可以尝试以下代码

protected void Button1_Click(object sender, EventArgs e)
   {
       DataTable dt = new DataTable();

       if (dt.Columns.Count == 0)
       {
           dt.Columns.Add("PayScale", typeof(string));
           dt.Columns.Add("IncrementAmt", typeof(string));
           dt.Columns.Add("Period", typeof(string));
       }

       DataRow NewRow = dt.NewRow();
       NewRow[0] = TextBox1.Text;
       NewRow[1] = TextBox2.Text;
       dt.Rows.Add(NewRow); 
       GridView1.DataSource = dt;
       GridViewl.DataBind();
   }

这里PayScale、Incrementamt和Period是数据库字段名。

您可以直接运行此示例。
aspx页面：

<asp:GridView ID="grd" runat="server" DataKeyNames="PayScale" AutoGenerateColumns="false">
    <Columns>
        <asp:TemplateField HeaderStyle-HorizontalAlign="Left" HeaderText="Pay Scale">
            <ItemTemplate>
                <asp:TextBox ID="txtPayScale" runat="server" Text='<%# Eval("PayScale") %>'></asp:TextBox>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderStyle-HorizontalAlign="Left" HeaderText="Increment Amount">
            <ItemTemplate>
                <asp:TextBox ID="txtIncrementAmount" runat="server" Text='<%# Eval("IncrementAmount") %>'></asp:TextBox>
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField HeaderStyle-HorizontalAlign="Left" HeaderText="Period">
            <ItemTemplate>
                <asp:TextBox ID="txtPeriod" runat="server" Text='<%# Eval("Period") %>'></asp:TextBox>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>
<asp:Button ID="btnAddRow" runat="server" OnClick="btnAddRow_Click" Text="Add Row" />

C#代码：

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        grd.DataSource = GetTableWithInitialData(); // get first initial data
        grd.DataBind();
    }
}

public DataTable GetTableWithInitialData() // this might be your sp for select
{
    DataTable table = new DataTable();
    table.Columns.Add("PayScale", typeof(string));
    table.Columns.Add("IncrementAmount", typeof(string));
    table.Columns.Add("Period", typeof(string));

    table.Rows.Add(1, "David", "1");
    table.Rows.Add(2, "Sam", "2");
    table.Rows.Add(3, "Christoff", "1.5");
    return table;
}

protected void btnAddRow_Click(object sender, EventArgs e)
{
    DataTable dt = GetTableWithNoData(); // get select column header only records not required
    DataRow dr;

    foreach (GridViewRow gvr in grd.Rows)
    {
        dr = dt.NewRow();

        TextBox txtPayScale = gvr.FindControl("txtPayScale") as TextBox;
        TextBox txtIncrementAmount = gvr.FindControl("txtIncrementAmount") as TextBox;
        TextBox txtPeriod = gvr.FindControl("txtPeriod") as TextBox;

        dr[0] = txtPayScale.Text;
        dr[1] = txtIncrementAmount.Text;
        dr[2] = txtPeriod.Text;

        dt.Rows.Add(dr); // add grid values in to row and add row to the blank table
    }

    dr = dt.NewRow(); // add last empty row
    dt.Rows.Add(dr);

    grd.DataSource = dt; // bind new datatable to grid
    grd.DataBind();
}

public DataTable GetTableWithNoData() // returns only structure if the select columns
{
    DataTable table = new DataTable();
    table.Columns.Add("PayScale", typeof(string));
    table.Columns.Add("IncrementAmount", typeof(string));
    table.Columns.Add("Period", typeof(string));
    return table;
}

protected void TableGrid_RowDataBound(object sender, GridViewRowEventArgs e)
{
   if (e.Row.RowIndex == -1 && e.Row.RowType == DataControlRowType.Header)
   {
      GridViewRow gvRow = new GridViewRow(0, 0, DataControlRowType.DataRow,DataControlRowState.Insert);
      for (int i = 0; i < e.Row.Cells.Count; i++)
      {
         TableCell tCell = new TableCell();
         tCell.Text = "&nbsp;";
         gvRow.Cells.Add(tCell);
         Table tbl = e.Row.Parent as Table;
         tbl.Rows.Add(gvRow);
      }
   }
}

尝试使用克隆技术。

{
    DataGridViewRow row = (DataGridViewRow)yourdatagrid.Rows[0].Clone();
    // then for each of the values use a loop like below.
    int cc = yourdatagrid.Columns.Count;
    for (int i2 = 0; i < cc; i2++)
    {
        row.Cells[i].Value = yourdatagrid.Rows[0].Cells[i].Value;
    }
    yourdatagrid.Rows.Add(row);
    i++;
    }
}

这个应该可以用。不过我不确定绑定是如何工作的。希望它不会阻止这个工作。

如果使用数据集在网格中绑定，则可以在填写sql数据适配器后添加行：

adapter.Fill(ds);
ds.Tables(0).Rows.Add();