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Thread.CurrentThread Proprietà

Definizione

Ottiene il thread attualmente in esecuzione.

public:
 static property System::Threading::Thread ^ CurrentThread { System::Threading::Thread ^ get(); };
public static System.Threading.Thread CurrentThread { get; }
static member CurrentThread : System.Threading.Thread
Public Shared ReadOnly Property CurrentThread As Thread

Valore della proprietà

Oggetto Thread che rappresenta il thread attualmente in esecuzione.

Esempio

Nell'esempio seguente viene creata un'attività che a sua volta crea 20 attività figlio. L'applicazione stessa, nonché ogni attività, chiama il ShowThreadInformation metodo, che usa la CurrentThread proprietà per visualizzare informazioni sul thread in cui è in esecuzione.

using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;

public class Example
{
   private static Object lockObj = new Object();
   private static Object rndLock = new Object();

   public static void Main()
   {
      Random rnd = new Random();
      var tasks = new List<Task<Double>>();
      ShowThreadInformation("Application");

      Task<Double> t = Task.Run( () => { ShowThreadInformation("Main Task(Task #" + Task.CurrentId.ToString() + ")");
                                         for (int ctr = 1; ctr <= 20; ctr++)
                                           tasks.Add(Task.Factory.StartNew(
                                              () => { ShowThreadInformation("Task #" + Task.CurrentId.ToString());
                                                      long s = 0;
                                                      for (int n = 0; n <= 999999; n++) {
                                                         lock (rndLock) {
                                                            s += rnd.Next(1, 1000001);
                                                         }
                                                      }
                                                      return s/1000000.0;
                                                    } ));

                                        Task.WaitAll(tasks.ToArray());
                                        Double grandTotal = 0;
                                        Console.WriteLine("Means of each task: ");
                                        foreach (var child in tasks) {
                                           Console.WriteLine("   {0}", child.Result);
                                           grandTotal += child.Result;
                                        }
                                        Console.WriteLine();
                                        return grandTotal / 20;
                                   } );
      Console.WriteLine("Mean of Means: {0}", t.Result);
   }

  private static void ShowThreadInformation(String taskName)
  {
      String msg = null;
      Thread thread = Thread.CurrentThread;
      lock(lockObj) {
         msg = String.Format("{0} thread information\n", taskName) +
               String.Format("   Background: {0}\n", thread.IsBackground) +
               String.Format("   Thread Pool: {0}\n", thread.IsThreadPoolThread) +
               String.Format("   Thread ID: {0}\n", thread.ManagedThreadId);
      }
      Console.WriteLine(msg);
   }
}
// The example displays output like the following:
//       Application thread information
//          Background: False
//          Thread Pool: False
//          Thread ID: 1
//
//       Main Task(Task #1) thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #2 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #4 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #3 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #5 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #7 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 5
//
//       Task #6 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Task #8 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 6
//
//       Task #9 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 8
//
//       Task #10 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #11 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #12 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 6
//
//       Task #13 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #14 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #15 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Task #16 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 5
//
//       Task #17 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 8
//
//       Task #18 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #19 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #20 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #21 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Means of each task:
//          500038.740584
//          499810.422703
//          500217.558077
//          499868.534688
//          499295.505866
//          499893.475772
//          499601.454469
//          499828.532502
//          499606.183978
//          499700.276056
//          500415.894952
//          500005.874751
//          500042.237016
//          500092.764753
//          499998.798267
//          499623.054718
//          500018.784823
//          500286.865993
//          500052.68285
//          499764.363303
//
//       Mean of Means: 499908.10030605
open System
open System.Threading
open System.Threading.Tasks

let lockObj = obj ()
let rndLock = obj ()

let showThreadInformation taskName =
    let thread = Thread.CurrentThread

    lock lockObj (fun () ->
        printfn
            $"{taskName} thread information\n   Background: {thread.IsBackground}\n   Thread Pool: {thread.IsThreadPoolThread}\n   Thread ID: {thread.ManagedThreadId}\n")

let rnd = Random()
showThreadInformation "Application"

let t =
    Task.Run(fun () ->
        showThreadInformation $"Main Task(Task #{Task.CurrentId})"

        let tasks =
            [| for _ = 1 to 20 do
                   Task.Factory.StartNew(fun () ->
                       showThreadInformation $"Task #{Task.CurrentId}"
                       let mutable s = 0L

                       for n = 0 to 999999 do
                           lock rndLock (fun () -> s <- s + (rnd.Next(1, 1000001) |> int64))

                       float s / 1000000.) |]

        Task.WaitAll(box tasks :?> Task[])
        let mutable grandTotal = 0.
        printfn "Means of each task: "

        for child in tasks do
            printfn $"   {child.Result}"
            grandTotal <- grandTotal + child.Result

        printfn ""
        grandTotal / 20.)

printfn $"Mean of Means: {t.Result}"

// The example displays output like the following:
//       Application thread information
//          Background: False
//          Thread Pool: False
//          Thread ID: 1
//
//       Main Task(Task #1) thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #2 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #4 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #3 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #5 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #7 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 5
//
//       Task #6 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Task #8 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 6
//
//       Task #9 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 8
//
//       Task #10 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #11 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #12 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 6
//
//       Task #13 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #14 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 3
//
//       Task #15 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Task #16 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 5
//
//       Task #17 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 8
//
//       Task #18 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 9
//
//       Task #19 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 10
//
//       Task #20 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 4
//
//       Task #21 thread information
//          Background: True
//          Thread Pool: True
//          Thread ID: 7
//
//       Means of each task:
//          500038.740584
//          499810.422703
//          500217.558077
//          499868.534688
//          499295.505866
//          499893.475772
//          499601.454469
//          499828.532502
//          499606.183978
//          499700.276056
//          500415.894952
//          500005.874751
//          500042.237016
//          500092.764753
//          499998.798267
//          499623.054718
//          500018.784823
//          500286.865993
//          500052.68285
//          499764.363303
//
//       Mean of Means: 499908.10030605
Imports System.Collections.Generic
Imports System.Threading
Imports System.Threading.Tasks

Module Example
   Private lockObj As New Object()
   Private rndLock As New Object()
   
   Public Sub Main()
      Dim rnd As New Random()
      Dim tasks As New List(Of Task)
      ShowThreadInformation("Application")

      Dim t As Task(Of Double) = Task.Run( Function()
                                        ShowThreadInformation("Main Task(Task #" + Task.CurrentId.ToString() + ")")
                                        For ctr As Integer = 1 To 20
                                           tasks.Add(Task.Factory.StartNew( Function()
                                                                     ShowThreadInformation("Task #" + Task.CurrentId.ToString())
                                                                     Dim s As Long = 0
                                                                     For n As Integer = 0 To 999999
                                                                        SyncLock rndLock
                                                                           s += rnd.Next(1, 1000001)
                                                                        End SyncLock
                                                                     Next
                                                                     Return s/1000000
                                                                  End Function))
                                        Next

                                        Task.WaitAll(tasks.ToArray())
                                        Dim grandTotal As Double
                                        Console.WriteLine("Means of each task: ")
                                        For Each t In tasks
                                           Console.WriteLine("   {0}", t.Result)
                                           grandTotal += t.Result
                                        Next
                                        Console.WriteLine()
                                        Return grandTotal / 20
                                   End Function )
      Console.WriteLine("Mean of Means: {0}", t.Result)
   End Sub
   
   Private Sub ShowThreadInformation(taskName As String)
      Dim msg As String = Nothing
      Dim thread As Thread = Thread.CurrentThread
      SyncLock lockObj
         msg = String.Format("{0} thread information", taskName) + vbCrLf +
               String.Format("   Background: {0}", thread.IsBackground) + vbCrLf +
               String.Format("   Thread Pool: {0}", thread.IsThreadPoolThread) + vbCrLf +
               String.Format("   Thread ID: {0}", thread.ManagedThreadId) + vbCrLf
      End SyncLock
      Console.WriteLine(msg)
   End Sub
End Module
' The example displays output like the following:
'       Application thread information
'          Background: False
'          Thread Pool: False
'          Thread ID: 1
'
'       Main Task(Task #1) thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 3
'
'       Task #2 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 4
'
'       Task #4 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 10
'
'       Task #3 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 9
'
'       Task #5 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 3
'
'       Task #7 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 5
'
'       Task #6 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 7
'
'       Task #8 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 6
'
'       Task #9 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 8
'
'       Task #10 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 9
'
'       Task #11 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 10
'
'       Task #12 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 6
'
'       Task #13 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 4
'
'       Task #14 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 3
'
'       Task #15 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 7
'
'       Task #16 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 5
'
'       Task #17 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 8
'
'       Task #18 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 9
'
'       Task #19 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 10
'
'       Task #20 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 4
'
'       Task #21 thread information
'          Background: True
'          Thread Pool: True
'          Thread ID: 7
'
'       Means of each task:
'          500038.740584
'          499810.422703
'          500217.558077
'          499868.534688
'          499295.505866
'          499893.475772
'          499601.454469
'          499828.532502
'          499606.183978
'          499700.276056
'          500415.894952
'          500005.874751
'          500042.237016
'          500092.764753
'          499998.798267
'          499623.054718
'          500018.784823
'          500286.865993
'          500052.68285
'          499764.363303
'
'       Mean of Means: 499908.10030605/

Ogni attività figlio genera 1 milione di numeri casuali compresi tra 1 e 1 milione e restituisce la loro media. L'attività padre chiama il Task.WaitAll metodo per assicurarsi che le attività figlio siano state completate prima di visualizzare la media restituita da ogni attività e calcolando la media dei mezzi.

Si noti che durante l'esecuzione dell'applicazione in un thread in primo piano, ogni attività viene eseguita in un thread del pool di thread.

Si applica a