C# と VB.NET の質問掲示板

VBScriptでADBDB.Streamを使って「一行ずつ」と「残り一括」を比較したら、雲泥の差でしたよ。


Option Explicit
'On Error Resume Next

Const adTypeText = 2
Const adCRLF = -1
Const adLF = 10
Const adCR = 13
Const adReadAll = -1
Const adReadLine = -2
Const adWriteLine = 1 

Const adSaveCreateNotExist = 1
Const adSaveCreateOverWrite = 2

dim i, istream, ostream, s

s = Now()

Set istream = WScript.CreateObject("ADODB.Stream")
Set ostream = WScript.CreateObject("ADODB.Stream")
With ostream
  .Type = adTypeText
  .Charset = "shift-jis"
  .LineSeparator = adCRLF
  .Open
End With

With istream
  .Type = adTypeText
  .Charset = "shift-jis"
  .LineSeparator = adCRLF
  .Open
  .LoadFromFile "C:\temp\input.csv"
  For i = 1 to 1000
    .SkipLine
  Next


' Do While not .EOS
'   ostream.WriteText .ReadText(adReadLine), adWriteLine
' Loop
'↑↓どちらかを有効にして速度を計ってください
' .CopyTo ostream
  .Close
End With

ostream.SaveToFile  "C:\temp\output.csv", adSaveCreateOverWrite
ostream.Close

Set istream = Nothing
Set ostream = Nothing

Msgbox FormatDateTime(Now() - s)