问如何根据列类型过滤Gridview列

EN

<asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSource" 
        autogeneratecolumns="true"
        emptydatatext="No data available." 
        runat="server">

        <columns>
          <asp:boundfield datafield="CustomerID" headertext="Customer ID"/>
          <asp:boundfield datafield="CompanyName" headertext="Company Name"/>
          <asp:boundfield datafield="Address" headertext="Address"/>
          <asp:boundfield datafield="City" headertext="City"/>
          <asp:boundfield datafield="PostalCode" headertext="Postal Code"/>
          <asp:boundfield datafield="Country" headertext="Country"/>

      <asp:templatefield headertext="Author Name">
        <itemtemplate>
          <asp:label id="FirstNameLabel"
            Text= '<%# Eval("au_fname") %>'
            runat="server"/> 
          <asp:label id="LastNameLabel"
            Text= '<%# Eval("au_lname") %>'
            runat="server"/>
        </itemtemplate>
      </asp:templatefield>

      <asp:hyperlinkfield text="Details..."
        navigateurl="~\details.aspx"            
        headertext="Order Details"
        target="_blank" />
        </columns>

      </asp:gridview>