Option Explicit On
Option Strict On
Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Label1.Text = "拡張子入力"
        Label2.Text = "フォルダパス"
        Label3.Text = "ファイル名"
        TextBox1.Text = "txt"
        TextBox2.Text = ""
        ListBox1.Text = ""
    End Sub

    Private Sub ToolStripButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ToolStripButton1.Click
        Dim dir As String = ""
        Dim ext As String = "*." & TextBox1.Text
        Dim fname As String = ""

        '**************************************************************************
        '選択したフォルダ内の，textBox1に入力された拡張子のファイル名を
        'listBoxに列挙する
        '**************************************************************************
        ListBox1.Items.Clear()
        FolderBrowserDialog1.Description = "フォルダを選択してください"
        If FolderBrowserDialog1.ShowDialog() = DialogResult.OK Then
            dir = FolderBrowserDialog1.SelectedPath
        End If
        TextBox2.Text = dir
        For Each fname In System.IO.Directory.GetFiles(dir, ext)
            ListBox1.Items.Add(System.IO.Path.GetFileName(fname))
        Next fname

    End Sub

    Private Sub ToolStripButton2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ToolStripButton2.Click
        Dim sw As System.IO.StreamWriter
        Dim fnameW As String = ""
        Dim i As Integer
        Dim dat As String

        '**************************************************************************
        'textBox2に掲示されているフォルダ名，ファイル数，listBoxに列挙された
        'ファイル名を，指定ファイルに書き出す
        '**************************************************************************
        SaveFileDialog1.InitialDirectory = System.IO.Directory.GetCurrentDirectory()
        If SaveFileDialog1.ShowDialog() = DialogResult.OK Then
            fnameW = SaveFileDialog1.FileName
        End If
        'データ書き込み
        sw = New System.IO.StreamWriter(fnameW, False, System.Text.Encoding.Default)
        dat = TextBox2.Text + "," + ListBox1.Items.Count.ToString()
        sw.WriteLine(dat)
        For i = 0 To ListBox1.Items.Count - 1
            dat = ListBox1.Items(i).ToString()
            sw.WriteLine(dat)
        Next i
        sw.Close()
    End Sub

End Class