XmlMessageFormatter.TargetTypes Свойство

Определение

Задает набор возможных типов, десериализация которых будет выполняться модулем форматирования из тела предоставляемого сообщения.Specifies the set of possible types that will be deserialized by the formatter from the message provided.

public:
 property cli::array <Type ^> ^ TargetTypes { cli::array <Type ^> ^ get(); void set(cli::array <Type ^> ^ value); };
[System.ComponentModel.Browsable(false)]
[System.Messaging.MessagingDescription("XmlMsgTargetTypes")]
public Type[] TargetTypes { get; set; }
member this.TargetTypes : Type[] with get, set
Public Property TargetTypes As Type()

Значение свойства

Type[]

Массив типа Type, задающий типы объектов, десериализуемых из тела сообщения при чтении данного сообщения.An array of type Type that specifies the types of objects to deserialize from the message body when reading the message.

Атрибуты

Исключения

Значение свойства TargetTypesnull.The TargetTypes property is null.

Примеры

Следующий пример кода отправляет и получает сообщение, которое содержит порядок в очередь и из нее.The following code example sends and receives a message that contains an order to and from a queue.

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

using namespace System;
using namespace System::Messaging;
using namespace System::Drawing;
using namespace System::IO;
ref class Order
{
public:
   int orderId;
   DateTime orderTime;
};

ref class MyNewQueue
{
public:
   static void CreateQueue( String^ queuePath )
   {
      try
      {
         if (  !MessageQueue::Exists( queuePath ) )
         {
            MessageQueue::Create( queuePath );
         }
         else
         {
            Console::WriteLine(  "{0} already exists.", queuePath );
         }
      }
      catch ( MessageQueueException^ e ) 
      {
         Console::WriteLine( e->Message );
      }

   }

   void SendMessage()
   {
      try
      {
         // Create a new order and set values.
         Order^ sentOrder = gcnew Order;
         sentOrder->orderId = 3;
         sentOrder->orderTime = DateTime::Now;

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

         // Create the new order.
         Message^ myMessage = gcnew Message( sentOrder );

         // Send the order to the queue.
         myQueue->Send( myMessage );
      }
      catch ( ArgumentException^ e ) 
      {
         Console::WriteLine( e->Message );
      }

      return;
   }

   void ReceiveMessage()
   {
      // Connect to the a queue 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 ] = Order::typeid;
      myQueue->Formatter = gcnew XmlMessageFormatter( p );
      try
      {
         // Receive and format the message. 
         Message^ myMessage = myQueue->Receive();
         Order^ myOrder = dynamic_cast<Order^>(myMessage->Body);

         // Display message information.
         Console::WriteLine( "Order ID: {0}", myOrder->orderId );
         Console::WriteLine( "Sent: {0}", myOrder->orderTime );
      }
      catch ( MessageQueueException^ ) 
      {
         // Handle Message Queuing exceptions.
      }
      // Handle invalid serialization format.
      catch ( InvalidOperationException^ e ) 
      {
         Console::WriteLine( e->Message );
      }

      // Catch other exceptions as necessary.
      return;
   }
};

int main()
{
   // Create a new instance of the class.
   MyNewQueue^ myNewQueue = gcnew MyNewQueue;

   // Create a queue on the local computer.
   MyNewQueue::CreateQueue( ".\\myQueue" );

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

   // Receive a message from a queue.
   myNewQueue->ReceiveMessage();
   return 0;
}
using System;
using System.Messaging;
using System.Drawing;
using System.IO;

namespace MyProject
{

    // The following example 
    // sends to a queue and receives from a queue.
    public class Order
    {
        public int orderId;
        public DateTime orderTime;
    };	

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

        //**************************************************
        // Provides an entry point into the application.
        //		 
        // This example sends and receives a message from
        // a queue.
        //**************************************************

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

            // Create a queue on the local computer.
            CreateQueue(".\\myQueue");
            
            // Send a message to a queue.
            myNewQueue.SendMessage();

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

            return;
        }

        //**************************************************
        // Creates a new queue.
        //**************************************************

        public static void CreateQueue(string queuePath)
        {
            try	
            {
                if(!MessageQueue.Exists(queuePath))
                {
                    MessageQueue.Create(queuePath);
                }
                else
                {
                    Console.WriteLine(queuePath + " already exists.");
                }
            }
            catch (MessageQueueException e)
            {
                Console.WriteLine(e.Message);
            }
        }

        //**************************************************
        // Sends an Order to a queue.
        //**************************************************
        
        public void SendMessage()
        {
            try
            {

                // Create a new order and set values.
                Order sentOrder = new Order();
                sentOrder.orderId = 3;
                sentOrder.orderTime = DateTime.Now;

                // Connect to a queue on the local computer.
                MessageQueue myQueue = new MessageQueue(".\\myQueue");

                // Create the new order.
                Message myMessage = new Message(sentOrder);

                // Send the order to the queue.
                myQueue.Send(myMessage);
            }
            catch(ArgumentException e)
            {
                Console.WriteLine(e.Message);
            }

            return;
        }

        //**************************************************
        // Receives a message containing an order.
        //**************************************************
        
        public  void ReceiveMessage()
        {
            // Connect to the a queue 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(MyProject.Order)});
            
            try
            {
                // Receive and format the message. 
                Message myMessage =	myQueue.Receive(); 
                Order myOrder = (Order)myMessage.Body;

                // Display message information.
                Console.WriteLine("Order ID: " + 
                    myOrder.orderId.ToString());
                Console.WriteLine("Sent: " + 
                    myOrder.orderTime.ToString());
            }
            
            catch (MessageQueueException)
            {
                // Handle Message Queuing exceptions.
            }

                // Handle invalid serialization format.
            catch (InvalidOperationException e)
            {
                Console.WriteLine(e.Message);
            }
            
            // Catch other exceptions as necessary.

            return;
        }
    }
}
Imports System.Messaging
Imports System.Drawing
Imports System.IO



   
' The following example 
' sends to a queue and receives from a queue.
Public Class Order
      Public orderId As Integer
      Public orderTime As DateTime
End Class

   
  
' Provides a container class for the example.

Public Class MyNewQueue
      
      

   ' Provides an entry point into the application.
   '		 
   ' This example sends and receives a message from
   ' a queue.

   Public Shared Sub Main()
      ' Create a new instance of the class.
      Dim myNewQueue As New MyNewQueue()
        
      ' Create a queue on the local computer.
      CreateQueue(".\myQueue")
         
      ' Send a message to a queue.
      myNewQueue.SendMessage()
       
      ' Receive a message from a queue.
      myNewQueue.ReceiveMessage()
         
      Return
   End Sub
      
      

      ' Creates a new queue.
   Public Shared Sub CreateQueue(queuePath As String)
      Try
         If Not MessageQueue.Exists(queuePath) Then
            MessageQueue.Create(queuePath)
         Else
            Console.WriteLine((queuePath + " already exists."))
         End If
      Catch e As MessageQueueException
         Console.WriteLine(e.Message)
      End Try
   End Sub
       
      

      ' Sends an Order to a queue.

   Public Sub SendMessage()
      Try
            
            ' Create a new order and set values.
            Dim sentOrder As New Order()
            sentOrder.orderId = 3
            sentOrder.orderTime = DateTime.Now
            
            ' Connect to a queue on the local computer.
            Dim myQueue As New MessageQueue(".\myQueue")
            
            
            
            ' Create the new order.
            Dim myMessage As New Message(sentOrder)
            
            ' Send the order to the queue.
            myQueue.Send(myMessage)
      Catch e As ArgumentException
            Console.WriteLine(e.Message)
      End Try 
         
      Return
   End Sub
      
      
      
 
      ' Receives a message containing an order.
 
   Public Sub ReceiveMessage()
         ' Connect to the a queue on the local computer.
         Dim myQueue As New MessageQueue(".\myQueue")
         
         ' Set the formatter to indicate body contains an Order.
         myQueue.Formatter = New XmlMessageFormatter(New Type() {GetType(Order)})
         
         Try
            ' Receive and format the message. 
            Dim myMessage As Message = myQueue.Receive()
            Dim myOrder As Order = CType(myMessage.Body, Order)
            
            ' Display message information.
            Console.WriteLine(("Order ID: " + myOrder.orderId.ToString()))
            Console.WriteLine(("Sent: " + myOrder.orderTime.ToString()))
         
  
         ' Handle invalid serialization format.
         Catch e As InvalidOperationException
            Console.WriteLine(e.Message)
         End Try
         
         ' Catch other exceptions as necessary.
         Return
   End Sub
End Class

Комментарии

Свойства TargetTypeNames и TargetTypes указывают модулю форматирования, какие схемы следует пытаться сопоставить при десериализации сообщения.Both the TargetTypeNames and TargetTypes properties tell the formatter what schemas to attempt to match when deserializing a message. Это позволяет модулю форматирования интерпретировать текст сообщения.This allows the formatter to interpret the message body.

Экземпляр, сериализованный в тексте сообщения, должен соответствовать одной из схем, представленных в массиве типов.The instance serialized in the message body must comply with one of the schemas represented in the type array. При чтении сообщения с помощью метода Receive метод создает объект типа, соответствующий указанной схеме, и считывает в него текст сообщения.When you read the message using the Receive method, the method creates an object of the type that corresponds to the schema identified and reads the message body into it.

При чтении из очереди необходимо задать только одно из двух свойств, но можно задать и то, и другое.Only one of the two properties needs to be set when reading from the queue, but you can set both. Набор типов — это объединенный набор из двух свойств.The set of types is the combined set from the two properties. Решение о том, какое свойство следует использовать, зависит от вашего приложения.The decision of which property to use is specific to your application. Если текст сообщения содержит тип, схема которого не совпадает ни с одним из типов в массиве для любого из свойств, при считывании сообщения будет создано исключение.If the message body contains a type whose schema does not match any of the types in the array for either property, an exception will be thrown when the message is read.

Типы целевых объектов требуются только при чтении из очереди.The target types are only required when reading from the queue. Свойства TargetTypeNames и TargetTypes не нужно задавать для записи в очередь.The TargetTypeNames and TargetTypes properties do not need to be set to write to the queue.

При указании TargetTypes, а не TargetTypeNames, тип существование проверяется во время компиляции, а не на время чтения, уменьшая вероятность ошибки.When specifying TargetTypes rather than TargetTypeNames, type existence is checked at compile time rather than read time, reducing possibility for error.

При использовании TargetTypesможно добавить каждый объект (например, MyClass) в список способом, демонстрируемым TargetTypes = new Type[]{typeof(MyClass), typeof (MyOtherClass)};C# кода.When using TargetTypes, you can add each object (for example, MyClass) to the list in a way demonstrated by the C# code TargetTypes = new Type[]{typeof(MyClass), typeof (MyOtherClass)};.

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