ASP.NET GridView 默认排序顺序

我有一个绑定到 sql 数据源的简单 gridview 控件。现在我启用了排序，但是当我单击要排序的列时，它首先按升序对其进行排序。当我再次单击同一列时，它会按降序排序。我想改变这一点。我希望它在第一次单击时按降序排序，在第二次单击时按升序排序。我怎么做？

这是我的 Gridview 控件代码：

<asp:GridView ID="GridView1" runat="server" AllowSorting="True" 
        AutoGenerateColumns="False" BackColor="White" BorderColor="#999999" 
        BorderStyle="Solid" BorderWidth="1px" CellPadding="3" 
        DataSourceID="SqlDataSource1" ForeColor="Black" GridLines="Vertical" >
        <AlternatingRowStyle BackColor="#CCCCCC" />
        <Columns>
            <asp:BoundField DataField="Name" HeaderText="Name" />
            <asp:BoundField DataField="Team" HeaderText="Team" SortExpression="Team" />
            <asp:BoundField DataField="Matches" HeaderText="Matches" 
                SortExpression="Matches" />
            <asp:BoundField DataField="Points" HeaderText="Points" 
                SortExpression="Points" />
            <asp:BoundField DataField="Tries" HeaderText="Tries" SortExpression="Tries" />
            <asp:BoundField DataField="Conversions" HeaderText="Conversions" 
                SortExpression="Conversions"  />
            <asp:BoundField DataField="Penalties" HeaderText="Penalties" 
                SortExpression="Penalties" />
            <asp:BoundField DataField="Drop Goals" HeaderText="Drop Goals" 
                SortExpression="Drop Goals" />
            <asp:BoundField DataField="Yellow Cards" HeaderText="Yellow Cards" 
                SortExpression="Yellow Cards" />
            <asp:BoundField DataField="Red Cards" HeaderText="Red Cards" 
                SortExpression="Red Cards" />
        </Columns>
        <FooterStyle BackColor="#CCCCCC" />
        <HeaderStyle BackColor="Black" Font-Bold="True" ForeColor="White" />
        <PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />
        <SelectedRowStyle BackColor="#000099" Font-Bold="True" ForeColor="White" />
        <SortedAscendingCellStyle BackColor="#F1F1F1" />
        <SortedAscendingHeaderStyle BackColor="#808080" />
        <SortedDescendingCellStyle BackColor="#CAC9C9" />
        <SortedDescendingHeaderStyle BackColor="#383838" />
    </asp:GridView>
    <asp:SqlDataSource ID="SqlDataSource1" runat="server" 
        ConnectionString="<%$ ConnectionStrings:ConnectionString %>" 
        SelectCommand="SELECT * FROM [statstable]"></asp:SqlDataSource> 

public partial class _Default : Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        // Set your deault sort expression and direction.
        if (String.IsNullOrEmpty(MyGridView.SortExpression)) MyGridView.Sort("SortExpression", SortDirection.Ascending);
    }
}