Thread.Priority Vlastnost

Definice

Získává nebo nastavuje hodnotu, která indikuje prioritu plánování vlákna.Gets or sets a value indicating the scheduling priority of a thread.

public:
 property System::Threading::ThreadPriority Priority { System::Threading::ThreadPriority get(); void set(System::Threading::ThreadPriority value); };
public System.Threading.ThreadPriority Priority { get; set; }
member this.Priority : System.Threading.ThreadPriority with get, set
Public Property Priority As ThreadPriority

Hodnota vlastnosti

Jedna z hodnot ThreadPriority.One of the ThreadPriority values. Výchozí hodnota je Normal.The default value is Normal.

Výjimky

Vlákno dosáhlo konečného stavu, například Aborted.The thread has reached a final state, such as Aborted.

Hodnota zadaná pro operaci set není platná hodnota ThreadPriority.The value specified for a set operation is not a valid ThreadPriority value.

Příklady

Následující příklad ukazuje výsledek změny priority vlákna.The following example shows the result of changing the priority of a thread. Vytvoří se tři vlákna, priorita jednoho vlákna je nastavená na ThreadPriority.BelowNormala priorita druhé je nastavená na ThreadPriority.AboveNormal.Three threads are created, the priority of one thread is set to ThreadPriority.BelowNormal, and the priority of a second is set to ThreadPriority.AboveNormal. Každé vlákno zvýší proměnnou ve while smyčce a spustí se pro nastavený čas.Each thread increments a variable in a while loop and runs for a set time.

using System;
using System.Threading;
using Timers = System.Timers;

class Test
{
    static void Main()
    {
        PriorityTest priorityTest = new PriorityTest();

        Thread thread1 = new Thread(priorityTest.ThreadMethod);
        thread1.Name = "ThreadOne";
        Thread thread2 = new Thread(priorityTest.ThreadMethod);
        thread2.Name = "ThreadTwo";
        thread2.Priority = ThreadPriority.BelowNormal;
        Thread thread3 = new Thread(priorityTest.ThreadMethod);
        thread3.Name = "ThreadThree";
        thread3.Priority = ThreadPriority.AboveNormal;

        thread1.Start();
        thread2.Start();
        thread3.Start();
        // Allow counting for 10 seconds.
        Thread.Sleep(10000);
        priorityTest.LoopSwitch = false;
    }
}

class PriorityTest
{
    static bool loopSwitch;
    [ThreadStatic] static long threadCount = 0;

    public PriorityTest()
    {
        loopSwitch = true;
    }

    public bool LoopSwitch
    {
        set{ loopSwitch = value; }
    }

    public void ThreadMethod()
    {
        while(loopSwitch)
        {
            threadCount++;
        }
        Console.WriteLine("{0,-11} with {1,11} priority " +
            "has a count = {2,13}", Thread.CurrentThread.Name, 
            Thread.CurrentThread.Priority.ToString(), 
            threadCount.ToString("N0")); 
    }
}
// The example displays output like the following:
//    ThreadOne   with      Normal priority has a count =   755,897,581
//    ThreadThree with AboveNormal priority has a count =   778,099,094
//    ThreadTwo   with BelowNormal priority has a count =     7,840,984
Imports System.Threading
Imports Timers = System.Timers

Public Module Example
   Dim t As Timers.Timer
   Private priorityTest As New PriorityTest()

    Public Sub Main()
        Dim thread1 As New Thread(AddressOf priorityTest.ThreadMethod)
        thread1.Name = "ThreadOne"
        Dim thread2 As New Thread(AddressOf priorityTest.ThreadMethod)
        thread2.Name = "ThreadTwo"
        thread2.Priority = ThreadPriority.BelowNormal
        Dim thread3 As New Thread(AddressOf priorityTest.ThreadMethod)
        thread3.Name = "ThreadThree"
        thread3.Priority = ThreadPriority.AboveNormal
        thread1.Start()
        thread2.Start()
        thread3.Start()

        ' Allow threads to execute for about 10 seconds.
        t = New Timers.Timer()
        t.AutoReset = False
        t.Interval = 10000
        AddHandler t.Elapsed, AddressOf Elapsed
        t.Start()
    End Sub

    Private Sub Elapsed(sender As Object, e As Timers.ElapsedEventArgs)
       priorityTest.LoopSwitch = False
    End Sub
End Module

Public Class PriorityTest
    Private Shared loopSwitchValue As Boolean
    <ThreadStatic> Shared threadCount As Long

    Sub New()
        loopSwitchValue = True
    End Sub

    WriteOnly Property LoopSwitch As Boolean
        Set
            loopSwitchValue = Value
        End Set
    End Property

    Sub ThreadMethod()
        Do While True
            threadCount += 1
            If Not loopSwitchValue Then Exit Do
        Loop

        Console.WriteLine("{0,-11} with {1,11} priority " &
            "has a count = {2,13}", Thread.CurrentThread.Name,
            Thread.CurrentThread.Priority.ToString(),
            threadCount.ToString("N0")) 
    End Sub
End Class
' The example displays the following output:
'    ThreadOne   with      Normal priority has a count =   755,897,581
'    ThreadThree with AboveNormal priority has a count =   778,099,094
'    ThreadTwo   with BelowNormal priority has a count =     7,840,984

Poznámky

K vláknu lze přiřadit jednu z následujících hodnot priority ThreadPriority:A thread can be assigned any one of the following priority ThreadPriority values:

  • Highest

  • AboveNormal

  • Normal

  • BelowNormal

  • Lowest

Operační systémy nejsou vyžadovány pro respektování priority vlákna.Operating systems are not required to honor the priority of a thread.

Platí pro

Viz také