Thread.Join 方法

定义

在此实例表示的线程终止前,阻止调用线程。Blocks the calling thread until the thread represented by this instance terminates.

重载

Join()

在继续执行标准的 COM 和 SendMessage 消息泵处理期间,阻止调用线程,直到由该实例表示的线程终止。Blocks the calling thread until the thread represented by this instance terminates, while continuing to perform standard COM and SendMessage pumping.

Join(Int32)

在继续执行标准的 COM 和 SendMessage 消息泵处理期间,阻止调用线程,直到由该实例表示的线程终止或经过了指定时间为止。Blocks the calling thread until the thread represented by this instance terminates or the specified time elapses, while continuing to perform standard COM and SendMessage pumping.

Join(TimeSpan)

在继续执行标准的 COM 和 SendMessage 消息泵处理期间,阻止调用线程,直到由该实例表示的线程终止或经过了指定时间为止。Blocks the calling thread until the thread represented by this instance terminates or the specified time elapses, while continuing to perform standard COM and SendMessage pumping.

Join()

在继续执行标准的 COM 和 SendMessage 消息泵处理期间,阻止调用线程,直到由该实例表示的线程终止。Blocks the calling thread until the thread represented by this instance terminates, while continuing to perform standard COM and SendMessage pumping.

public:
 void Join();
public void Join ();
member this.Join : unit -> unit
Public Sub Join ()

异常

调用方尝试加入处于 Unstarted 状态的线程。The caller attempted to join a thread that is in the Unstarted state.

线程在等待时中断。The thread is interrupted while waiting.

注解

Join 是一种同步方法,用于阻止调用线程(即调用方法的线程),直到调用了 Join 方法的线程完成。Join is a synchronization method that blocks the calling thread (that is, the thread that calls the method) until the thread whose Join method is called has completed. 使用此方法可以确保线程已终止。Use this method to ensure that a thread has been terminated. 如果线程未终止,调用方将无限期阻止。The caller will block indefinitely if the thread does not terminate. 在下面的示例中,Thread1 线程调用 Thread2Join() 方法,这将导致 Thread1Thread2 完成之前一直阻止。In the following example, the Thread1 thread calls the Join() method of Thread2, which causes Thread1 to block until Thread2 has completed.

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
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

如果在调用 Join 时线程已终止,则该方法将立即返回。If the thread has already terminated when Join is called, the method returns immediately.

警告

绝不应从当前线程调用表示当前线程的 Thread 对象的 Join 方法。You should never call the Join method of the Thread object that represents the current thread from the current thread. 这会导致应用程序无响应,因为当前线程会无限期地等待,This causes your app to become unresponsive because the current thread waits upon itself indefinitely,

此方法更改调用线程的状态以包括 ThreadState.WaitSleepJoinThis method changes the state of the calling thread to include ThreadState.WaitSleepJoin. 不能对处于 ThreadState.Unstarted 状态的线程调用 JoinYou cannot invoke Join on a thread that is in the ThreadState.Unstarted state.

另请参阅

Join(Int32)

在继续执行标准的 COM 和 SendMessage 消息泵处理期间,阻止调用线程,直到由该实例表示的线程终止或经过了指定时间为止。Blocks the calling thread until the thread represented by this instance terminates or the specified time elapses, while continuing to perform standard COM and SendMessage pumping.

public:
 bool Join(int millisecondsTimeout);
public bool Join (int millisecondsTimeout);
member this.Join : int -> bool
Public Function Join (millisecondsTimeout As Integer) As Boolean

参数

millisecondsTimeout
Int32

等待线程终止的毫秒数。The number of milliseconds to wait for the thread to terminate.

返回

如果线程已终止,则为 true;如果 false 参数指定的时间量已过之后还未终止线程,则为 millisecondsTimeouttrue if the thread has terminated; false if the thread has not terminated after the amount of time specified by the millisecondsTimeout parameter has elapsed.

异常

millisecondsTimeout 的值为负数,且不等于 Infinite(以毫秒为单位)。The value of millisecondsTimeout is negative and is not equal to Infinite in milliseconds.

该线程尚未启动。The thread has not been started.

millisecondsTimeout 小于 -1 (Timeout.Infinite)。millisecondsTimeout is less than -1 (Timeout.Infinite).

线程在等待时中断。The thread was interrupted while waiting.

注解

Join(Int32) 是一种同步方法,该方法阻止调用线程(即调用方法的线程),直到调用了 Join 方法的线程已完成或超时间隔已过。Join(Int32) is a synchronization method that blocks the calling thread (that is, the thread that calls the method) until either the thread whose Join method is called has completed or the time-out interval has elapsed. 在下面的示例中,Thread1 线程调用 Thread2Join() 方法,这将导致 Thread1Thread2 完成之前或在2秒之前被阻止。In the following example, the Thread1 thread calls the Join() method of Thread2, which causes Thread1 to block either until Thread2 has completed or 2 seconds have elapsed.

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
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

如果为 millisecondsTimeout 参数指定了 Timeout.Infinite,则此方法的行为与 Join() 方法重载相同,返回值除外。If Timeout.Infinite is specified for the millisecondsTimeout parameter, this method behaves identically to the Join() method overload, except for the return value.

如果在调用 Join 时线程已终止,则该方法将立即返回。If the thread has already terminated when Join is called, the method returns immediately.

此方法更改调用线程的状态以包括 ThreadState.WaitSleepJoinThis method changes the state of the calling thread to include ThreadState.WaitSleepJoin. 不能对处于 ThreadState.Unstarted 状态的线程调用 JoinYou cannot invoke Join on a thread that is in the ThreadState.Unstarted state.

另请参阅

Join(TimeSpan)

在继续执行标准的 COM 和 SendMessage 消息泵处理期间,阻止调用线程,直到由该实例表示的线程终止或经过了指定时间为止。Blocks the calling thread until the thread represented by this instance terminates or the specified time elapses, while continuing to perform standard COM and SendMessage pumping.

public:
 bool Join(TimeSpan timeout);
public bool Join (TimeSpan timeout);
member this.Join : TimeSpan -> bool
Public Function Join (timeout As TimeSpan) As Boolean

参数

timeout
TimeSpan

设置等待线程终止的时间量的 TimeSpanA TimeSpan set to the amount of time to wait for the thread to terminate.

返回

如果线程已终止,则为 true;如果 false 参数指定的时间量已过之后还未终止线程,则为 timeouttrue if the thread terminated; false if the thread has not terminated after the amount of time specified by the timeout parameter has elapsed.

异常

timeout 的值为负数,且不等于 Infinite(以毫秒为单位),或大于 MaxValue 毫秒。The value of timeout is negative and is not equal to Infinite in milliseconds, or is greater than MaxValue milliseconds.

调用方尝试加入处于 Unstarted 状态的线程。The caller attempted to join a thread that is in the Unstarted state.

示例

下面的代码示例演示如何将 TimeSpan 值与 Join 方法一起使用。The following code example demonstrates how to use a TimeSpan value with the Join method.

using namespace System;
using namespace System::Threading;

static TimeSpan waitTime = TimeSpan(0,0,1);

ref class Test
{
public:
   static void Work()
   {
      Thread::Sleep( waitTime );
   }

};

int main()
{
   Thread^ newThread = gcnew Thread( gcnew ThreadStart( Test::Work ) );
   newThread->Start();
   if ( newThread->Join( waitTime + waitTime ) )
   {
      Console::WriteLine( "New thread terminated." );
   }
   else
   {
      Console::WriteLine( "Join timed out." );
   }
}
// The example displays the following output:
//        New thread terminated.
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.
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.

注解

Join(TimeSpan) 是一种同步方法,该方法阻止调用线程(即调用方法的线程),直到调用了 Join 方法的线程已完成或超时间隔已过。Join(TimeSpan) is a synchronization method that blocks the calling thread (that is, the thread that calls the method) until either the thread whose Join method is called has completed or the time-out interval has elapsed. 在下面的示例中,Thread1 线程调用 Thread2Join() 方法,这将导致 Thread1Thread2 完成之前或在2秒之前被阻止。In the following example, the Thread1 thread calls the Join() method of Thread2, which causes Thread1 to block either until Thread2 has completed or 2 seconds have elapsed.

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
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

如果为 timeout指定了 Timeout.Infinite,则此方法的行为与 Join() 方法重载相同,返回值除外。If Timeout.Infinite is specified for timeout, this method behaves identically to the Join() method overload, except for the return value.

如果在调用 Join 时线程已终止,则该方法将立即返回。If the thread has already terminated when Join is called, the method returns immediately.

此方法更改当前线程的状态以包括 WaitSleepJoinThis method changes the state of the current thread to include WaitSleepJoin. 不能对处于 ThreadState.Unstarted 状态的线程调用 JoinYou cannot invoke Join on a thread that is in the ThreadState.Unstarted state.

另请参阅

适用于