoundField DataField="Name" HeaderText="Rate" />
    <asp:BoundField DataField="Effective" HeaderText="Effective" />
    <asp:BoundField DataField="Expire" HeaderText="Expire" />
    <asp:BoundField DataField="Amount" HeaderText="Amount" />
    <asp:BoundField DataField="Code" HeaderText="Currency" />
    </Columns>
    </asp:GridView>
    </ItemTemplate>
    </asp:TemplateField>
    </Columns>
    </asp:GridView>

通常我会尝试做一个例子，但是这个例子非常彻底，而且我不“认为”该网址会去任何地方。请参阅这个链接 http://www.aspsnippets.com/Articles/Adding-Dynamic-Rows-in-ASP.Net-GridView-Control-with-TextBoxes.aspx一个全面的例子。

这是重要的代码。

grid

<FooterStyle HorizontalAlign="Right" />
<FooterTemplate>
    <asp:Button ID="ButtonAdd" runat="server" Text="Add New Row" />
</FooterTemplate>

代码隐藏

protected void ButtonAdd_Click(object sender, EventArgs e)
{
      AddNewRowToGrid()
}

private void AddNewRowToGrid()
{
    int rowIndex = 0;

    if (ViewState["CurrentTable"] != null)
    {
        DataTable dtCurrentTable = (DataTable)ViewState["CurrentTable"];
        DataRow drCurrentRow = null;
        if (dtCurrentTable.Rows.Count > 0)
        {
            for (int i = 1; i <= dtCurrentTable.Rows.Count; i++)
            {
                //extract the TextBox values
            }
            dtCurrentTable.Rows.Add(drCurrentRow);
            ViewState["CurrentTable"] = dtCurrentTable;

            Gridview1.DataSource = dtCurrentTable;
            Gridview1.DataBind();
        }
    }
    else
    {
        Response.Write("ViewState is null");
    }

    //Set Previous Data on Postbacks
    SetPreviousData();
}