Thread.Join 方法

定義

命名空間:: System.Threading

組件:: netstandard.dll, System.Threading.Thread.dll

組件:: System.Threading.Thread.dll

組件:: mscorlib.dll

組件:: netstandard.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

阻塞呼叫執行緒，直到該執行緒終止。

多載

名稱	Description
Join()	阻塞呼叫執行緒，直到該執行緒終止，同時繼續執行標準 COM 與 `SendMessage` 抽取。
Join(Int32)	在執行標準 COM 與 SendMessage 泵送前，阻塞呼叫執行緒直到該執行緒終止或指定時間結束。
Join(TimeSpan)	在執行標準 COM 與 SendMessage 泵送前，阻塞呼叫執行緒直到該執行緒終止或指定時間結束。

Join()

來源:: Thread.cs

來源:: Thread.cs

來源:: Thread.cs

來源:: Thread.cs

來源:: Thread.cs

阻塞呼叫執行緒，直到該執行緒終止，同時繼續執行標準 COM 與 SendMessage 抽取。

public:
 void Join();

public void Join();

member this.Join : unit -> unit

Public Sub Join ()

例外狀況

ThreadStateException

來電者嘗試加入該 Unstarted 州的一個討論串。

ThreadInterruptedException

等待時執行緒被中斷。

備註

Join 是一種同步方法，會阻擋呼叫執行緒（即呼叫該方法的執行緒），直到被呼叫的方法 Join 執行緒完成為止。使用此方法確保執行緒已被終止。如果執行緒沒有終止，呼叫者將無限期封鎖。以下範例中， Thread1 執行緒呼叫 Join() 的方法 Thread2，導致 Thread1 阻塞直到 Thread2 完成。

using System;
using System.Threading;

public class Example
{
   static Thread thread1, thread2;
   
   public static void Main()
   {
      thread1 = new Thread(ThreadProc);
      thread1.Name = "Thread1";
      thread1.Start();
      
      thread2 = new Thread(ThreadProc);
      thread2.Name = "Thread2";
      thread2.Start();   
   }

   private static void ThreadProc()
   {
      Console.WriteLine("\nCurrent thread: {0}", Thread.CurrentThread.Name);
      if (Thread.CurrentThread.Name == "Thread1" && 
          thread2.ThreadState != ThreadState.Unstarted)
         thread2.Join();
      
      Thread.Sleep(4000);
      Console.WriteLine("\nCurrent thread: {0}", Thread.CurrentThread.Name);
      Console.WriteLine("Thread1: {0}", thread1.ThreadState);
      Console.WriteLine("Thread2: {0}\n", thread2.ThreadState);
   }
}
// The example displays output like the following:
//       Current thread: Thread1
//       
//       Current thread: Thread2
//       
//       Current thread: Thread2
//       Thread1: WaitSleepJoin
//       Thread2: Running
//       
//       
//       Current thread: Thread1
//       Thread1: Running
//       Thread2: Stopped

open System.Threading

let mutable thread1, thread2 =
    Unchecked.defaultof<Thread>, Unchecked.defaultof<Thread>

let threadProc () =
    printfn $"\nCurrent thread: {Thread.CurrentThread.Name}"

    if
        Thread.CurrentThread.Name = "Thread1"
        && thread2.ThreadState <> ThreadState.Unstarted
    then
        thread2.Join()

    Thread.Sleep 4000
    printfn $"\nCurrent thread: {Thread.CurrentThread.Name}"
    printfn $"Thread1: {thread1.ThreadState}"
    printfn $"Thread2: {thread2.ThreadState}\n"

thread1 <- Thread threadProc
thread1.Name <- "Thread1"
thread1.Start()

thread2 <- Thread threadProc
thread2.Name <- "Thread2"
thread2.Start()

// The example displays output like the following:
//       Current thread: Thread1
//
//       Current thread: Thread2
//
//       Current thread: Thread2
//       Thread1: WaitSleepJoin
//       Thread2: Running
//
//
//       Current thread: Thread1
//       Thread1: Running
//       Thread2: Stopped

Imports System.Threading

Module Example
   Dim thread1, thread2 As Thread

   Public Sub Main()
      thread1 = new Thread(AddressOf ThreadProc)
      thread1.Name = "Thread1"
      thread1.Start()
      
      thread2 = New Thread(AddressOf ThreadProc)
      thread2.Name = "Thread2"
      thread2.Start()   
   End Sub

   Private Sub ThreadProc()
      Console.WriteLine()
      Console.WriteLine("Current thread: {0}", Thread.CurrentThread.Name)
      If (Thread.CurrentThread.Name = "Thread1" And 
          thread2.ThreadState <> ThreadState.Unstarted)
         thread2.Join()
      End If
      Thread.Sleep(4000)
      Console.WriteLine()
      Console.WriteLine("Current thread: {0}", Thread.CurrentThread.Name)
      Console.WriteLine("Thread1: {0}", thread1.ThreadState)
      Console.WriteLine("Thread2: {0}", thread2.ThreadState)
      Console.WriteLine()
   End Sub
End Module
' The example displays output like the following :
'       Current thread: Thread1
'       
'       Current thread: Thread2
'       
'       Current thread: Thread2
'       Thread1: WaitSleepJoin
'       Thread2: Running
'       
'       
'       Current thread: Thread1
'       Thread1: Running
'       Thread2: Stopped

如果呼叫時 Join 執行緒已經終止，方法會立即回傳。

警告

你絕對不應該從目前執行緒呼叫 Join 代表當前執行緒的物件的方法 Thread 。這會導致你的應用程式失去回應，因為當前執行緒無限期地等待自己，

此方法將呼叫執行緒的狀態變更為包含 ThreadState.WaitSleepJoin。你不能在該Join州的執行緒上調ThreadState.Unstarted用。

另請參閱

ThreadState

適用於

Join(Int32)

來源:: Thread.CoreCLR.cs

來源:: Thread.cs

來源:: Thread.cs

來源:: Thread.cs

來源:: Thread.cs

在執行標準 COM 與 SendMessage 泵送前，阻塞呼叫執行緒直到該執行緒終止或指定時間結束。

public:
 bool Join(int millisecondsTimeout);

public bool Join(int millisecondsTimeout);

member this.Join : int -> bool

Public Function Join (millisecondsTimeout As Integer) As Boolean

參數

millisecondsTimeout: Int32

等待執行緒終止所需的毫秒數。

傳回

Boolean

true 如果執行緒已經終止; false 如果執行緒在參數指定 millisecondsTimeout 時間內仍未終止。

例外狀況

ArgumentOutOfRangeException

的 millisecondsTimeout 值為負值，且不等 Infinite 於毫秒。

ThreadStateException

該討論串尚未啟動。

ArgumentException

millisecondsTimeout 小於 -1（Timeout.Infinite）。

ThreadInterruptedException

等待時，討論串被打斷了。

備註

Join(Int32) 是一種同步方法，會阻擋呼叫執行緒（即呼叫該方法的執行緒），直到被呼叫的方法執行緒 Join 完成或逾時間隔結束為止。在以下範例中， Thread1 執行緒呼叫 Join() 的方法 Thread2，導致 Thread1 阻塞直到 Thread2 完成或 2 秒後。

using System;
using System.Threading;

public class Example
{
   static Thread thread1, thread2;
   
   public static void Main()
   {
      thread1 = new Thread(ThreadProc);
      thread1.Name = "Thread1";
      thread1.Start();
      
      thread2 = new Thread(ThreadProc);
      thread2.Name = "Thread2";
      thread2.Start();   
   }

   private static void ThreadProc()
   {
      Console.WriteLine("\nCurrent thread: {0}", Thread.CurrentThread.Name);
      if (Thread.CurrentThread.Name == "Thread1" && 
          thread2.ThreadState != ThreadState.Unstarted)
         if (thread2.Join(2000))
            Console.WriteLine("Thread2 has termminated.");
         else
            Console.WriteLine("The timeout has elapsed and Thread1 will resume.");   
      
      Thread.Sleep(4000);
      Console.WriteLine("\nCurrent thread: {0}", Thread.CurrentThread.Name);
      Console.WriteLine("Thread1: {0}", thread1.ThreadState);
      Console.WriteLine("Thread2: {0}\n", thread2.ThreadState);
   }
}
// The example displays the following output:
//       Current thread: Thread1
//       
//       Current thread: Thread2
//       The timeout has elapsed and Thread1 will resume.
//       
//       Current thread: Thread2
//       Thread1: WaitSleepJoin
//       Thread2: Running
//       
//       
//       Current thread: Thread1
//       Thread1: Running
//       Thread2: Stopped

open System.Threading

let mutable thread1, thread2 =
    Unchecked.defaultof<Thread>, Unchecked.defaultof<Thread>

let threadProc () =
    printfn $"\nCurrent thread: {Thread.CurrentThread.Name}"

    if
        Thread.CurrentThread.Name = "Thread1"
        && thread2.ThreadState <> ThreadState.Unstarted
    then
        if thread2.Join 2000 then
            printfn "Thread2 has termminated."
        else
            printfn "The timeout has elapsed and Thread1 will resume."

    Thread.Sleep 4000
    printfn $"\nCurrent thread: {Thread.CurrentThread.Name}"
    printfn $"Thread1: {thread1.ThreadState}"
    printfn $"Thread2: {thread2.ThreadState}\n"

thread1 <- Thread threadProc
thread1.Name <- "Thread1"
thread1.Start()

thread2 <- Thread threadProc
thread2.Name <- "Thread2"
thread2.Start()

// The example displays the following output:
//       Current thread: Thread1
//
//       Current thread: Thread2
//       The timeout has elapsed and Thread1 will resume.
//
//       Current thread: Thread2
//       Thread1: WaitSleepJoin
//       Thread2: Running
//
//
//       Current thread: Thread1
//       Thread1: Running
//       Thread2: Stopped

Imports System.Threading

Module Example
   Dim thread1, thread2 As Thread

   Public Sub Main()
      thread1 = new Thread(AddressOf ThreadProc)
      thread1.Name = "Thread1"
      thread1.Start()
      
      thread2 = New Thread(AddressOf ThreadProc)
      thread2.Name = "Thread2"
      thread2.Start()   
   End Sub

   Private Sub ThreadProc()
      Console.WriteLine()
      Console.WriteLine("Current thread: {0}", Thread.CurrentThread.Name)
      If (Thread.CurrentThread.Name = "Thread1" And 
          thread2.ThreadState <> ThreadState.Unstarted)
         If thread2.Join(TimeSpan.FromSeconds(2))
            Console.WriteLine("Thread2 has termminated.")
         Else
            Console.WriteLine("The timeout has elapsed and Thread1 will resume.")
         End If      
      End If
      Thread.Sleep(4000)
      Console.WriteLine()
      Console.WriteLine("Current thread: {0}", Thread.CurrentThread.Name)
      Console.WriteLine("Thread1: {0}", thread1.ThreadState)
      Console.WriteLine("Thread2: {0}", thread2.ThreadState)
      Console.WriteLine()
   End Sub
End Module
' The example displays the following output:
'       Current thread: Thread1
'       
'       Current thread: Thread2
'       
'       Current thread: Thread2
'       Thread1: WaitSleepJoin
'       Thread2: Running
'       
'       
'       Current thread: Thread1
'       Thread1: Running
'       Thread2: Stopped

若 Timeout.Infinite 參數指定 millisecondsTimeout ，該方法的行為與方法過載相同 Join() ，唯獨回傳值不同。

如果呼叫時 Join 執行緒已經終止，方法會立即回傳。

此方法將呼叫執行緒的狀態變更為包含 ThreadState.WaitSleepJoin。你不能在該Join州的執行緒上調ThreadState.Unstarted用。

另請參閱

ThreadState

適用於

Join(TimeSpan)

來源:: Thread.cs

來源:: Thread.cs

來源:: Thread.cs

來源:: Thread.cs

來源:: Thread.cs

在執行標準 COM 與 SendMessage 泵送前，阻塞呼叫執行緒直到該執行緒終止或指定時間結束。

public:
 bool Join(TimeSpan timeout);

public bool Join(TimeSpan timeout);

member this.Join : TimeSpan -> bool

Public Function Join (timeout As TimeSpan) As Boolean

參數

timeout: TimeSpan

A TimeSpan 是等待執行緒終止的時間。

傳回

Boolean

true 如果執行緒終止; false 如果執行緒在參數指定 timeout 時間內仍未終止。

例外狀況

ArgumentOutOfRangeException

的 timeout 值為負值，且不等 Infinite 於毫秒，也不會大於 Int32.MaxValue 毫秒。

ThreadStateException

來電者嘗試加入該 Unstarted 州的一個討論串。

範例

以下程式碼範例示範如何使用 TimeSpan 該方法的 Join 值。

using System;
using System.Threading;

class Test
{
    static TimeSpan waitTime = new TimeSpan(0, 0, 1);

    public static void Main() 
    {
        Thread newThread = new Thread(Work);
        newThread.Start();

        if(newThread.Join(waitTime + waitTime)) {
            Console.WriteLine("New thread terminated.");
        }
        else {
            Console.WriteLine("Join timed out.");
        }
    }

    static void Work()
    {
        Thread.Sleep(waitTime);
    }
}
// The example displays the following output:
//        New thread terminated.

open System
open System.Threading

let waitTime = TimeSpan(0, 0, 1)

let work () =
    Thread.Sleep waitTime

let newThread = Thread work
newThread.Start()

if waitTime + waitTime |> newThread.Join then
    printfn "New thread terminated."
else
    printfn "Join timed out."

// The example displays the following output:
//        New thread terminated.

Imports System.Threading

Public Module Test
    Dim waitTime As New TimeSpan(0, 0, 1)

    Public Sub Main() 
        Dim newThread As New Thread(AddressOf Work)
        newThread.Start()

        If newThread.Join(waitTime + waitTime) Then
            Console.WriteLine("New thread terminated.")
        Else
            Console.WriteLine("Join timed out.")
        End If
    End Sub

    Private Sub Work()
        Thread.Sleep(waitTime)
    End Sub
End Module
' The example displays the following output:
'       New thread terminated.

備註

Join(TimeSpan) 是一種同步方法，會阻擋呼叫執行緒（即呼叫該方法的執行緒），直到被呼叫的方法執行緒 Join 完成或逾時間隔結束為止。在以下範例中， Thread1 執行緒呼叫 Join() 的方法 Thread2，導致 Thread1 阻塞直到 Thread2 完成或 2 秒後。

using System;
using System.Threading;

public class Example
{
   static Thread thread1, thread2;
   
   public static void Main()
   {
      thread1 = new Thread(ThreadProc);
      thread1.Name = "Thread1";
      thread1.Start();
      
      thread2 = new Thread(ThreadProc);
      thread2.Name = "Thread2";
      thread2.Start();   
   }

   private static void ThreadProc()
   {
      Console.WriteLine("\nCurrent thread: {0}", Thread.CurrentThread.Name);
      if (Thread.CurrentThread.Name == "Thread1" && 
          thread2.ThreadState != ThreadState.Unstarted)
         if (thread2.Join(TimeSpan.FromSeconds(2)))
            Console.WriteLine("Thread2 has termminated.");
         else
            Console.WriteLine("The timeout has elapsed and Thread1 will resume.");   
      
      Thread.Sleep(4000);
      Console.WriteLine("\nCurrent thread: {0}", Thread.CurrentThread.Name);
      Console.WriteLine("Thread1: {0}", thread1.ThreadState);
      Console.WriteLine("Thread2: {0}\n", thread2.ThreadState);
   }
}
// The example displays the following output:
//       Current thread: Thread1
//       
//       Current thread: Thread2
//       The timeout has elapsed and Thread1 will resume.
//       
//       Current thread: Thread2
//       Thread1: WaitSleepJoin
//       Thread2: Running
//       
//       
//       Current thread: Thread1
//       Thread1: Running
//       Thread2: Stopped

open System
open System.Threading

let mutable thread1, thread2 =
    Unchecked.defaultof<Thread>, Unchecked.defaultof<Thread>

let threadProc () =
    printfn $"\nCurrent thread: {Thread.CurrentThread.Name}"

    if
        Thread.CurrentThread.Name = "Thread1"
        && thread2.ThreadState <> ThreadState.Unstarted
    then
        if TimeSpan.FromSeconds 2 |> thread2.Join then
            printfn "Thread2 has termminated."
        else
            printfn "The timeout has elapsed and Thread1 will resume."

    Thread.Sleep 4000
    printfn $"\nCurrent thread: {Thread.CurrentThread.Name}"
    printfn $"Thread1: {thread1.ThreadState}"
    printfn $"Thread2: {thread2.ThreadState}\n"

thread1 <- Thread threadProc
thread1.Name <- "Thread1"
thread1.Start()

thread2 <- Thread threadProc
thread2.Name <- "Thread2"
thread2.Start()

// The example displays the following output:
//       Current thread: Thread1
//
//       Current thread: Thread2
//       The timeout has elapsed and Thread1 will resume.
//
//       Current thread: Thread2
//       Thread1: WaitSleepJoin
//       Thread2: Running
//
//
//       Current thread: Thread1
//       Thread1: Running
//       Thread2: Stopped

Imports System.Threading

Module Example
   Dim thread1, thread2 As Thread

   Public Sub Main()
      thread1 = new Thread(AddressOf ThreadProc)
      thread1.Name = "Thread1"
      thread1.Start()
      
      thread2 = New Thread(AddressOf ThreadProc)
      thread2.Name = "Thread2"
      thread2.Start()   
   End Sub

   Private Sub ThreadProc()
      Console.WriteLine()
      Console.WriteLine("Current thread: {0}", Thread.CurrentThread.Name)
      If (Thread.CurrentThread.Name = "Thread1" And 
          thread2.ThreadState <> ThreadState.Unstarted)
         If thread2.Join(2000)
            Console.WriteLine("Thread2 has termminated.")
         Else
            Console.WriteLine("The timeout has elapsed and Thread1 will resume.")
         End If      
      End If
      Thread.Sleep(4000)
      Console.WriteLine()
      Console.WriteLine("Current thread: {0}", Thread.CurrentThread.Name)
      Console.WriteLine("Thread1: {0}", thread1.ThreadState)
      Console.WriteLine("Thread2: {0}", thread2.ThreadState)
      Console.WriteLine()
   End Sub
End Module
' The example displays the following output:
'       Current thread: Thread1
'       
'       Current thread: Thread2
'       
'       Current thread: Thread2
'       Thread1: WaitSleepJoin
'       Thread2: Running
'       
'       
'       Current thread: Thread1
'       Thread1: Running
'       Thread2: Stopped

若 Timeout.Infinite 指定為 timeout，此方法的行為與方法過載相同 Join() ，唯獨返回值不同。

如果呼叫時 Join 執行緒已經終止，方法會立即回傳。

此方法會將當前執行緒的狀態變更為包含 WaitSleepJoin。你不能在該Join州的執行緒上調ThreadState.Unstarted用。

另請參閱

ThreadState

適用於

意見反應

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