XmlMessageFormatter.TargetTypes 屬性
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
指定可能型別的設定，格式子會從所提供的訊息還原序列化這些型別。
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; }[<System.ComponentModel.Browsable(false)>]
[<System.Messaging.MessagingDescription("XmlMsgTargetTypes")>]
member this.TargetTypes : Type[] with get, setPublic Property TargetTypes As Type()屬性值
Type[]
Type 型別的陣列，讀取訊息時，指定要從訊息主體還原序列化的物件型別。
- 屬性
例外狀況
TargetTypes 屬性為 null。
範例
下列程式代碼範例會傳送和接收包含佇列訂單的訊息。
#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
備註
TargetTypeNames和 TargetTypes 屬性都會告訴格式器在還原串行化訊息時，要嘗試比對的架構。 這可讓格式器解譯訊息本文。
訊息本文中串行化的實例必須符合類型數位中所表示的其中一個架構。 當您使用 Receive 方法讀取訊息時，方法會建立型別的物件，該對象對應至所識別的架構，並將訊息本文讀入其中。
從佇列讀取時，只需要設定兩個屬性的其中一個，但您可以設定這兩個屬性。 型別集合是來自兩個屬性的合併集。 要使用哪一個屬性的決策是您的應用程式專屬的。 如果訊息本文包含的類型，其架構不符合任一屬性之陣列中的任何類型，則會在讀取訊息時擲回例外狀況。
只有在從佇列讀取時，才需要目標類型。 TargetTypeNames和 TargetTypes 屬性不需要設定為寫入佇列。
指定 TargetTypes 而非 TargetTypeNames時，會在編譯時期檢查類型是否存在，而不是讀取時間，以減少錯誤的可能性。
使用 TargetTypes時，您可以使用 C# 程式代碼TargetTypes = new Type[]{typeof(MyClass), typeof (MyOtherClass)};示範的方式，將每個物件新增 (， MyClass) 至清單。
