ManualResetEvent 类

定义

表示线程同步事件,收到信号时,必须手动重置该事件。Represents a thread synchronization event that, when signaled, must be reset manually. 无法继承此类。This class cannot be inherited.

public ref class ManualResetEvent sealed : System::Threading::EventWaitHandle
public sealed class ManualResetEvent : System.Threading.EventWaitHandle
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class ManualResetEvent : System.Threading.EventWaitHandle
type ManualResetEvent = class
    inherit EventWaitHandle
Public NotInheritable Class ManualResetEvent
Inherits EventWaitHandle
继承
ManualResetEvent
继承
继承
ManualResetEvent
属性

示例

下面的示例演示 ManualResetEvent 的工作方式。The following example demonstrates how ManualResetEvent works. 该示例以信号状态(即 false 传递给构造函数) ManualResetEvent 开头。The example starts with a ManualResetEvent in the unsignaled state (that is, false is passed to the constructor). 该示例创建三个线程,每个线程都通过调用其 WaitOne 方法在 ManualResetEvent 上阻塞。The example creates three threads, each of which blocks on the ManualResetEvent by calling its WaitOne method. 当用户按Enter键时,此示例将调用 Set 方法,该方法释放所有三个线程。When the user presses the Enter key, the example calls the Set method, which releases all three threads. 将此与 AutoResetEvent 类的行为进行对比,每次释放一个线程,并在每次发布后自动重置。Contrast this with the behavior of the AutoResetEvent class, which releases threads one at a time, resetting automatically after each release.

再次按下enter键会显示 ManualResetEvent 仍处于终止状态,直到调用其 Reset 方法为止:此示例将启动两个线程。Pressing the Enter key again demonstrates that the ManualResetEvent remains in the signaled state until its Reset method is called: The example starts two more threads. 这些线程在调用 WaitOne 方法时不会阻止,而是运行到完成。These threads do not block when they call the WaitOne method, but instead run to completion.

再次按enter键将导致该示例调用 Reset 方法,并启动一个线程,该线程在调用 WaitOne时被阻止。Pressing the Enter key again causes the example to call the Reset method and to start one more thread, which blocks when it calls WaitOne. enter键,最后一次调用 Set 释放最后一个线程,程序结束。Pressing the Enter key one final time calls Set to release the last thread, and the program ends.

using namespace System;
using namespace System::Threading;

ref class Example
{
private:
    // mre is used to block and release threads manually. It is
    // created in the unsignaled state.
    static ManualResetEvent^ mre = gcnew ManualResetEvent(false);

    static void ThreadProc()
    {
        String^ name = Thread::CurrentThread->Name;

        Console::WriteLine(name + " starts and calls mre->WaitOne()");

        mre->WaitOne();

        Console::WriteLine(name + " ends.");
    }

public:
    static void Demo()
    {
        Console::WriteLine("\nStart 3 named threads that block on a ManualResetEvent:\n");

        for(int i = 0; i <=2 ; i++)
        {
            Thread^ t = gcnew Thread(gcnew ThreadStart(ThreadProc));
            t->Name = "Thread_" + i;
            t->Start();
        }

        Thread::Sleep(500);
        Console::WriteLine("\nWhen all three threads have started, press Enter to call Set()" +
                           "\nto release all the threads.\n");
        Console::ReadLine();

        mre->Set();

        Thread::Sleep(500);
        Console::WriteLine("\nWhen a ManualResetEvent is signaled, threads that call WaitOne()" +
                           "\ndo not block. Press Enter to show this.\n");
        Console::ReadLine();

        for(int i = 3; i <= 4; i++)
        {
            Thread^ t = gcnew Thread(gcnew ThreadStart(ThreadProc));
            t->Name = "Thread_" + i;
            t->Start();
        }

        Thread::Sleep(500);
        Console::WriteLine("\nPress Enter to call Reset(), so that threads once again block" +
                           "\nwhen they call WaitOne().\n");
        Console::ReadLine();

        mre->Reset();

        // Start a thread that waits on the ManualResetEvent.
        Thread^ t5 = gcnew Thread(gcnew ThreadStart(ThreadProc));
        t5->Name = "Thread_5";
        t5->Start();

        Thread::Sleep(500);
        Console::WriteLine("\nPress Enter to call Set() and conclude the demo.");
        Console::ReadLine();

        mre->Set();

        // If you run this example in Visual Studio, uncomment the following line:
        //Console::ReadLine();
    }
};

int main()
{
   Example::Demo();
}

/* This example produces output similar to the following:

Start 3 named threads that block on a ManualResetEvent:

Thread_0 starts and calls mre->WaitOne()
Thread_1 starts and calls mre->WaitOne()
Thread_2 starts and calls mre->WaitOne()

When all three threads have started, press Enter to call Set()
to release all the threads.


Thread_2 ends.
Thread_1 ends.
Thread_0 ends.

When a ManualResetEvent is signaled, threads that call WaitOne()
do not block. Press Enter to show this.


Thread_3 starts and calls mre->WaitOne()
Thread_3 ends.
Thread_4 starts and calls mre->WaitOne()
Thread_4 ends.

Press Enter to call Reset(), so that threads once again block
when they call WaitOne().


Thread_5 starts and calls mre->WaitOne()

Press Enter to call Set() and conclude the demo.

Thread_5 ends.
 */
using System;
using System.Threading;

public class Example
{
    // mre is used to block and release threads manually. It is
    // created in the unsignaled state.
    private static ManualResetEvent mre = new ManualResetEvent(false);

    static void Main()
    {
        Console.WriteLine("\nStart 3 named threads that block on a ManualResetEvent:\n");

        for(int i = 0; i <= 2; i++)
        {
            Thread t = new Thread(ThreadProc);
            t.Name = "Thread_" + i;
            t.Start();
        }

        Thread.Sleep(500);
        Console.WriteLine("\nWhen all three threads have started, press Enter to call Set()" +
                          "\nto release all the threads.\n");
        Console.ReadLine();

        mre.Set();

        Thread.Sleep(500);
        Console.WriteLine("\nWhen a ManualResetEvent is signaled, threads that call WaitOne()" +
                          "\ndo not block. Press Enter to show this.\n");
        Console.ReadLine();

        for(int i = 3; i <= 4; i++)
        {
            Thread t = new Thread(ThreadProc);
            t.Name = "Thread_" + i;
            t.Start();
        }

        Thread.Sleep(500);
        Console.WriteLine("\nPress Enter to call Reset(), so that threads once again block" +
                          "\nwhen they call WaitOne().\n");
        Console.ReadLine();

        mre.Reset();

        // Start a thread that waits on the ManualResetEvent.
        Thread t5 = new Thread(ThreadProc);
        t5.Name = "Thread_5";
        t5.Start();

        Thread.Sleep(500);
        Console.WriteLine("\nPress Enter to call Set() and conclude the demo.");
        Console.ReadLine();

        mre.Set();

        // If you run this example in Visual Studio, uncomment the following line:
        //Console.ReadLine();
    }

    private static void ThreadProc()
    {
        string name = Thread.CurrentThread.Name;

        Console.WriteLine(name + " starts and calls mre.WaitOne()");

        mre.WaitOne();

        Console.WriteLine(name + " ends.");
    }
}

/* This example produces output similar to the following:

Start 3 named threads that block on a ManualResetEvent:

Thread_0 starts and calls mre.WaitOne()
Thread_1 starts and calls mre.WaitOne()
Thread_2 starts and calls mre.WaitOne()

When all three threads have started, press Enter to call Set()
to release all the threads.


Thread_2 ends.
Thread_0 ends.
Thread_1 ends.

When a ManualResetEvent is signaled, threads that call WaitOne()
do not block. Press Enter to show this.


Thread_3 starts and calls mre.WaitOne()
Thread_3 ends.
Thread_4 starts and calls mre.WaitOne()
Thread_4 ends.

Press Enter to call Reset(), so that threads once again block
when they call WaitOne().


Thread_5 starts and calls mre.WaitOne()

Press Enter to call Set() and conclude the demo.

Thread_5 ends.
 */
Imports System.Threading

Public Class Example

    ' mre is used to block and release threads manually. It is
    ' created in the unsignaled state.
    Private Shared mre As New ManualResetEvent(False)

    <MTAThreadAttribute> _
    Shared Sub Main()

        Console.WriteLine(vbLf & _
            "Start 3 named threads that block on a ManualResetEvent:" & vbLf)

        For i As Integer = 0 To 2
            Dim t As New Thread(AddressOf ThreadProc)
            t.Name = "Thread_" & i
            t.Start()
        Next i

        Thread.Sleep(500)
        Console.WriteLine(vbLf & _
            "When all three threads have started, press Enter to call Set()" & vbLf & _
            "to release all the threads." & vbLf)
        Console.ReadLine()

        mre.Set()

        Thread.Sleep(500)
        Console.WriteLine(vbLf & _
            "When a ManualResetEvent is signaled, threads that call WaitOne()" & vbLf & _
            "do not block. Press Enter to show this." & vbLf)
        Console.ReadLine()

        For i As Integer = 3 To 4
            Dim t As New Thread(AddressOf ThreadProc)
            t.Name = "Thread_" & i
            t.Start()
        Next i

        Thread.Sleep(500)
        Console.WriteLine(vbLf & _
            "Press Enter to call Reset(), so that threads once again block" & vbLf & _
            "when they call WaitOne()." & vbLf)
        Console.ReadLine()

        mre.Reset()

        ' Start a thread that waits on the ManualResetEvent.
        Dim t5 As New Thread(AddressOf ThreadProc)
        t5.Name = "Thread_5"
        t5.Start()

        Thread.Sleep(500)
        Console.WriteLine(vbLf & "Press Enter to call Set() and conclude the demo.")
        Console.ReadLine()

        mre.Set()

        ' If you run this example in Visual Studio, uncomment the following line:
        'Console.ReadLine()

    End Sub


    Private Shared Sub ThreadProc()

        Dim name As String = Thread.CurrentThread.Name

        Console.WriteLine(name & " starts and calls mre.WaitOne()")

        mre.WaitOne()

        Console.WriteLine(name & " ends.")

    End Sub

End Class

' This example produces output similar to the following:
'
'Start 3 named threads that block on a ManualResetEvent:
'
'Thread_0 starts and calls mre.WaitOne()
'Thread_1 starts and calls mre.WaitOne()
'Thread_2 starts and calls mre.WaitOne()
'
'When all three threads have started, press Enter to call Set()
'to release all the threads.
'
'
'Thread_2 ends.
'Thread_0 ends.
'Thread_1 ends.
'
'When a ManualResetEvent is signaled, threads that call WaitOne()
'do not block. Press Enter to show this.
'
'
'Thread_3 starts and calls mre.WaitOne()
'Thread_3 ends.
'Thread_4 starts and calls mre.WaitOne()
'Thread_4 ends.
'
'Press Enter to call Reset(), so that threads once again block
'when they call WaitOne().
'
'
'Thread_5 starts and calls mre.WaitOne()
'
'Press Enter to call Set() and conclude the demo.
'
'Thread_5 ends.

注解

你使用 ManualResetEventAutoResetEventEventWaitHandle 进行线程交互(或线程信号)。You use ManualResetEvent, AutoResetEvent, and EventWaitHandle for thread interaction (or thread signaling). 有关详细信息,请参阅同步基元概述一文中的 "线程交互" 或 "信号" 部分。For more information, see the Thread interaction, or signaling section of the Overview of synchronization primitives article.

当线程开始在其他线程继续之前必须完成的活动时,它将调用ManualResetEvent以将 ManualResetEvent 置于非终止状态。When a thread begins an activity that must complete before other threads proceed, it calls ManualResetEvent.Reset to put ManualResetEvent in the non-signaled state. 此线程可以被视为控制 ManualResetEventThis thread can be thought of as controlling the ManualResetEvent. 调用ManualResetEvent WaitOne的线程,等待信号。Threads that call ManualResetEvent.WaitOne block, awaiting the signal. 控制线程完成活动后,它将调用ManualResetEvent ,以指示等待线程可以继续。When the controlling thread completes the activity, it calls ManualResetEvent.Set to signal that the waiting threads can proceed. 所有等待线程都已释放。All waiting threads are released.

收到信号后,ManualResetEvent 会一直发出信号,直到通过调用 Reset() 方法进行手动重置。Once it has been signaled, ManualResetEvent remains signaled until it is manually reset by calling the Reset() method. 也就是说,对 WaitOne 的调用会立即返回。That is, calls to WaitOne return immediately.

你可以通过将布尔值传递到构造函数来控制 ManualResetEvent 的初始状态: true 如果初始状态为 "已终止",则为; 否则为 falseYou can control the initial state of a ManualResetEvent by passing a Boolean value to the constructor: true if the initial state is signaled, and false otherwise.

ManualResetEvent 还可以与 static WaitAllWaitAny 方法一起使用。ManualResetEvent can also be used with the static WaitAll and WaitAny methods.

从 .NET Framework 版本2.0 开始,ManualResetEventEventWaitHandle 类派生而来。Beginning with the .NET Framework version 2.0, ManualResetEvent derives from the EventWaitHandle class. ManualResetEvent 在功能上等效于使用 EventResetMode.ManualReset创建的 EventWaitHandleA ManualResetEvent is functionally equivalent to an EventWaitHandle created with EventResetMode.ManualReset.

备注

ManualResetEvent 类不同,EventWaitHandle 类提供对已命名的系统同步事件的访问。Unlike the ManualResetEvent class, the EventWaitHandle class provides access to named system synchronization events.

从 .NET Framework 版本4.0 开始,System.Threading.ManualResetEventSlim 类是 ManualResetEvent的轻型替代项。Beginning with the .NET Framework version 4.0, the System.Threading.ManualResetEventSlim class is a lightweight alternative to ManualResetEvent.

构造函数

ManualResetEvent(Boolean)

用一个指示是否将初始状态设置为终止的布尔值初始化 ManualResetEvent 类的新实例。Initializes a new instance of the ManualResetEvent class with a Boolean value indicating whether to set the initial state to signaled.

字段

WaitTimeout

指示在任何等待句柄终止之前 WaitAny(WaitHandle[], Int32, Boolean) 操作已超时。Indicates that a WaitAny(WaitHandle[], Int32, Boolean) operation timed out before any of the wait handles were signaled. 此字段为常数。This field is constant.

(继承自 WaitHandle)

属性

Handle

获取或设置本机操作系统句柄。Gets or sets the native operating system handle.

(继承自 WaitHandle)
SafeWaitHandle

获取或设置本机操作系统句柄。Gets or sets the native operating system handle.

(继承自 WaitHandle)

方法

Close()

释放由当前 WaitHandle 占用的所有资源。Releases all resources held by the current WaitHandle.

(继承自 WaitHandle)
CreateObjRef(Type)

创建一个对象,该对象包含生成用于与远程对象进行通信的代理所需的全部相关信息。Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object.

(继承自 MarshalByRefObject)
Dispose()

释放 WaitHandle 类的当前实例所使用的所有资源。Releases all resources used by the current instance of the WaitHandle class.

(继承自 WaitHandle)
Dispose(Boolean)

当在派生类中重写时,释放 WaitHandle 使用的非托管资源,并且可选择释放托管资源。When overridden in a derived class, releases the unmanaged resources used by the WaitHandle, and optionally releases the managed resources.

(继承自 WaitHandle)
Equals(Object)

确定指定对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetAccessControl()

获取一个 EventWaitHandleSecurity 对象,它表示当前 EventWaitHandle 对象所表示的已命名系统事件的访问控件安全性。Gets an EventWaitHandleSecurity object that represents the access control security for the named system event represented by the current EventWaitHandle object.

(继承自 EventWaitHandle)
GetHashCode()

用作默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetLifetimeService()

检索控制此实例的生存期策略的当前生存期服务对象。Retrieves the current lifetime service object that controls the lifetime policy for this instance.

(继承自 MarshalByRefObject)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
InitializeLifetimeService()

获取生存期服务对象来控制此实例的生存期策略。Obtains a lifetime service object to control the lifetime policy for this instance.

(继承自 MarshalByRefObject)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
MemberwiseClone(Boolean)

创建当前 MarshalByRefObject 对象的浅表副本。Creates a shallow copy of the current MarshalByRefObject object.

(继承自 MarshalByRefObject)
Reset()

将事件状态设置为非终止,从而导致线程受阻。Sets the state of the event to nonsignaled, which causes threads to block.

Set()

将事件状态设置为终止状态,从而允许继续执行一个或多个等待线程。Sets the state of the event to signaled, which allows one or more waiting threads to proceed.

SetAccessControl(EventWaitHandleSecurity)

设置已命名的系统事件的访问控制安全性。Sets the access control security for a named system event.

(继承自 EventWaitHandle)
ToString()

返回表示当前对象的字符串。Returns a string that represents the current object.

(继承自 Object)
WaitOne()

阻止当前线程,直到当前 WaitHandle 收到信号。Blocks the current thread until the current WaitHandle receives a signal.

(继承自 WaitHandle)
WaitOne(Int32)

阻止当前线程,直到当前 WaitHandle 收到信号,同时使用 32 位带符号整数指定时间间隔(以毫秒为单位)。Blocks the current thread until the current WaitHandle receives a signal, using a 32-bit signed integer to specify the time interval in milliseconds.

(继承自 WaitHandle)
WaitOne(Int32, Boolean)

阻止当前线程,直到当前的 WaitHandle 收到信号为止,同时使用 32 位带符号整数指定时间间隔,并指定是否在等待之前退出同步域。Blocks the current thread until the current WaitHandle receives a signal, using a 32-bit signed integer to specify the time interval and specifying whether to exit the synchronization domain before the wait.

(继承自 WaitHandle)
WaitOne(TimeSpan)

阻止当前线程,直到当前实例收到信号,同时使用 TimeSpan 指定时间间隔。Blocks the current thread until the current instance receives a signal, using a TimeSpan to specify the time interval.

(继承自 WaitHandle)
WaitOne(TimeSpan, Boolean)

阻止当前线程,直到当前实例收到信号为止,同时使用 TimeSpan 指定时间间隔,并指定是否在等待之前退出同步域。Blocks the current thread until the current instance receives a signal, using a TimeSpan to specify the time interval and specifying whether to exit the synchronization domain before the wait.

(继承自 WaitHandle)

显式接口实现

IDisposable.Dispose()

释放 WaitHandle 使用的所有资源。Releases all resources used by the WaitHandle.

(继承自 WaitHandle)

扩展方法

GetAccessControl(EventWaitHandle)
SetAccessControl(EventWaitHandle, EventWaitHandleSecurity)
GetSafeWaitHandle(WaitHandle)

获取本机操作系统等待句柄的安全句柄。Gets the safe handle for a native operating system wait handle.

SetSafeWaitHandle(WaitHandle, SafeWaitHandle)

设置本机操作系统等待句柄的安全句柄。Sets a safe handle for a native operating system wait handle.

适用于

线程安全性

此类是线程安全的。This class is thread safe.

另请参阅