Lightbox Info Board : SQLの窓

' ********************************************************
' ■ テキストファイルの処理
' ********************************************************
Imports System.IO
Imports System.Text

Module MyModule

' ********************************************************
' VB.net 内は Unicode ですから、それを中心に考えます
' 左側がファイルで、右側がメモリです
' ********************************************************
Sub Main()

	' ********************************************************
	' =============        =============
	' | SHIFT_JIS |   =>   |  UNICODE  |
	' =============        =============
	' ********************************************************
	Dim SJISFileIn As StreamReader = New StreamReader( "readme.txt", Encoding.GetEncoding(932) )
	' 全て読み込む
	Dim Text1 As String = SJISFileIn.ReadToEnd()
	' 閉じる
	SJISFileIn.Close()
	SJISFileIn.Dispose()


	' ********************************************************
	' =============        =============
	' | UTF8(BOM) |   <=   |  UNICODE  |
	' =============        =============
	' ********************************************************
	' BOM あり
	Dim UTF8BOM As UTF8Encoding = New UTF8Encoding(True)	' Encoding.UTF8 と同等
	' 第二引数 : False で上書き、True ならば追加
	Dim UTF8FileOut As StreamWriter = New StreamWriter( "readme_utf8.txt", False, UTF8BOM )
	UTF8FileOut.Write( Text1 )
	UTF8FileOut.Close()
	UTF8FileOut.Dispose()


	' ********************************************************
	' =============        =============
	' | UTF8(BOM) |   =>   |  UNICODE  |
	' =============        =============
	' ********************************************************
	Dim UTF8FileIn As StreamReader = New StreamReader( "readme_utf8.txt", UTF8BOM )
	' 全て読み込む
	Dim Text2 As String = UTF8FileIn.ReadToEnd()
	' 閉じる
	UTF8FileIn.Close()
	UTF8FileIn.Dispose()


	' ********************************************************
	' 内部表現の Unicode で 同じものとなります
	' ********************************************************
	if Text1 = Text2 then
		Console.WriteLine("SHIFT_JIS から読んだものと、UTF-8 から読んだものは同じです")
	end if


	' ********************************************************
	' UTF8N は 先頭に BOM がありません
	' UTF8Encoding のデフォルトの状態です
	' =============        =============
	' |   UTF8N   |   <=   |  UNICODE  |
	' =============        =============
	' ********************************************************
	' BOM なし
	Dim UTF8noBOM As UTF8Encoding = New UTF8Encoding()
	' 第二引数 : False で上書き、True ならば追加
	Dim UTF8NFileOut As StreamWriter = New StreamWriter( "readme_utf8n.txt", False, UTF8noBOM )
	UTF8NFileOut.Write( Text1 )
	UTF8NFileOut.Close()
	UTF8NFileOut.Dispose()


	' ********************************************************
	' =============        =============
	' |   UTF8N   |   =>   |  UNICODE  |
	' =============        =============
	' ********************************************************
	Dim UTF8NFileIn As StreamReader = New StreamReader( "readme_utf8n.txt", UTF8noBOM )
	' 全て読み込む
	Dim Text3 As String = UTF8NFileIn.ReadToEnd()
	' 閉じる
	UTF8NFileIn.Close()
	UTF8NFileIn.Dispose()

	' ********************************************************
	' 内部表現の Unicode で 同じものとなります
	' ********************************************************
	if Text2 = Text3 then
		Console.WriteLine("UTF8(BOM) から読んだものと、UTF8N から読んだものは同じです")
	end if


	' ********************************************************
	' =============        =============
	' |   EUC-JP  |   <=   |  UNICODE  |
	' =============        =============
	' ********************************************************
	Dim EUCJP As Encoding = Encoding.GetEncoding(51932)
	' 第二引数 : False で上書き、True ならば追加
	Dim EUCJPFileOut As StreamWriter = New StreamWriter( "readme_eucjp.txt", False, EUCJP )
	EUCJPFileOut.Write( Text3 )
	EUCJPFileOut.Close()
	EUCJPFileOut.Dispose()


	' ********************************************************
	' =============        =============
	' |  EUC-JP   |   =>   |  UNICODE  |
	' =============        =============
	' ********************************************************
	Dim EUCJPFileIn As StreamReader = New StreamReader( "readme_eucjp.txt", EUCJP )
	' 全て読み込む
	Dim Text4 As String = EUCJPFileIn.ReadToEnd()
	' 閉じる
	EUCJPFileIn.Close()
	EUCJPFileIn.Dispose()


	' ********************************************************
	' 内部表現の Unicode で 同じものとなります
	' ********************************************************
	if Text3 = Text4 then
		Console.WriteLine("UTF8N から読んだものと、EUC-JP から読んだものは同じです")
	end if


	' ********************************************************
	' =============        =============
	' |  UNICODE  |   <=   |  UNICODE  |
	' =============        =============
	' ********************************************************
	Dim UNICODE As Encoding = Encoding.Unicode 
	' 第二引数 : False で上書き、True ならば追加
	Dim UNICODEFileOut As StreamWriter = New StreamWriter( "readme_unicode.txt", False, UNICODE )
	UNICODEFileOut.Write( Text4 )
	UNICODEFileOut.Close()
	UNICODEFileOut.Dispose()


	' ********************************************************
	' =============        =============
	' |  UNICODE  |   =>   |  UNICODE  |
	' =============        =============
	' ********************************************************
	Dim UNICODEFileIn As StreamReader = New StreamReader( "readme_unicode.txt", UNICODE )
	' 全て読み込む
	Dim Text5 As String = UNICODEFileIn.ReadToEnd()
	' 閉じる
	UNICODEFileIn.Close()
	UNICODEFileIn.Dispose()


	' ********************************************************
	' 内部表現の Unicode で 同じものとなります
	' ********************************************************
	if Text4 = Text5 then
		Console.WriteLine("EUC-JPから読んだものと、UNICODE から読んだものは同じです")
	end if


	' ********************************************************
	' =============        =============
	' | SHIFT_JIS |   <=   |  UNICODE  |
	' =============        =============
	' ********************************************************
	Dim SHIFTJIS As Encoding = Encoding.GetEncoding(932)
	' 第二引数 : False で上書き、True ならば追加
	Dim SHIFTJISFileOut As StreamWriter = New StreamWriter( "readme_shiftjis.txt", False, SHIFTJIS )
	SHIFTJISFileOut.Write( Text5 )
	SHIFTJISFileOut.Close()
	SHIFTJISFileOut.Dispose()


	' ********************************************************
	' =============        =============        =============
	' | SHIFT_JIS |   =>   |   Byte()  |   =>   |  UNICODE  |
	' =============        =============        =============
	' ********************************************************
	Dim fs As FileStream = New FileStream( "readme_shiftjis.txt", FileMode.Open )
	Dim fb As Byte() = New Byte( fs.Length ){}
	fs.Read( fb, 0, fs.Length )
	' SHIFT_JIS で文字列化
	Dim Text6 As String = SHIFTJIS.GetString( fb, 0, fs.Length )
	fs.Close()
	fs.Dispose()

	' ********************************************************
	' 内部表現の Unicode で 同じものとなります
	' ********************************************************
	if Text5 = Text6 then
		Console.WriteLine("StreamReader から読んだものと、FileStream から読んだものは同じです")
	end if


	' ********************************************************
	' =============        =============        =============
	' |iso-2022-jp|   <=   |   Byte()  |   <=   |  UNICODE  |
	' =============        =============        =============
	' ********************************************************
	fb = Encoding.GetEncoding(50222).GetBytes(Text6)
	Dim fso As FileStream = New FileStream( "readme_jis.txt", FileMode.Create )
	fso.Write( fb, 0, fb.Length )
	fso.Close()
	fso.Dispose()


	' ********************************************************
	' 改行コードで分解する
	' 
	' 1) Windows では、CrLf なので、Cr を削除しておく
	' 2) Lf で分割する
	' ********************************************************
	Dim ByteCr As Byte() = New Byte() { 13 }
	Dim ByteLf As Byte() = New Byte() { 10 }

	' 文字列としての Cr
	Dim repl As String = Encoding.ASCII.GetString(ByteCr)

	' 置換前のテキストの量
	Console.WriteLine( Text5.Length )
	' 置換
	Text5 = Text5.Replace( repl,"" )
	' 置換後のテキストの量
	Console.WriteLine( Text5.Length )
	Console.WriteLine("-------------------------------------")

	' 分割用のセパレータを作成	
	Dim separator As Char() = Encoding.ASCII.GetChars(ByteLf)
	' 配列
	Dim lines As String()

	' Lf で分割して配列を作成
	lines = Text5.Split( separator )

	Dim cnt As Integer = 0

	' 一行づつ表示
	Dim line As String
	For Each line In lines
		cnt += 1
		if cnt > 5 then
			Exit For
		end if

		Console.WriteLine(line)
	Next
	Console.WriteLine("-------------------------------------")

	' ********************************************************
	' VB.net ではセパレータは文字列でも良い
	' ********************************************************
	Dim separator2 As String = Encoding.ASCII.GetString(ByteLf)
	' 文字列の Lf で分割して配列を作成
	lines = Text5.Split( separator2 )

	cnt = 0

	' 一行づつ表示
	For Each line In lines
		cnt += 1
		if cnt > 5 then
			Exit For
		end if

		Console.WriteLine(line)
	Next
	Console.WriteLine("-------------------------------------")


	' ********************************************************
	' VB.net 用の名前空間にある定数でも良い
	' ********************************************************
	lines = Text5.Split( Microsoft.VisualBasic.ControlChars.Lf )

	cnt = 0

	' 一行づつ表示
	For Each line In lines
		cnt += 1
		if cnt > 5 then
			Exit For
		end if

		Console.WriteLine(line)
	Next
	Console.WriteLine("-------------------------------------")



End Sub

End Module