AcknowledgeTypes Enum
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Specifies the types of acknowledgment message that Message Queuing returns to the sending application.
This enumeration supports a bitwise combination of its member values.
public enum class AcknowledgeTypes[System.Flags]
public enum AcknowledgeTypes[<System.Flags>]
type AcknowledgeTypes = Public Enum AcknowledgeTypes- Inheritance
- Attributes
Fields
| Name | Value | Description |
|---|---|---|
| None | 0 | A mask used to request that no acknowledgment messages (positive or negative) be posted. |
| PositiveArrival | 1 | A mask used to request a positive acknowledgment when the original message reaches the queue. |
| PositiveReceive | 2 | A mask used to request a positive acknowledgment when the original message is successfully retrieved from the queue. |
| NotAcknowledgeReachQueue | 4 | A mask used to request a negative acknowledgment when the original message cannot reach the queue. This can happen when the time-to-reach-queue timer expires or if a message cannot be authenticated. |
| FullReachQueue | 5 | A mask used to request positive acknowledgment if the original message reaches the queue or negative acknowledgment if the time-to-reach-queue timer expires or if the original message cannot be authenticated. |
| NegativeReceive | 8 | A mask used to request a negative acknowledgment when the original message fails to be received from the queue. Using the |
| NotAcknowledgeReceive | 12 | A mask used to request a negative acknowledgment when an error occurs that prevents the original message from being received from the queue before its time-to-be-received timer expires. |
| FullReceive | 14 | A mask used to request positive acknowledgment if the original message is received from the queue before its time-to-be-received timer expires or negative acknowledgment otherwise. |
Examples
The following code example sends and receives a message that contains an order to and from a queue. It specifically requests a positive acknowledgment when the original message reaches or is retrieved from the queue.
#using <system.dll>
#using <system.messaging.dll>
using namespace System;
using namespace System::Messaging;
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()
{
// Connect to a queue on the local computer.
MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" );
// Create a new message.
Message^ myMessage = gcnew Message( "Original Message" );
myMessage->AdministrationQueue = gcnew MessageQueue( ".\\myAdministrationQueue" );
myMessage->AcknowledgeType = (AcknowledgeTypes)(AcknowledgeTypes::PositiveReceive | AcknowledgeTypes::PositiveArrival);
// Send the Order to the queue.
myQueue->Send( myMessage );
return;
}
String^ ReceiveMessage()
{
// Connect to the a queue on the local computer.
MessageQueue^ myQueue = gcnew MessageQueue( ".\\myQueue" );
myQueue->MessageReadPropertyFilter->CorrelationId = true;
array<Type^>^p = gcnew array<Type^>(1);
p[ 0 ] = String::typeid;
myQueue->Formatter = gcnew XmlMessageFormatter( p );
String^ returnString = nullptr;
try
{
// Receive and format the message.
Message^ myMessage = myQueue->Receive();
// Display message information.
Console::WriteLine( "____________________________________________" );
Console::WriteLine( "Original message information--" );
Console::WriteLine( "Body: {0}", myMessage->Body );
Console::WriteLine( "Id: {0}", myMessage->Id );
Console::WriteLine( "____________________________________________" );
returnString = myMessage->Id;
}
catch ( MessageQueueException^ )
{
// Handle Message Queuing exceptions.
}
// Handle invalid serialization format.
catch ( InvalidOperationException^ e )
{
Console::WriteLine( e->Message );
}
// Catch other exceptions as necessary.
return returnString;
}
void ReceiveAcknowledgment( String^ messageId, String^ queuePath )
{
bool found = false;
MessageQueue^ queue = gcnew MessageQueue( queuePath );
queue->MessageReadPropertyFilter->CorrelationId = true;
queue->MessageReadPropertyFilter->Acknowledgment = true;
try
{
while ( queue->PeekByCorrelationId( messageId ) != nullptr )
{
Message^ myAcknowledgmentMessage = queue->ReceiveByCorrelationId( messageId );
// Output acknowledgment message information. The correlation Id is identical
// to the id of the original message.
Console::WriteLine( "Acknowledgment Message Information--" );
Console::WriteLine( "Correlation Id: {0}", myAcknowledgmentMessage->CorrelationId );
Console::WriteLine( "Id: {0}", myAcknowledgmentMessage->Id );
Console::WriteLine( "Acknowledgment Type: {0}", myAcknowledgmentMessage->Acknowledgment );
Console::WriteLine( "____________________________________________" );
found = true;
}
}
catch ( InvalidOperationException^ e )
{
// This exception would be thrown if there is no (further) acknowledgment message
// with the specified correlation Id. Only output a message if there are no messages;
// not if the loop has found at least one.
if ( !found )
{
Console::WriteLine( e->Message );
}
// Handle other causes of invalid operation exception.
}
}
};
int main()
{
// Create a new instance of the class.
MyNewQueue^ myNewQueue = gcnew MyNewQueue;
// Create new queues.
MyNewQueue::CreateQueue( ".\\myQueue" );
MyNewQueue::CreateQueue( ".\\myAdministrationQueue" );
// Send messages to a queue.
myNewQueue->SendMessage();
// Receive messages from a queue.
String^ messageId = myNewQueue->ReceiveMessage();
// Receive acknowledgment message.
if ( messageId != nullptr )
{
myNewQueue->ReceiveAcknowledgment( messageId, ".\\myAdministrationQueue" );
}
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 sends and receives a message from
// a queue.
//**************************************************
public static void Main()
{
// Create a new instance of the class.
MyNewQueue myNewQueue = new MyNewQueue();
// Create new queues.
CreateQueue(".\\myQueue");
CreateQueue(".\\myAdministrationQueue");
// Send messages to a queue.
myNewQueue.SendMessage();
// Receive messages from a queue.
string messageId = myNewQueue.ReceiveMessage();
// Receive acknowledgment message.
if(messageId != null)
{
myNewQueue.ReceiveAcknowledgment(messageId, ".\\myAdministrationQueue");
}
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 a string message to a queue.
//**************************************************
public void SendMessage()
{
// Connect to a queue on the local computer.
MessageQueue myQueue = new MessageQueue(".\\myQueue");
// Create a new message.
Message myMessage = new Message("Original Message");
myMessage.AdministrationQueue = new MessageQueue(".\\myAdministrationQueue");
myMessage.AcknowledgeType = AcknowledgeTypes.PositiveReceive | AcknowledgeTypes.PositiveArrival;
// Send the Order to the queue.
myQueue.Send(myMessage);
return;
}
//**************************************************
// Receives a message containing an Order.
//**************************************************
public string ReceiveMessage()
{
// Connect to the a queue on the local computer.
MessageQueue myQueue = new MessageQueue(".\\myQueue");
myQueue.MessageReadPropertyFilter.CorrelationId = true;
// Set the formatter to indicate body contains an Order.
myQueue.Formatter = new XmlMessageFormatter(new Type[]
{typeof(string)});
string returnString = null;
try
{
// Receive and format the message.
Message myMessage = myQueue.Receive();
// Display message information.
Console.WriteLine("____________________________________________");
Console.WriteLine("Original message information--");
Console.WriteLine("Body: " +myMessage.Body.ToString());
Console.WriteLine("Id: " + myMessage.Id.ToString());
Console.WriteLine("____________________________________________");
returnString = myMessage.Id;
}
catch (MessageQueueException)
{
// Handle Message Queuing exceptions.
}
// Handle invalid serialization format.
catch (InvalidOperationException e)
{
Console.WriteLine(e.Message);
}
// Catch other exceptions as necessary.
return returnString;
}
//**************************************************
// Receives a message containing an Order.
//**************************************************
public void ReceiveAcknowledgment(string messageId, string queuePath)
{
bool found = false;
MessageQueue queue = new MessageQueue(queuePath);
queue.MessageReadPropertyFilter.CorrelationId = true;
queue.MessageReadPropertyFilter.Acknowledgment = true;
try
{
while(queue.PeekByCorrelationId(messageId) != null)
{
Message myAcknowledgmentMessage = queue.ReceiveByCorrelationId(messageId);
// Output acknowledgment message information. The correlation Id is identical
// to the id of the original message.
Console.WriteLine("Acknowledgment Message Information--");
Console.WriteLine("Correlation Id: " + myAcknowledgmentMessage.CorrelationId.ToString());
Console.WriteLine("Id: " + myAcknowledgmentMessage.Id.ToString());
Console.WriteLine("Acknowledgment Type: " + myAcknowledgmentMessage.Acknowledgment.ToString());
Console.WriteLine("____________________________________________");
found = true;
}
}
catch (InvalidOperationException e)
{
// This exception would be thrown if there is no (further) acknowledgment message
// with the specified correlation Id. Only output a message if there are no messages;
// not if the loop has found at least one.
if (!found)
{
Console.WriteLine(e.Message);
}
// Handle other causes of invalid operation exception.
}
}
}
}
Imports System.Messaging
' 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 new queues.
CreateQueue(".\myQueue")
CreateQueue(".\myAdministrationQueue")
' Send messages to a queue.
myNewQueue.SendMessage()
' Receive messages from a queue.
Dim messageId As String = myNewQueue.ReceiveMessage()
' Receive acknowledgment message.
If Not (messageId Is Nothing) Then
myNewQueue.ReceiveAcknowledgment(messageId, ".\myAdministrationQueue")
End If
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 a string message to a queue.
Public Sub SendMessage()
' Connect to a queue on the local computer.
Dim myQueue As New MessageQueue(".\myQueue")
' Create a new message.
Dim myMessage As New Message("Original Message")
myMessage.AdministrationQueue = New MessageQueue(".\myAdministrationQueue")
myMessage.AcknowledgeType = AcknowledgeTypes.PositiveReceive Or AcknowledgeTypes.PositiveArrival
' Send the Order to the queue.
myQueue.Send(myMessage)
Return
End Sub
' Receives a message containing an Order.
Public Function ReceiveMessage() As String
' Connect to the a queue on the local computer.
Dim myQueue As New MessageQueue(".\myQueue")
myQueue.MessageReadPropertyFilter.CorrelationId = True
' Set the formatter to indicate body contains an Order.
myQueue.Formatter = New XmlMessageFormatter(New Type() {GetType(String)})
Dim returnString As String = Nothing
Try
' Receive and format the message.
Dim myMessage As Message = myQueue.Receive()
' Display message information.
Console.WriteLine("____________________________________________")
Console.WriteLine("Original message information--")
Console.WriteLine(("Body: " + myMessage.Body.ToString()))
Console.WriteLine(("Id: " + myMessage.Id.ToString()))
Console.WriteLine("____________________________________________")
returnString = myMessage.Id
' Handle invalid serialization format.
Catch e As InvalidOperationException
Console.WriteLine(e.Message)
End Try
' Catch other exceptions as necessary.
Return returnString
End Function 'ReceiveMessage
' Receives a message containing an Order.
Public Sub ReceiveAcknowledgment(messageId As String, queuePath As String)
Dim found As Boolean = False
Dim queue As New MessageQueue(queuePath)
queue.MessageReadPropertyFilter.CorrelationId = True
queue.MessageReadPropertyFilter.Acknowledgment = True
Try
While Not (queue.PeekByCorrelationId(messageId) Is Nothing)
Dim myAcknowledgmentMessage As Message = queue.ReceiveByCorrelationId(messageId)
' Output acknowledgment message information. The correlation Id is identical
' to the id of the original message.
Console.WriteLine("Acknowledgment Message Information--")
Console.WriteLine(("Correlation Id: " + myAcknowledgmentMessage.CorrelationId.ToString()))
Console.WriteLine(("Id: " + myAcknowledgmentMessage.Id.ToString()))
Console.WriteLine(("Acknowledgment Type: " + myAcknowledgmentMessage.Acknowledgment.ToString()))
Console.WriteLine("____________________________________________")
found = True
End While
Catch e As InvalidOperationException
' This exception would be thrown if there is no (further) acknowledgment message
' with the specified correlation Id. Only output a message if there are no messages;
' not if the loop has found at least one.
If found = False Then
Console.WriteLine(e.Message)
End If
End Try
End Sub
End Class
Remarks
The AcknowledgeTypes class provides a set of flags that you can combine to request one or more categories of acknowledgment messages.
When an application sends a message, it can request that Message Queuing return acknowledgment messages indicating the success or failure of the original message. Message Queuing sends these acknowledgment messages to the administration queue you specify. Acknowledgment types can be divided broadly into four groups: positive arrival acknowledgments, positive read acknowledgments, negative arrival acknowledgments, and negative read acknowledgments. Requesting acknowledgments enables your application to receive notification of certain occurrences - for example, a message reaching its destination queue, a message being retrieved, or a time-out preventing a message from reaching or being retrieved from the destination queue.
When you are using the Message class to send messages to a queue, you specify the types of acknowledgments your application should receive in the AcknowledgeType property, as well as the administration queue that receives the acknowledgment messages in the AdministrationQueue property.
When you use the Message class to read acknowledgment messages in the administration queue, the instance's Acknowledgment property indicates the condition responsible for the acknowledgment message, for example, if a time-out expired before the original message was read from the queue.
