Thread.Priority Vlastnost
Důležité
Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.
Získává nebo nastavuje hodnotu, která indikuje prioritu plánování vlákna.
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, setPublic Property Priority As ThreadPriorityJedna z ThreadPriority hodnot. Výchozí hodnota je Normal.
Vlákno dosáhlo konečného stavu, například Aborted .
Hodnota zadaná pro operaci set není platná ThreadPriority hodnota.
Následující příklad ukazuje výsledek změny priority vlákna. Tři vlákna jsou vytvořena, priorita jednoho vlákna je nastavena na hodnotu ThreadPriority.BelowNormal a priorita druhé je nastavena na hodnotu ThreadPriority.AboveNormal . Každé vlákno zvýší proměnnou ve while smyčce a spustí se pro nastavený čas.
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 volatile 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
K vláknu lze přiřadit jednu z následujících ThreadPriority hodnot priority:
HighestAboveNormalNormalBelowNormalLowest
Operační systémy nejsou vyžadovány pro respektování priority vlákna.