vb.netでバイナリファイル読み書き

vb.net

FilePut/FileGetというのがあって便利

public Class Form1

'バイナリファイル読み書きの練習
Public Structure Person
Public Name As String
Public Age As Short
End Structure
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'System.IOクラス
'BinaryWriter/Reader使用
Const filename = "F:\VB2005練習\バイナリファイル処理\test.dat"

Dim i As Integer = 5554444
Dim db As Double = Math.PI

'書き込み
Dim BFile As New System.IO.BinaryWriter(New System.IO.FileStream(filename, IO.FileMode.Create))
BFile.Write(i)
BFile.Write(db)
BFile.Close()

'読み込み
Dim i_r As Integer
Dim db_r As Double

Dim BRFile As New System.IO.BinaryReader(New System.IO.FileStream(filename, IO.FileMode.Open, IO.FileAccess.Read))
i_r = BRFile.ReadInt32() '読み込み時は型を指定しないといけない
db_r = BRFile.ReadDouble()
BRFile.Close()

Debug.WriteLine(i_r)
Debug.WriteLine(db_r)

End Sub


Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
'Microsoft.Visualbasic.FileSystemクラス
'FilePut/Get使用
Const filename = "F:\VB2005練習\バイナリファイル処理\test2.dat"

Dim i As Integer = 5554444
Dim db As Double = Math.PI

'書き込み
Dim n As Integer = FreeFile()
FileOpen(n, filename, OpenMode.Binary)
FilePut(n, i)
FilePut(n, db)
FileClose(n)

'読み込み
Dim i_r As Integer
Dim db_r As Double

n = FreeFile()
FileOpen(n, filename, OpenMode.Binary, OpenAccess.Read, OpenShare.LockWrite)
FileGet(n, i_r)
FileGet(n, db_r)
FileClose(n)

Debug.WriteLine(i_r)
Debug.WriteLine(db_r)

End Sub

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