GridView 輸出成Excel

    Protected Sub bt_excel_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles bt_excel.Click
        Response.Clear()

        Response.AddHeader("content-disposition", "attachment;filename=Export.xls")
        Response.ContentType = "application/vnd.ms-excel"
        Dim sw As New System.IO.StringWriter()
        Dim htw As New HtmlTextWriter(sw)
        GridView1.HeaderStyle.BackColor = Color.White
        GridView1.HeaderStyle.ForeColor = Color.Black
        GridView1.AlternatingRowStyle.BackColor = Color.White
        GridView1.RowStyle.BackColor = Color.White
        '關閉換頁跟排序
        'GridView1.AllowSorting = false;
        'GridView1.AllowPaging = false;

        '//移去不要的欄位
        'GridView1.Columns.RemoveAt(GridView1.Columns.Count - 1);
        'GridView1.DataBind();

        '//建立假HtmlForm避免以下錯誤
        '//Control 'GridView1' of type 'GridView' must be placed inside
        '//a form tag with runat=server.
        '//另一種做法是override VerifyRenderingInServerForm後不做任何事
        '//這樣就可以直接GridView1.RenderControl(htw);
        Response.Write("<meta http-equiv=Content-Type content=text/html;charset=utf-8>")
        GridView1.RenderControl(htw)
        'Dim hf As New HtmlForm()
        'Controls.Add(hf)
        'hf.Controls.Add(GridView1)
        'hf.RenderControl(htw)

        Response.Write(sw.ToString())
        Response.End()
    End Sub