MessageQueue.Close 方法

参考

定义

命名空间:: System.Messaging

程序集:: System.Messaging.dll

重要

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释放 MessageQueue 分配的所有资源。

public:
 void Close();

public void Close ();

member this.Close : unit -> unit

Public Sub Close ()

示例

下面的代码示例关闭消息队列队列。

#using <system.dll>
#using <system.messaging.dll>

using namespace System;
using namespace System::Messaging;
ref class MyNewQueue
{
public:

   // Sends a message to a queue.
   void SendMessage()
   {
      // Connect to a queue on the local computer.
      MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" );

      // Send a message to the queue.
      myQueue->Send( "My message data1." );

      // Explicitly release resources.
      myQueue->Close();

      // Attempt to reaquire resources.
      myQueue->Send( "My message data2." );
      return;
   }

   // Receives a message from a queue.
   void ReceiveMessage()
   {
      // Connect to the a on the local computer.
      MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" );

      // Set the formatter to indicate body contains an Order.
      array<Type^>^p = gcnew array<Type^>(1);
      p[ 0 ] = String::typeid;
      myQueue->Formatter = gcnew XmlMessageFormatter( p );
      try
      {
         // Receive and format the message. 
         Message^ myMessage1 = myQueue->Receive();
         Message^ myMessage2 = myQueue->Receive();
      }
      catch ( MessageQueueException^ ) 
      {
         // Handle sources of any MessageQueueException.
      }
      finally
      {
         // Free resources.
         myQueue->Close();
      }

      return;
   }
};


// Provides an entry point into the application.
// This example closes a queue and frees its 
// resources.
int main()
{
   // Create a new instance of the class.
   MyNewQueue^ myNewQueue = gcnew MyNewQueue;

   // Send a message to a queue.
   myNewQueue->SendMessage();

   // Receive a message from a queue.
   myNewQueue->ReceiveMessage();
   return 0;
}

using System;
using System.Messaging;

namespace MyProject
{

    /// <summary>
    /// Provides a container class for the example.
    /// </summary>
    public class MyNewQueue
    {

        //**************************************************
        // Provides an entry point into the application.
        //	
        // This example closes a queue and frees its
        // resources.
        //**************************************************

        public static void Main()
        {
            // Create a new instance of the class.
            MyNewQueue myNewQueue = new MyNewQueue();

            // Send a message to a queue.
            myNewQueue.SendMessage();

            // Receive a message from a queue.
            myNewQueue.ReceiveMessage();

            return;
        }

        //**************************************************
        // Sends a message to a queue.
        //**************************************************
        
        public void SendMessage()
        {
            // Connect to a queue on the local computer.
            MessageQueue myQueue = new MessageQueue(".\\myQueue");

            // Send a message to the queue.
            myQueue.Send("My message data1.");
            
            // Explicitly release resources.
            myQueue.Close();

            // Attempt to reacquire resources.
            myQueue.Send("My message data2.");

            return;
        }

        //**************************************************
        // Receives a message from a queue.
        //**************************************************
        
        public  void ReceiveMessage()
        {
            // Connect to the a on the local computer.
            MessageQueue myQueue = new MessageQueue(".\\myQueue");

            // Set the formatter to indicate body contains an Order.
            myQueue.Formatter = new XmlMessageFormatter(new Type[]
                {typeof(String)});
            
            try
            {
                // Receive and format the message.
                Message myMessage1 = myQueue.Receive();
                Message myMessage2 = myQueue.Receive();
            }
            
            catch (MessageQueueException)
            {
                // Handle sources of any MessageQueueException.
            }

            // Catch other exceptions as necessary.

            finally
            {
                // Free resources.
                myQueue.Close();
            }

            return;
        }
    }
}

Imports System.Messaging

  
'Provides a container class for the example.

Public Class MyNewQueue



        ' Provides an entry point into the application.
        '	 
        ' This example closes a queue and frees its 
        ' resources.
 

        Public Shared Sub Main()

            ' Create a new instance of the class.
            Dim myNewQueue As New MyNewQueue()

            ' Send a message to a queue.
            myNewQueue.SendMessage()

            ' Receive a message from a queue.
            myNewQueue.ReceiveMessage()

            Return

        End Sub



        ' Sends a message to a queue.
 

        Public Sub SendMessage()

            ' Connect to a queue on the local computer.
            Dim myQueue As New MessageQueue(".\myQueue")

            ' Send a message to the queue.
            myQueue.Send("My message data1.")

            ' Explicitly release resources.
            myQueue.Close()

            ' Attempt to reacquire resources.
            myQueue.Send("My message data2.")

            Return

        End Sub



        ' Receives a message from a queue.


        Public Sub ReceiveMessage()

            ' Connect to the a on the local computer.
            Dim myQueue As New MessageQueue(".\myQueue")

            ' Set the formatter to indicate the body contains an 
            ' Order.
            myQueue.Formatter = New XmlMessageFormatter(New Type() _
                {GetType([String])})

            Try
                ' Receive and format the message. 
                Dim myMessage1 As Message = myQueue.Receive()
                Dim myMessage2 As Message = myQueue.Receive()

            Catch
                ' Handle sources of any MessageQueueException.

                ' Catch other exceptions as necessary.

            Finally

                ' Free resources.
                myQueue.Close()

            End Try

            Return

        End Sub

End Class

注解

Close 释放与 MessageQueue关联的所有资源，包括共享资源（如果适用）。如果这些资源仍然可用（例如调用 Send(Object) 方法时），系统会自动重新获取这些资源，如以下 C# 代码所示。

myMessageQueue.Send("Text 1.");
myMessageQueue.Close();
myMessageQueue.Send("Text 2."); //Resources are re-acquired.

调用 Close时，将清除直接访问消息队列的所有 MessageQueue 属性。 Path、 DefaultPropertiesToSend、 Formatter和 MessageReadPropertyFilter 都保持不变。

Close 不会始终将读取和写入句柄释放到队列，因为它们可能是共享的。可以执行以下任何步骤来确保 Close 将读取和写入句柄释放到队列：

CreateMessageQueue具有独占访问权限的。为此，请调用 MessageQueue(String, Boolean) 或构造函数，并将参数设置为 sharedModeDenyReceivetrue。MessageQueue(String, Boolean, Boolean)
在禁用连接缓存的情况下Create MessageQueue 。为此，请调用构造函数并将 MessageQueue(String, Boolean, Boolean) 参数设置为 enableConnectionCachefalse。
禁用连接缓存。为此，请将属性 EnableConnectionCache 设置为 false。

删除消息队列服务器上的队列之前，应调用 Close 队列。否则，发送到队列的消息可能会引发异常或出现在死信队列中。

下表显示了此方法在各种工作组模式下是否可用。

工作组模式	可用
本地计算机	是
本地计算机和直接格式名称	是
远程计算机	是
远程计算机和直接格式名称	是

适用于

通过

MessageQueue.Close 方法

定义

示例

注解

适用于

其他资源