それはそれがどのように機能するかではありません。そのようにすると、ファイルはSQLサーバーに保存されます。
あなたがする必要があります
select * from your_table
データテーブルに。次に、FileHelpers ライブラリを使用して csv ファイルを作成します。
FileHelpers.CsvEngine.DataTableToCsv(dataTable, filename);
次に、この csv ファイルを HttpContext.Response に書き込み、添付ヘッダーを設定します。
Public Class TextHandler
Implements System.Web.IHttpHandler
Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
'context.Response.ContentType = "text/plain"
'context.Response.Write("Hello World!")
Dim memoryStream As New System.IO.MemoryStream()
Dim textWriter As System.IO.TextWriter = New System.IO.StreamWriter(memoryStream)
textWriter.WriteLine("YOUR CSV CONTENT")
textWriter.Flush()
memoryStream.Position = 0
Dim bytesInStream As Byte() = New Byte(memoryStream.Length - 1) {}
'memoryStream.Write(bytesInStream, 0, bytesInStream.Length)
memoryStream.Read(bytesInStream, 0, CInt(memoryStream.Length))
memoryStream.Close()
context.Response.Clear()
context.Response.ContentType = "application/octet-stream"
context.Response.AddHeader("Content-Disposition", GetContentDisposition(strFileName))
context.Response.BinaryWrite(bytesInStream)
context.Response.End()
End Sub
ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
Get
Return False
End Get
End Property
End Class
Public Shared Function StripInvalidPathChars(str As String) As String
If str Is Nothing Then
Return Nothing
End If
Dim strReturnValue As String = ""
Dim strInvalidPathChars As New String(System.IO.Path.GetInvalidPathChars())
Dim bIsValid As Boolean = True
For Each cThisChar As Char In str
bIsValid = True
For Each cInvalid As Char In strInvalidPathChars
If cThisChar = cInvalid Then
bIsValid = False
Exit For
End If
Next cInvalid
If bIsValid Then
strReturnValue += cThisChar
End If
Next cThisChar
Return strReturnValue
End Function ' StripInvalidPathChars
Public Shared Function GetContentDisposition(ByVal strFileName As String) As String
' http://stackoverflow.com/questions/93551/how-to-encode-the-filename-parameter-of-content-disposition-header-in-http
Dim contentDisposition As String
strFileName = StripInvalidPathChars(strFileName)
If System.Web.HttpContext.Current IsNot Nothing AndAlso System.Web.HttpContext.Current.Request.Browser IsNot Nothing Then
If (System.Web.HttpContext.Current.Request.Browser.Browser = "IE" And (System.Web.HttpContext.Current.Request.Browser.Version = "7.0" Or System.Web.HttpContext.Current.Request.Browser.Version = "8.0")) Then
contentDisposition = "attachment; filename=" + Uri.EscapeDataString(strFileName).Replace("'", Uri.HexEscape("'"c))
ElseIf (System.Web.HttpContext.Current.Request.Browser.Browser = "Safari") Then
contentDisposition = "attachment; filename=" + strFileName
Else
contentDisposition = "attachment; filename*=UTF-8''" + Uri.EscapeDataString(strFileName)
End If
Else
contentDisposition = "attachment; filename*=UTF-8''" + Uri.EscapeDataString(strFileName)
End If
Return contentDisposition
End Function ' GetContentDisposition
CSV はプレーン テキストであるため、MemoryStream を使用せずに、ContentType を設定し、Attach + テキストを Response に直接書き込むことができます。