WaitHandle.WaitTimeout フィールド

.NET Framework クラス ライブラリ リファレンス

WaitHandle.WaitTimeout フィールド

待機ハンドルがシグナル状態になる前に WaitAny 操作がタイムアウトになったことを示します。このフィールドは定数です。

名前空間: System.Threading
アセンブリ: mscorlib (mscorlib.dll 内)
構文

Visual Basic (宣言)

Public Const WaitTimeout As
 Integer

Visual Basic (使用法)

Dim value As Integer

value = WaitHandle.WaitTimeout

C#

public const int WaitTimeout

C++

public:
literal int WaitTimeout

J#

public static final int
 WaitTimeout

JScript

public const var WaitTimeout
 : int

解説

このフィールドは、WaitAny の有効な戻り値の 1 つです。

使用例

スレッド プールを使用して、ファイルを複数のディスク上で同時に検索する方法の例を次に示します。ここでは、各ディスクのルート ディレクトリだけを検索します。

Visual Basic

Imports Microsoft.VisualBasic
Imports System
Imports System.IO
Imports System.Threading

Public Class Test

    <MTAThread> _
    Shared Sub Main()
        Dim search As New
 Search()
        search.FindFile("SomeFile.dat")
    End Sub    
End Class

Public Class Search

    ' Maintain state information to pass to FindCallback.
    Class State
        Public autoEvent As AutoResetEvent
 
        Public fileName As String
         

        Sub New(anEvent As
 AutoResetEvent, fName As String)
            autoEvent = anEvent
            fileName = fName
        End Sub
    End Class

    Dim autoEvents() As AutoResetEvent
    Dim diskLetters() As String

    Sub New()

        ' Retrieve an array of disk letters.
        diskLetters = Environment.GetLogicalDrives()

        autoEvents = New AutoResetEvent(diskLetters.Length - 1)
 {}
        For i As Integer
 = 0 To diskLetters.Length - 1
            autoEvents(i) = New AutoResetEvent(False)
        Next i
    End Sub    
    
    ' Search for fileName in the root directory of all disks.
    Sub FindFile(fileName As String)
        For i As Integer
 = 0 To diskLetters.Length - 1
            Console.WriteLine("Searching for {0} on {1}.",
 _
                fileName, diskLetters(i))
        
            ThreadPool.QueueUserWorkItem(AddressOf FindCallback,
 _ 
                New State(autoEvents(i), diskLetters(i) &
 fileName))
        Next i

        ' Wait for the first instance of the file to be found.
        Dim index As Integer
 = _
            WaitHandle.WaitAny(autoEvents, 3000, False)
        If index = WaitHandle.WaitTimeout
            Console.WriteLine(vbCrLf & "{0} not found.",
 fileName)
        Else
            Console.WriteLine(vbCrLf & "{0} found on {1}.",
 _
                fileName, diskLetters(index))
        End If
    End Sub

    ' Search for stateInfo.fileName.
    Sub FindCallback(state As Object)
        Dim stateInfo As State = DirectCast(state,
 State)

        ' Signal if the file is found.
        If File.Exists(stateInfo.fileName) Then
            stateInfo.autoEvent.Set()
        End If
    End Sub

End Class

C#

using System;
using System.IO;
using System.Threading;

class Test
{
    static void Main()
    {
        Search search = new Search();
        search.FindFile("SomeFile.dat");
    }
}

class Search
{
    // Maintain state information to pass to FindCallback.
    class State
    {
        public AutoResetEvent autoEvent;
        public string         fileName;

        public State(AutoResetEvent autoEvent, string
 fileName)
        {
            this.autoEvent    = autoEvent;
            this.fileName     = fileName;
        }
    }

    AutoResetEvent[] autoEvents;
    String[] diskLetters;

    public Search()
    {
        // Retrieve an array of disk letters.
        diskLetters = Environment.GetLogicalDrives();

        autoEvents = new AutoResetEvent[diskLetters.Length];
        for(int i = 0; i < diskLetters.Length;
 i++)
        {
            autoEvents[i] = new AutoResetEvent(false);
        }
    }

    // Search for fileName in the root directory of all disks.
    public void FindFile(string
 fileName)
    {
        for(int i = 0; i < diskLetters.Length;
 i++)
        {
            Console.WriteLine("Searching for {0} on {1}."
,
                fileName, diskLetters[i]);
            ThreadPool.QueueUserWorkItem(
                new WaitCallback(FindCallback), 
                new State(autoEvents[i], diskLetters[i] + fileName));
        }

        // Wait for the first instance of the file to be found.
        int index = WaitHandle.WaitAny(autoEvents, 3000, false);
        if(index == WaitHandle.WaitTimeout)
        {
            Console.WriteLine("\n{0} not found.", fileName);
        }
        else
        {
            Console.WriteLine("\n{0} found on {1}.", fileName,
                diskLetters[index]);
        }
    }

    // Search for stateInfo.fileName.
    void FindCallback(object state)
    {
        State stateInfo = (State)state;

        // Signal if the file is found.
        if(File.Exists(stateInfo.fileName))
        {
            stateInfo.autoEvent.Set();
        }
    }
}

C++

using namespace System;
using namespace System::IO;
using namespace System::Threading;
ref class Search
{
private:

   // Maintain state information to pass to FindCallback.
   ref class State
   {
   public:
      AutoResetEvent^ autoEvent;
      String^ fileName;
      State( AutoResetEvent^ autoEvent, String^ fileName )
         : autoEvent( autoEvent ), fileName( fileName )
      {}

   };


public:
   array<AutoResetEvent^>^autoEvents;
   array<String^>^diskLetters;

   // Search for stateInfo->fileName.
   void FindCallback( Object^ state )
   {
      State^ stateInfo = dynamic_cast<State^>(state);
      
      // Signal if the file is found.
      if ( File::Exists( stateInfo->fileName ) )
      {
         stateInfo->autoEvent->Set();
      }
   }

   Search()
   {
      
      // Retrieve an array of disk letters.
      diskLetters = Environment::GetLogicalDrives();
      autoEvents = gcnew array<AutoResetEvent^>(diskLetters->Length);
      for ( int i = 0; i < diskLetters->Length;
 i++ )
      {
         autoEvents[ i ] = gcnew AutoResetEvent( false );

      }
   }


   // Search for fileName in the root directory of all disks.
   void FindFile( String^ fileName )
   {
      for ( int i = 0; i < diskLetters->Length;
 i++ )
      {
         Console::WriteLine(  "Searching for {0} on {1}.",
 fileName, diskLetters[ i ] );
         ThreadPool::QueueUserWorkItem( gcnew WaitCallback( this,
 &Search::FindCallback ), gcnew State( autoEvents[ i ],String::Concat( diskLetters[
 i ], fileName ) ) );

      }
      
      // Wait for the first instance of the file to be found.
      int index = WaitHandle::WaitAny( autoEvents, 3000, false
 );
      if ( index == WaitHandle::WaitTimeout )
      {
         Console::WriteLine( "\n{0} not found.", fileName );
      }
      else
      {
         Console::WriteLine( "\n{0} found on {1}.", fileName, diskLetters[
 index ] );
      }
   }

};

int main()
{
   Search^ search = gcnew Search;
   search->FindFile( "SomeFile.dat" );
}

J#

import System.*;
import System.IO.*;
import System.Threading.*;

class Test
{
    public static void main(String[]
 args)
    {
        Search search = new Search();
        search.FindFile("SomeFile.dat");
    } //main
} //Test

class Search
{
    // Maintain state information to pass to FindCallback.
    class State
    {
        public AutoResetEvent autoEvent;
        public String fileName;

        public State(AutoResetEvent autoEvent, String fileName)
        {
            this.autoEvent = autoEvent;
            this.fileName = fileName;
        } //State
    } //State

    private AutoResetEvent autoEvents[];
    private String diskLetters[];

    public Search()
    {
        // Retrieve an array of disk letters.
        diskLetters = Environment.GetLogicalDrives();
        autoEvents = new AutoResetEvent[diskLetters.length];
        for (int i = 0; i < diskLetters.length;
 i++) {
            autoEvents[i] = new AutoResetEvent(false);
        }
    } //Search

    // Search for fileName in the root directory of all disks.
    public void FindFile(String fileName)
    {
        for (int i = 0; i < diskLetters.length;
 i++) {
            Console.WriteLine("Searching for {0} on {1}."
, fileName,
                diskLetters.get_Item(i));
            ThreadPool.QueueUserWorkItem(new WaitCallback(FindCallback),
 
                new State(autoEvents[i], diskLetters[i] + fileName));
        }

        // Wait for the first instance of the file to be found.
        int index = WaitHandle.WaitAny(autoEvents, 3000, false);

        if (index == WaitHandle.WaitTimeout) {
            Console.WriteLine("\n{0} not found.", fileName);
        }
        else {
            Console.WriteLine("\n{0} found on {1}.", fileName,
                diskLetters.get_Item(index));
        }
    } //FindFile

    // Search for stateInfo.fileName.
    void FindCallback(Object state)
    {
        State stateInfo = ((State)(state));

        // Signal if the file is found.
        if (File.Exists(stateInfo.fileName)) {
            stateInfo.autoEvent.Set();
        }
    } //FindCallback
} //Search

プラットフォーム

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, 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
WaitHandle クラス
WaitHandle メンバ
System.Threading 名前空間