Imports System.IO
Imports System.Data.OleDb
Imports System.Runtime.Serialization.Formatters.Binary
Imports C1.C1Zip

Private Const FN_REGULAR = "\DataTable.regular"
Private Const FN_COMPRESSED = "\DataTable.compressed"
Private Const MDBFILE = " C:\Users\Documents\ComponentOne Samples\Common\C1NWIND.MDB"

Private Sub btnCreate_Click(sender As Object,e As EventArgs) Handles btnCreate.Click
 
    ' テーブルを開きます。
    Dim conn As String
    conn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & MDBFILE & ";"
    Dim rs As String = "select * from customers"
      ' ステータスを表示します。
    Cursor = Cursors.WaitCursor
    ToolStripStatusLabel1.Text = "Loading data from mdb file..."
     ' データをロードします。
    Dim da As OleDbDataAdapter = New OleDbDataAdapter(rs, conn)
    Dim ds As DataSet = New DataSet()
    Try
        da.Fill(ds)
    Catch
        MessageBox.Show("Could not load data from " + MDBFILE)
    End Try
     ' ステータスを表示します。
    Cursor = Cursors.Default
    ToolStripStatusLabel1.Text = "Loaded " & ds.Tables(0).Rows.Count & " records from mdb file."
     ' グリッドに連結します。
    DataGridView1.DataSource = ds.Tables(0)
     ' 保存ボタンを有効化します。
    btnSave.Enabled = True
End Sub

Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
     ' グリッドからデータテーブルを取得します。
    Dim dt As DataTable = DataGridView1.DataSource
     ' ステータスを表示します。
    Cursor = Cursors.WaitCursor
    ToolStripStatusLabel1.Text = "Serializing data to regular file..."
     ' データセットを通常のファイルにシリアライズします。
    Dim fn As String = Application.StartupPath + FN_REGULAR
    Dim fs As FileStream = New FileStream(fn, FileMode.Create)
    Dim bf As BinaryFormatter = New BinaryFormatter()
    bf.Serialize(fs, dt)
    Dim lenRegular As Long = fs.Length
    fs.Close()
     ' ステータスを表示します。
    Cursor = Cursors.WaitCursor
    ToolStripStatusLabel1.Text = "Serializing data to compressed file..."
     ' データセットを圧縮ファイルにシリアライズします。
    fn = Application.StartupPath & FN_COMPRESSED
    fs = New FileStream(fn, FileMode.Create)
    Dim compressor As C1ZStreamWriter = New C1ZStreamWriter(fs)
    bf = New BinaryFormatter()
    bf.Serialize(compressor, dt)
    Dim lenCompressed As Long = fs.Length
    fs.Close()
     ' ステータスを表示します。
    Cursor = Cursors.Default
    ToolStripStatusLabel1.Text = string.Format( "Saved to regular file ({0:#,###} bytes) and " & "compressed file ({1:#,###} bytes)", lenRegular, lenCompressed)
     ' ロードボタンを有効化します。
    btnLoad.Enabled = True
    btnLoadCompressed.Enabled = True
End Sub

Private Sub btnLoad_Click(sender As Object, e As EventArgs) Handles btnLoad.Click
     ' グリッドをクリアし、ステータスを表示します。
    Cursor = Cursors.WaitCursor
    DataGridView1.DataSource = Nothing
    ToolStripStatusLabel1.Text = "Loading from regular file..."
     ' 通常のファイルからシリアライズ解除します。
    Dim fn As String = Application.StartupPath & FN_REGULAR
    Dim fs As FileStream = New FileStream(fn, FileMode.Open)
    Dim ticks As Long = DateTime.Now.Ticks
    Dim bf As BinaryFormatter = New BinaryFormatter()
    Dim dt As DataTable = bf.Deserialize(fs)
    Dim ms As Long = (DateTime.Now.Ticks - ticks) / TimeSpan.TicksPerMillisecond
    fs.Close()
     ' 結果を表示します。
    Cursor = Cursors.Default
    DataGridView1.DataSource = dt
    ToolStripStatusLabel1.Text = "Loaded from regular file in " & ms.ToString() & " ms."
End Sub

Private Sub btnLoadCompressed_Click(sender As Object, e As EventArgs) Handles btnLoadCompressed.Click
      ' グリッドをクリアし、ステータスを表示します。
    Cursor = Cursors.WaitCursor
    DataGridView1.DataSource = Nothing
    ToolStripStatusLabel1.Text = "Loading from compressed file..."
      ' 圧縮ファイルからシリアライズ解除します。
    Dim fn As String = Application.StartupPath + FN_COMPRESSED
    Dim fs As FileStream = New FileStream(fn, FileMode.Open)
    Dim ticks As Long   = DateTime.Now.Ticks
    Dim decompressor As C1ZstreamReader
    decompressor = New C1ZStreamReader(fs)
    Dim bf As BinaryFormatter = New BinaryFormatter()
    Dim dt As DataTable = bf.Deserialize(decompressor)
    Dim ms As Long = (DateTime.Now.Ticks - ticks) / TimeSpan.TicksPerMillisecond
    fs.Close()
      ' 結果を表示します。
    Cursor = Cursors.Default
    DataGridView1.DataSource = dt
    ToolStripStatusLabel1.Text = "Loaded from compressed file in " & ms.ToString() & " ms."
End Sub