'功能：将asp.net中DataGrid生成Excel文件下载。
'Mountains改进：1、支持中文 2、隐藏列不显示
'日期：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") '解决中文乱码之关键
'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) '必要，做成下载文件

Dim colHeaders As String = ""
Dim strItems As StringBuilder = New StringBuilder()

Dim myCol As DataGridColumn

Dim i As Integer

For i = 0 To colCount
myCol = MyDataGrid.Columns(i)
If myCol.Visible = True Then
colHeaders = colHeaders & myCol.HeaderText.ToString & ","
End If
Next

If colHeaders.Length > 0 Then
colHeaders = colHeaders.Substring(0, colHeaders.LastIndexOf(","))
End If

colHeaders = colHeaders & Chr(13) & Chr(10)

resp.Write(colHeaders)

Dim colRow As String

Dim item As DataGridItem

For Each item In MyDataGrid.Items
resp.Write(FormatExportRow(colCount, item, MyDataGrid))
Next item

resp.End()

End Function

Private Function FormatExportRow(ByVal colCount As Integer, ByVal Item As DataGridItem, ByVal MyDataGrid As System.Web.UI.WebControls.DataGrid) As String
Dim strItem As String
Dim i As Integer

For i = 0 To colCount
If MyDataGrid.Columns(i).Visible = True Then
If Item.Cells(i).Text Is System.DBNull.Value Then
Item.Cells(i).Text = ""
End If
If i = colCount Then
strItem += Item.Cells(i).Text.ToString & Chr(13) & Chr(10)
Else
strItem += Item.Cells(i).Text.ToString & ","
End If
End If
Next
strItem = Replace(strItem, " ", " ")
Return strItem
End Function

End Class

End Namespace