ファイルやフォルダの変更を監視する方法

ファイルやフォルダの変更を監視する方法
VB.NET

Dim watcher As New System.IO.FileSystemWatcher
watcher.Path = "C:\docs"
watcher.Filter = "*.txt"
watcher.NotifyFilter = System.IO.NotifyFilters.FileName Or _
    System.IO.NotifyFilters.DirectoryName Or _
    System.IO.NotifyFilters.LastWrite
watcher.IncludeSubdirectories = False

Dim changedResult As System.IO.WaitForChangedResult = _

    watcher.WaitForChanged(System.IO.WatcherChangeTypes.All)

If changedResult.TimedOut Then
    Console.WriteLine("タイムアウト")
    Return
End If

Select Case changedResult.ChangeType
    Case System.IO.WatcherChangeTypes.Changed
        Console.WriteLine(("ファイル 「" + _
            changedResult.Name + "」変更"))
    Case System.IO.WatcherChangeTypes.Created
        Console.WriteLine(("ファイル 「" + _
            changedResult.Name + "」作成"))
    Case System.IO.WatcherChangeTypes.Deleted
        Console.WriteLine(("ファイル 「" + _
            changedResult.Name + "」削除"))
    Case System.IO.WatcherChangeTypes.Renamed
        Console.WriteLine(("ファイル 「" + _
            changedResult.OldName + "」「" + _
            changedResult.Name + "」変更。"))
End Select

C#

System.IO.FileSystemWatcher watcher =
    new System.IO.FileSystemWatcher();
watcher.Path = @"C:\My Documents";
watcher.Filter = "*.txt";
watcher.NotifyFilter = 
    System.IO.NotifyFilters.FileName
    | System.IO.NotifyFilters.DirectoryName
    | System.IO.NotifyFilters.LastWrite;
watcher.IncludeSubdirectories = false;

System.IO.WaitForChangedResult changedResult =

    watcher.WaitForChanged(System.IO.WatcherChangeTypes.All);

if (changedResult.TimedOut)
{
    Console.WriteLine("タイムアウト!!です");
    return;
}

switch (changedResult.ChangeType)
{
    case System.IO.WatcherChangeTypes.Changed:
        Console.WriteLine(
            "ファイル 「" + changedResult.Name + "」変更");
        break;
    case System.IO.WatcherChangeTypes.Created:
        Console.WriteLine(
            "ファイル 「" + changedResult.Name + "」作成");
        break;
    case System.IO.WatcherChangeTypes.Deleted:
        Console.WriteLine(
            "ファイル 「" + changedResult.Name + "」削除");
        break;
    case System.IO.WatcherChangeTypes.Renamed:
        Console.WriteLine(
            "ファイル 「" + changedResult.OldName +
            "」名前「" + changedResult.Name +
            "」変更");
        break;
}

フォルダやファイルの変更を監視する方法（非同期）
VB.NET

Private watcher As System.IO.FileSystemWatcher = Nothing

Private Sub btn1_Click(ByVal sender As Object, _
    ByVal e As System.EventArgs) Handles btn1.Click
    If Not (watcher Is Nothing) Then
        Return
    End If

    watcher = New System.IO.FileSystemWatcher
    watcher.Path = "C:\My Documents"
    watcher.NotifyFilter = System.IO.NotifyFilters.LastAccess Or _
        System.IO.NotifyFilters.LastWrite Or _
        System.IO.NotifyFilters.FileName Or _
        System.IO.NotifyFilters.DirectoryName
    watcher.Filter = ""
    watcher.SynchronizingObject = Me

    AddHandler watcher.Changed, AddressOf watcher_Changed
    AddHandler watcher.Created, AddressOf watcher_Changed
    AddHandler watcher.Deleted, AddressOf watcher_Changed
    AddHandler watcher.Renamed, AddressOf watcher_Renamed

    watcher.EnableRaisingEvents = True
    Console.WriteLine("監視開始")
End Sub

Private Sub btn2_Click(ByVal sender As Object, _
    ByVal e As System.EventArgs) Handles btn2.Click
    watcher.EnableRaisingEvents = False
    watcher.Dispose()
    watcher = Nothing
    Console.WriteLine("監視終了")
End Sub

'イベントハンドラ
Private Sub watcher_Changed(ByVal source As System.Object, _
    ByVal e As System.IO.FileSystemEventArgs)
    Select Case e.ChangeType
        Case System.IO.WatcherChangeTypes.Changed
            Console.WriteLine(("ファイル 「" + e.FullPath + _
                "」変更"))
        Case System.IO.WatcherChangeTypes.Created
            Console.WriteLine(("ファイル 「" + e.FullPath + _
                "」作成"))
        Case System.IO.WatcherChangeTypes.Deleted
            Console.WriteLine(("ファイル 「" + e.FullPath + _
                "」削除"))
    End Select
End SubPrivate Sub watcher_Renamed(ByVal source As System.Object, _

    ByVal e As System.IO.RenamedEventArgs)
    Console.WriteLine(("ファイル 「" + e.FullPath + _
        "」名前変更"))
End Sub

C#

private System.IO.FileSystemWatcher watcher = null;

private void btn1_Click(object sender, System.EventArgs e)

{
    if (watcher != null) return;

    watcher = new System.IO.FileSystemWatcher();
    watcher.Path = @"C:\docs";
    watcher.NotifyFilter =
        (System.IO.NotifyFilters.LastAccess 
        | System.IO.NotifyFilters.LastWrite
        | System.IO.NotifyFilters.FileName 
        | System.IO.NotifyFilters.DirectoryName);
    watcher.Filter = "";
    watcher.SynchronizingObject = this;

    watcher.Changed += new System.IO.FileSystemEventHandler(watcher_Changed);
    watcher.Created += new System.IO.FileSystemEventHandler(watcher_Changed);
    watcher.Deleted += new System.IO.FileSystemEventHandler(watcher_Changed);
    watcher.Renamed += new System.IO.RenamedEventHandler(watcher_Renamed);

    watcher.EnableRaisingEvents = true;
    Console.WriteLine("監視開始");
}

private void btn2_Click(object sender, System.EventArgs e)

{
    watcher.EnableRaisingEvents = false;
    watcher.Dispose();
    watcher = null;
    Console.WriteLine("監視終了");
}

private void watcher_Changed(System.Object source,
    System.IO.FileSystemEventArgs e)
{
    switch (e.ChangeType)
    {
        case System.IO.WatcherChangeTypes.Changed:
            Console.WriteLine(
                "ファイル 「" + e.FullPath + "」変更");
            break;
        case System.IO.WatcherChangeTypes.Created:
            Console.WriteLine(
                "ファイル 「" + e.FullPath + "」作成");
            break;
        case System.IO.WatcherChangeTypes.Deleted:
            Console.WriteLine(
                "ファイル 「" + e.FullPath + "」削除");
            break;
    }
}

private void watcher_Renamed(System.Object source, 
    System.IO.RenamedEventArgs e)
{
    Console.WriteLine(
        "ファイル 「" + e.FullPath + "」名前変更");
}