The problem is solved and the improved code is posted first. (Implement to pour the data in the DataGrid out of the Excel file and download it)

Imports System
Imports System.Text
Namespace Toexcel
' Function: The datagrid in the ASP.net to generate Excel file downloads.
' Mountains improvement: 1, Support Chinese 2, hidden column does not show
' Date: 2002.10.30
Public Class Datagridtocsv
Public Function Generatefile (ByRef Page as System.Web.UI.Page, ByVal Mydatagrid as System.Web.UI.WebControls.DataGrid, ByVal FileName As String) as String
Dim resp as HttpResponse
Dim ColCount as Integer = mydatagrid.columns.count-1
RESP = Page.Response
Resp. ContentEncoding = System.Text.Encoding.GetEncoding ("GB2312") ' The key to solve Chinese garbled characters
' Resp. Charset = "Utf-8"
' Resp. AddFileDependency (FileName)
' Resp. ContentType = "Text/html"
"Resp." Appendheader ("Content-type", "text/html; charset=gb2312 ")
Resp. Appendheader ("Content-disposition", "attachment;filename=" + filename) ' necessary, made download file

Dim colheaders as String = ""