SafeWaitHandle 类

定义

表示 wait 句柄的包装类。Represents a wrapper class for a wait handle.

public ref class SafeWaitHandle sealed : System::Runtime::InteropServices::SafeHandle
public ref class SafeWaitHandle sealed : Microsoft::Win32::SafeHandles::SafeHandleZeroOrMinusOneIsInvalid
[System.Security.SecurityCritical]
public sealed class SafeWaitHandle : System.Runtime.InteropServices.SafeHandle
public sealed class SafeWaitHandle : Microsoft.Win32.SafeHandles.SafeHandleZeroOrMinusOneIsInvalid
[System.Security.SecurityCritical]
public sealed class SafeWaitHandle : Microsoft.Win32.SafeHandles.SafeHandleZeroOrMinusOneIsInvalid
[<System.Security.SecurityCritical>]
type SafeWaitHandle = class
    inherit SafeHandle
type SafeWaitHandle = class
    inherit SafeHandleZeroOrMinusOneIsInvalid
[<System.Security.SecurityCritical>]
type SafeWaitHandle = class
    inherit SafeHandleZeroOrMinusOneIsInvalid
Public NotInheritable Class SafeWaitHandle
Inherits SafeHandle
Public NotInheritable Class SafeWaitHandle
Inherits SafeHandleZeroOrMinusOneIsInvalid
继承
SafeWaitHandle
继承
属性

示例

下面的代码示例演示如何使用 SafeWaitHandle 类和非托管函数来创建互斥体 CreateMutexThe following code example demonstrates how to use interop to create a mutex using the SafeWaitHandle class and the unmanaged CreateMutex function.

using System;
using Microsoft.Win32.SafeHandles;
using System.Runtime.InteropServices;

class SafeHandlesExample
{

    static void Main()
    {
        UnmanagedMutex uMutex = new UnmanagedMutex("YourCompanyName_SafeHandlesExample_MUTEX");

        try
        {

            uMutex.Create();
            Console.WriteLine("Mutex created. Press Enter to release it.");
            Console.ReadLine();
        }
        catch (Exception e)
        {
            Console.WriteLine(e);
        }
        finally
        {
            uMutex.Release();
            Console.WriteLine("Mutex Released.");
        }

        Console.ReadLine();
    }
}

class UnmanagedMutex
{

    // Use interop to call the CreateMutex function.
    // For more information about CreateMutex,
    // see the unmanaged MSDN reference library.
    [DllImport("kernel32.dll", CharSet=CharSet.Unicode)]
    static extern SafeWaitHandle CreateMutex(IntPtr lpMutexAttributes, bool bInitialOwner,
    string lpName);

    // Use interop to call the ReleaseMutex function.
    // For more information about ReleaseMutex,
    // see the unmanaged MSDN reference library.
    [DllImport("kernel32.dll")]
    public static extern bool ReleaseMutex(SafeWaitHandle hMutex);

    private SafeWaitHandle handleValue = null;
    private IntPtr mutexAttrValue = IntPtr.Zero;
    private string nameValue = null;

    public UnmanagedMutex(string Name)
    {
        nameValue = Name;
    }

    public void Create()
    {
        if (nameValue == null && nameValue.Length == 0)
        {
            throw new ArgumentNullException("nameValue");
        }

        handleValue = CreateMutex(mutexAttrValue,
                                        true, nameValue);

        // If the handle is invalid,
        // get the last Win32 error
        // and throw a Win32Exception.
        if (handleValue.IsInvalid)
        {
            Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
        }
    }

    public SafeWaitHandle Handle
    {
        get
        {
            // If the handle is valid,
            // return it.
            if (!handleValue.IsInvalid)
            {
                return handleValue;
            }
            else
            {
                return null;
            }
        }
    }

    public string Name
    {
        get
        {
            return nameValue;
        }
    }

    public void Release()
    {
        ReleaseMutex(handleValue);
    }
}
Imports Microsoft.Win32.SafeHandles
Imports System.Runtime.InteropServices

Class SafeHandlesExample


    Shared Sub Main()
        Dim uMutex As New UnmanagedMutex("YourCompanyName_SafeHandlesExample_MUTEX")

        Try

            uMutex.Create()
            Console.WriteLine("Mutex created. Press Enter to release it.")
            Console.ReadLine()


        Catch e As Exception
            Console.WriteLine(e)
        Finally
            uMutex.Release()
            Console.WriteLine("Mutex Released.")
        End Try

        Console.ReadLine()

    End Sub
End Class


Class UnmanagedMutex



    ' Use interop to call the CreateMutex function.
    ' For more information about CreateMutex,
    ' see the unmanaged MSDN reference library.
    <DllImport("kernel32.dll", CharSet:=CharSet.Unicode)> _
    Shared Function CreateMutex(ByVal lpMutexAttributes As IntPtr, ByVal bInitialOwner As Boolean, ByVal lpName As String) As SafeWaitHandle

    End Function



    ' Use interop to call the ReleaseMutex function.
    ' For more information about ReleaseMutex,
    ' see the unmanaged MSDN reference library.
    <DllImport("kernel32.dll")> _
    Public Shared Function ReleaseMutex(ByVal hMutex As SafeWaitHandle) As Boolean

    End Function



    Private handleValue As SafeWaitHandle = Nothing
    Private mutexAttrValue As IntPtr = IntPtr.Zero
    Private nameValue As String = Nothing


    Public Sub New(ByVal Name As String)
        nameValue = Name

    End Sub



    Public Sub Create()
        If nameValue Is Nothing AndAlso nameValue.Length = 0 Then
            Throw New ArgumentNullException("nameValue")
        End If

        handleValue = CreateMutex(mutexAttrValue, True, nameValue)

        ' If the handle is invalid,
        ' get the last Win32 error 
        ' and throw a Win32Exception.
        If handleValue.IsInvalid Then
            Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error())
        End If

    End Sub


    Public ReadOnly Property Handle() As SafeWaitHandle
        Get
            ' If the handle is valid,
            ' return it.
            If Not handleValue.IsInvalid Then
                Return handleValue
            Else
                Return Nothing
            End If
        End Get
    End Property


    Public ReadOnly Property Name() As String
        Get
            Return nameValue
        End Get
    End Property



    Public Sub Release()
        ReleaseMutex(handleValue)

    End Sub
End Class

注解

类由 SafeWaitHandle System.Threading.WaitHandle 类使用。The SafeWaitHandle class is used by the System.Threading.WaitHandle class. 它是 Win32 互斥体和自动和手动重置事件的包装。It is a wrapper for Win32 mutexes and auto and manual reset events.

重要

此类型实现 IDisposable 接口。This type implements the IDisposable interface. 在使用完类型后,您应直接或间接释放类型。When you have finished using the type, you should dispose of it either directly or indirectly. 若要直接释放类型,请在 try/catch 块中调用其 Dispose 方法。To dispose of the type directly, call its Dispose method in a try/catch block. 若要间接释放类型,请使用 using(在 C# 中)或 Using(在 Visual Basic 中)等语言构造。To dispose of it indirectly, use a language construct such as using (in C#) or Using (in Visual Basic). 有关详细信息,请参阅 IDisposable 接口主题中的“使用实现 IDisposable 的对象”一节。For more information, see the "Using an Object that Implements IDisposable" section in the IDisposable interface topic.

构造函数

SafeWaitHandle(IntPtr, Boolean)

初始化 SafeWaitHandle 类的新实例。Initializes a new instance of the SafeWaitHandle class.

字段

handle

指定要包装的句柄。Specifies the handle to be wrapped.

(继承自 SafeHandle)

属性

IsClosed

获取一个值,该值指示句柄是否已关闭。Gets a value indicating whether the handle is closed.

(继承自 SafeHandle)
IsInvalid

获取一个值,该值指示句柄是否无效。Gets a value that indicates whether the handle is invalid.

IsInvalid

在派生类中重写时,获取一个值,该值指示句柄值是否无效。When overridden in a derived class, gets a value indicating whether the handle value is invalid.

(继承自 SafeHandle)
IsInvalid

获取一个值,该值指示句柄是否无效。Gets a value that indicates whether the handle is invalid.

(继承自 SafeHandleZeroOrMinusOneIsInvalid)

方法

Close()

标记句柄,以便释放资源。Marks the handle for releasing and freeing resources.

(继承自 SafeHandle)
DangerousAddRef(Boolean)

手动递增 SafeHandle 实例中的引用计数器。Manually increments the reference counter on SafeHandle instances.

(继承自 SafeHandle)
DangerousGetHandle()

返回 handle 字段的值。Returns the value of the handle field.

(继承自 SafeHandle)
DangerousRelease()

手动递减 SafeHandle 实例中的引用计数器。Manually decrements the reference counter on a SafeHandle instance.

(继承自 SafeHandle)
Dispose()

释放 SafeHandle 类使用的所有资源。Releases all resources used by the SafeHandle class.

(继承自 SafeHandle)
Dispose(Boolean)

释放 SafeHandle 类所使用的非托管资源,指定是否执行常规释放操作。Releases the unmanaged resources used by the SafeHandle class specifying whether to perform a normal dispose operation.

(继承自 SafeHandle)
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)
GetHashCode()

作为默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetType()

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

(继承自 Object)
MemberwiseClone()

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

(继承自 Object)
ReleaseHandle()

在派生类中重写时,执行释放句柄所需的代码。When overridden in a derived class, executes the code required to free the handle.

(继承自 SafeHandle)
SetHandle(IntPtr)

将句柄设置为预先存在的指定句柄。Sets the handle to the specified pre-existing handle.

(继承自 SafeHandle)
SetHandleAsInvalid()

将句柄标记为不再使用。Marks a handle as no longer used.

(继承自 SafeHandle)
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)

适用于

另请参阅