FileSystemWatcher.EnableRaisingEvents プロパティ

.NET Framework クラス ライブラリ リファレンス

FileSystemWatcher.EnableRaisingEvents プロパティ

コンポーネントが有効かどうかを示す値を取得または設定します。

名前空間: System.IO
アセンブリ: System (system.dll 内)
構文

Visual Basic (宣言)

Public Property EnableRaisingEvents As
 Boolean

Visual Basic (使用法)

Dim instance As FileSystemWatcher
Dim value As Boolean

value = instance.EnableRaisingEvents

instance.EnableRaisingEvents = value

C#

public bool EnableRaisingEvents { get;
 set; }

C++

public:
property bool EnableRaisingEvents {
    bool get ();
    void set (bool value);
}

J#

/** @property */
public boolean get_EnableRaisingEvents ()

/** @property */
public void set_EnableRaisingEvents (boolean
 value)

JScript

public function get EnableRaisingEvents
 () : boolean

public function set EnableRaisingEvents
 (value : boolean)

プロパティ値
コンポーネントが有効な場合は true。それ以外の場合は false。既定値は false です。Visual Studio 2005 のデザイナでコンポーネントを使用する場合、既定は true です。

解説

コンポーネントは EnableRaisingEvents を true に設定しない限りイベントを発生させません。

メモ
コンポーネントは、Path プロパティが設定され、EnableRaisingEvents が true になるまで指定したディレクトリをウォッチしません。

WaitForChanged メソッドを使用すると、このプロパティが false に設定されている場合でも、イベント ハンドラを呼び出してファイル変更に対応できます。

使用例

実行時に指定したディレクトリをウォッチする FileSystemWatcher を作成する例を次に示します。コンポーネントは、ディレクトリのテキスト ファイルの LastWrite 時刻と LastAccess 時刻の変更、それらのファイルの作成、削除、名前の変更をウォッチするように設定されます。ファイルが変更、作成、または削除されると、そのファイルのパスがコンソールに表示されます。ファイルの名前を変更する場合は、古いパスと新しいパスがコンソールに出力されます。

この例では、System.Diagnostics 名前空間と System.IO 名前空間を使用します。

Visual Basic

Public Class Watcher
    
    Public Shared Sub Main()
    
         Run()
  
    End Sub

    <PermissionSet(SecurityAction.Demand, Name:="FullTrust")>
 _
    Private Shared Sub Run

      Dim args() As String
 = System.Environment.GetCommandLineArgs()
        ' If a directory is not specified, exit the program.
        If args.Length <> 2 Then
            ' Display the proper way to call the program.
            Console.WriteLine("Usage: Watcher.exe (directory)")
            Return
        End If
        
        ' Create a new FileSystemWatcher and set its properties.
        Dim watcher As New
 FileSystemWatcher()
        watcher.Path = args(1)
        ' Watch for changes in LastAccess and LastWrite times, and
        ' the renaming of files or directories. 
        watcher.NotifyFilter = (NotifyFilters.LastAccess Or NotifyFilters.LastWrite
 Or NotifyFilters.FileName Or NotifyFilters.DirectoryName)
        ' Only watch text files.
        watcher.Filter = "*.txt"
        
        ' Add event handlers.
        AddHandler watcher.Changed, AddressOf
 OnChanged
        AddHandler watcher.Created, AddressOf
 OnChanged
        AddHandler watcher.Deleted, AddressOf
 OnChanged
        AddHandler watcher.Renamed, AddressOf
 OnRenamed
        
        ' Begin watching.
        watcher.EnableRaisingEvents = True
        
        ' Wait for the user to quit the program.
        Console.WriteLine("Press 'q' to quit the sample.")
        While Chr(Console.Read()) <> "q"c
        End While
    End Sub
     
    ' Define the event handlers.
    Private Shared Sub OnChanged(source
 As Object, e As FileSystemEventArgs)
        ' Specify what is done when a file is changed, created, or deleted.
        Console.WriteLine("File: " & e.FullPath
 & " " & e.ChangeType)
    End Sub    
    
    Private Shared Sub OnRenamed(source
 As Object, e As RenamedEventArgs)
        ' Specify what is done when a file is renamed.
        Console.WriteLine("File: {0} renamed to {1}",
 e.OldFullPath, e.FullPath)
    End Sub
    
End Class

C#

public class Watcher
{

    public static void Main()
    {
    Run();

    }

    [PermissionSet(SecurityAction.Demand, Name="FullTrust")]
    public static void Run()
    {
        string[] args = System.Environment.GetCommandLineArgs();
 
        // If a directory is not specified, exit program.
        if(args.Length != 2)
        {
            // Display the proper way to call the program.
            Console.WriteLine("Usage: Watcher.exe (directory)");
            return;
        }

        // Create a new FileSystemWatcher and set its properties.
        FileSystemWatcher watcher = new FileSystemWatcher();
        watcher.Path = args[1];
        /* Watch for changes in LastAccess
 and LastWrite times, and 
           the renaming of files or directories. */
        watcher.NotifyFilter = NotifyFilters.LastAccess | NotifyFilters.LastWrite
 
           | NotifyFilters.FileName | NotifyFilters.DirectoryName;
        // Only watch text files.
        watcher.Filter = "*.txt";

        // Add event handlers.
        watcher.Changed += new FileSystemEventHandler(OnChanged);
        watcher.Created += new FileSystemEventHandler(OnChanged);
        watcher.Deleted += new FileSystemEventHandler(OnChanged);
        watcher.Renamed += new RenamedEventHandler(OnRenamed);

        // Begin watching.
        watcher.EnableRaisingEvents = true;

        // Wait for the user to quit the program.
        Console.WriteLine("Press \'q\' to quit the sample.");
        while(Console.Read()!='q');
    }

    // Define the event handlers.
    private static void
 OnChanged(object source, FileSystemEventArgs e)
    {
        // Specify what is done when a file is changed, created, or
 deleted.
       Console.WriteLine("File: " +  e.FullPath + " " + e.ChangeType);
    }

    private static void
 OnRenamed(object source, RenamedEventArgs e)
    {
        // Specify what is done when a file is renamed.
        Console.WriteLine("File: {0} renamed to {1}", e.OldFullPath, e.FullPath);
    }
}

C++

public ref class Watcher
{
private:
   // Define the event handlers.
   static void OnChanged( Object^ /*source*/,
 FileSystemEventArgs^ e )
   {
      // Specify what is done when a file is changed, created, or deleted.
      Console::WriteLine( "File: {0} {1}", e->FullPath, e->ChangeType
 );
   }

   static void OnRenamed( Object^ /*source*/,
 RenamedEventArgs^ e )
   {
      // Specify what is done when a file is renamed.
      Console::WriteLine( "File: {0} renamed to {1}", e->OldFullPath,
 e->FullPath );
   }

public:
   [PermissionSet(SecurityAction::Demand, Name="FullTrust")]
   int static run()
   {
      array<String^>^args = System::Environment::GetCommandLineArgs();

      // If a directory is not specified, exit program.
      if ( args->Length != 2 )
      {
         // Display the proper way to call the program.
         Console::WriteLine( "Usage: Watcher.exe (directory)" );
         return 0;
      }

      // Create a new FileSystemWatcher and set its properties.
      FileSystemWatcher^ watcher = gcnew FileSystemWatcher;
      watcher->Path = args[ 1 ];

      /* Watch for changes in LastAccess and
 LastWrite times, and 
          the renaming of files or directories. */
      watcher->NotifyFilter = static_cast<NotifyFilters>(NotifyFilters::LastAccess
 |
            NotifyFilters::LastWrite | NotifyFilters::FileName | NotifyFilters::DirectoryName);

      // Only watch text files.
      watcher->Filter = "*.txt";

      // Add event handlers.
      watcher->Changed += gcnew FileSystemEventHandler( Watcher::OnChanged );
      watcher->Created += gcnew FileSystemEventHandler( Watcher::OnChanged );
      watcher->Deleted += gcnew FileSystemEventHandler( Watcher::OnChanged );
      watcher->Renamed += gcnew RenamedEventHandler( Watcher::OnRenamed );

      // Begin watching.
      watcher->EnableRaisingEvents = true;

      // Wait for the user to quit the program.
      Console::WriteLine( "Press \'q\' to quit the sample." );
      while ( Console::Read() != 'q' )
         ;
   }
};

int main() {
   Watcher::run();
}

J#

public class Watcher
{
    public static void main(String[]
 args1)
    {
    Run();
    } 

    /** @attribute PermissionSet(SecurityAction.Demand, Name="FullTrust")
     */
    public static void Run()
    {
        String args[] = System.Environment.GetCommandLineArgs();

        // If a directory is not specified, exit program.
        if (args.length != 2) {

            // Display the proper way to call the program.
            Console.WriteLine("Usage: Watcher.exe (directory)");
            return;
        }

        // Create a new FileSystemWatcher and set its properties.
        FileSystemWatcher watcher = new FileSystemWatcher();
        watcher.set_Path(args[1]);

        /* Watch for changes in LastAccess
 and LastWrite times, and 
           the renaming of files or directories.
         */
        watcher.set_NotifyFilter
            (NotifyFilters.LastAccess |NotifyFilters.LastWrite |
            NotifyFilters.FileName | NotifyFilters.DirectoryName);

        // Only watch text files.
        watcher.set_Filter("*.txt");

        // Add event handlers.
        watcher.add_Changed(new FileSystemEventHandler(OnChanged));
        watcher.add_Created(new FileSystemEventHandler(OnChanged));
        watcher.add_Deleted(new FileSystemEventHandler(OnChanged));
        watcher.add_Renamed(new RenamedEventHandler(OnRenamed));

        // Begin watching.
        watcher.set_EnableRaisingEvents(true);

        // Wait for the user to quit the program.
        Console.WriteLine("Press \'q\' to quit the sample.");
        while ((Console.Read() != 'q')) {

        }
    }

    // Define the event handlers.
    private static void
 OnChanged(Object source,FileSystemEventArgs e)
    {
        // Specify what is done when a file is changed, created, or
 deleted.
        Console.WriteLine(("File: " + e.get_FullPath() + " "
 
            + e.get_ChangeType()));
    } //OnChanged

    private static void
 OnRenamed(Object source, RenamedEventArgs e)
    {
        // Specify what is done when a file is renamed.
        Console.WriteLine("File: {0} renamed to {1}",
            e.get_OldFullPath(),e.get_FullPath());
    } //OnRenamed
} //Watcher

プラットフォーム

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0、1.1、1.0

参照

関連項目
FileSystemWatcher クラス
FileSystemWatcher メンバ
System.IO 名前空間