ElapsedEventHandler デリゲートとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

索引トップ用語の索引ランキング

ElapsedEventHandler デリゲート

Timer の Elapsed イベントを処理するメソッドを表します。

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

Visual Basic (宣言)

Public Delegate Sub ElapsedEventHandler
 ( _
    sender As Object, _
    e As ElapsedEventArgs _
)

Visual Basic (使用法)

Dim instance As New ElapsedEventHandler(AddressOf
 HandlerMethod)

public delegate void ElapsedEventHandler (
    Object sender,
    ElapsedEventArgs e
)

C++

public delegate void ElapsedEventHandler (
    Object^ sender, 
    ElapsedEventArgs^ e
)

/** @delegate */
public delegate void ElapsedEventHandler (
    Object sender, 
    ElapsedEventArgs e
)

JScript

JScript では、デリゲートは使用できますが、新規に宣言することはできません。

パラメータ

sender: イベントのソース。

e: イベントデータを格納している ElapsedEventArgs オブジェクト。

解説

ElapsedEventHandler デリゲートを作成する場合は、イベントを処理するメソッドを識別してください。イベントをイベントハンドラに関連付けるには、デリゲートのインスタンスをイベントに追加します。デリゲートを削除しない限り、そのイベントが発生すると常にイベントハンドラが呼び出されます。イベントハンドラデリゲートの詳細については、「イベントとデリゲート」を参照してください。

使用例

Visual Basic

Imports System
Imports System.Timers

Public Class Timer1
    
    Public Shared Sub Main()
        ' Normally, the timer is declared at the class level, so
        ' that it doesn't go out of scope when the method ends.
        ' In this example, the timer is needed only while Main 
        ' is executing. However, KeepAlive must be used at the
        ' end of Main, to prevent the JIT compiler from allowing 
        ' aggressive garbage collection to occur before Main 
        ' ends.
        Dim aTimer As New
 System.Timers.Timer()

        ' Hook up the Elapsed event for the timer.
        AddHandler aTimer.Elapsed, AddressOf
 OnTimedEvent

        ' Set the Interval to 2 seconds (2000 milliseconds).
        aTimer.Interval = 2000
        aTimer.Enabled = True
        
        Console.WriteLine("Press the Enter key to exit the program.")
        Console.ReadLine()

        ' Keep the timer alive until the end of Main.
        GC.KeepAlive(aTimer)
    End Sub
        
    ' Specify what you want to happen when the Elapsed event is 
    ' raised.
    Private Shared Sub OnTimedEvent(source
 As Object, e As ElapsedEventArgs)
        Console.WriteLine("Hello World!")
    End Sub
End Class

using System;
using System.Timers;

public class Timer1
{
    public static void Main()
    {
        // Normally, the timer is declared at the class level, so
        // that it doesn't go out of scope when the method ends.
        // In this example, the timer is needed only while Main 
        // is executing. However, KeepAlive must be used at the
        // end of Main, to prevent the JIT compiler from allowing 
        // aggressive garbage collection to occur before Main 
        // ends.
        System.Timers.Timer aTimer = new System.Timers.Timer();

        // Hook up the Elapsed event for the timer.
        aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);

        // Set the Interval to 2 seconds (2000 milliseconds).
        aTimer.Interval = 2000;
        aTimer.Enabled = true;
 
        Console.WriteLine("Press the Enter key to exit the program.");
        Console.ReadLine();

        // Keep the timer alive until the end of Main.
        GC.KeepAlive(aTimer);
    }
 
    // Specify what you want to happen when the Elapsed event is 
    // raised.
    private static void
 OnTimedEvent(object source, ElapsedEventArgs e)
    {
        Console.WriteLine("Hello World!");
    }
}

C++

#using <system.dll>

using namespace System;
using namespace System::Timers;

public ref class Timer1
{
public:
   static void Demo()
   {
      // Normally, the timer is declared at the class level, so
      // that it doesn't go out of scope when the method ends.
      // In this example, the timer is needed only while Demo
      // is executing. However, KeepAlive must be used at the
      // end of Demo, to prevent the JIT compiler from allowing 
      // aggressive garbage collection to occur before Demo
      // ends.
      System::Timers::Timer^ aTimer = gcnew System::Timers::Timer;

      // Hook up the Elapsed event for the timer.
      aTimer->Elapsed += gcnew ElapsedEventHandler( Timer1::OnTimedEvent );
      
      // Set the Interval to 2 seconds (2000 milliseconds).
      aTimer->Interval = 2000;
      aTimer->Enabled = true;

      Console::WriteLine("Press the Enter key to exit the program.");
      Console::ReadLine();

      // Keep the timer alive until the end of the Demo method.
      GC::KeepAlive(aTimer);
   }


private:
   // Specify what you want to happen when the Elapsed event is 
   // raised.
   static void OnTimedEvent( Object^ /*source*/,
 ElapsedEventArgs^ /*e*/ )
   {
      Console::WriteLine( "Hello World!" );
   }

};

int main()
{
   Timer1::Demo();
}