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Sample: Persistent queue listener

 

Applies To: Dynamics 365 (online), Dynamics 365 (on-premises), Dynamics CRM 2016, Dynamics CRM Online

This sample code is for Microsoft Dynamics 365 (online & on-premises).Download the Microsoft Dynamics CRM SDK package.This code can be found in the following location in the download package:

SampleCode\CS\Azure\PersistentQueueListener\PersistentQueueListener.cs

Requirements

This sample code requires the following additional Microsoft Visual Studio project reference: Microsoft.ServiceBus. The Microsoft.ServiceBus.dll assembly can be found in the Microsoft Azure SDK.

Demonstrates

This sample shows how to write a Microsoft Azure Service Bus listener application for a persistent queue endpoint contract.

The listener waits for a Microsoft Dynamics 365 message to be posted to the service bus and to be available in the endpoint queue. When a message is available in the queue, the listener reads the message, prints the Microsoft Dynamics 365 execution context contained in the message to the console, and deletes the message from the queue.

Example


using System;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.Collections.Generic;
using System.Text;

using Microsoft.ServiceBus;
using Microsoft.ServiceBus.Messaging;
using Microsoft.Xrm.Sdk;

namespace Microsoft.Crm.Sdk.Samples
{
    class Program
    {
        public static void Main(string[] args)
        {
            Consumer consumer = new Consumer();

            consumer.CreateQueueClient();
            consumer.ProcessMessages();
            consumer.DeleteQueue();
        }
    }

    internal class Consumer
    {
        private const String MyQueuePath = "MyQueue";
        private QueueDescription queueDescription;
        private QueueClient queueClient;
        private Uri namespaceUri;
        private TransportClientEndpointBehavior credential;

        public Consumer()
        {
            Console.Write("Your Service Namespace: ");
            string serviceNamespace = Console.ReadLine();
            Console.Write("Your Issuer Name: ");
            string issuerName = Console.ReadLine();
            Console.Write("Your Issuer Secret: ");
            string issuerSecret = Console.ReadLine();

            // Configure queue settings.
            this.queueDescription = new QueueDescription(MyQueuePath);
            // Setting Max Size and TTL for demonstration purpose
            // but can be changed per user discretion to suite their system needs.
            // Refer service bus documentation to understand the limitations.
            // Setting Queue max size to 1GB where as default Max Size is 5GB.
            this.queueDescription.MaxSizeInMegabytes = 1024;
            // Setting message TTL to 5 days where as default TTL is 14 days.
            this.queueDescription.DefaultMessageTimeToLive = TimeSpan.FromDays(5);

            // Create management credentials.
            this.credential = new TransportClientEndpointBehavior() 
            {
                TokenProvider = TokenProvider.CreateSharedSecretTokenProvider(issuerName, issuerSecret)
            };

            // Create the URI for the queue.
            this.namespaceUri = ServiceBusEnvironment.CreateServiceUri("sb", serviceNamespace, String.Empty);
            Console.WriteLine("Service Bus Namespace Uri address '{0}'", this.namespaceUri.AbsoluteUri);
        }

        public void CreateQueueClient()
        {
            // get the existing queue or create a new queue if it doesn't exist.
            this.queueClient = GetOrCreateQueue(namespaceUri, this.credential.TokenProvider);
        }

        public void ProcessMessages()
        {
            // Get receive mode (PeekLock or ReceiveAndDelete) from queueClient.
            ReceiveMode mode = this.queueClient.Mode;
            while (true)
            {
                Console.Write("Press [Enter] to retrieve a message from the queue (type quit to exit): ");
                string line = Console.ReadLine();

                if (!string.IsNullOrEmpty(line) && string.Equals(line, "quit", StringComparison.OrdinalIgnoreCase))
                {
                    break;
                }

                // Retrieve a message from the queue.
                Console.WriteLine("Waiting for a message from the queue... ");
                BrokeredMessage message;
                try
                {
                    message = this.queueClient.Receive();
                    // Check if the message received.
                    if (message != null)
                    {
                        try
                        {
                            // Verify EntityLogicalName and RequestName message properties 
                            // to only process specific message sent from Microsoft Dynamics CRM. 
                            string keyRoot = "https://schemas.microsoft.com/xrm/2011/Claims/";
                            string entityLogicalNameKey = "EntityLogicalName";
                            string requestNameKey = "RequestName";
                            object entityLogicalNameValue;
                            object requestNameValue;
                            message.Properties.TryGetValue(keyRoot + entityLogicalNameKey, out entityLogicalNameValue);
                            message.Properties.TryGetValue(keyRoot + requestNameKey, out requestNameValue);

                            // Filter message with specific message properties. i.e. EntityLogicalName=letter and RequestName=Create
                            if (entityLogicalNameValue != null && requestNameValue != null)
                            {
                                if (entityLogicalNameValue.ToString() == "letter" && requestNameValue.ToString() == "Create")
                                {
                                    Console.WriteLine("--------------------------------");
                                    Console.WriteLine(string.Format("Message received: Id = {0}", message.MessageId));
                                    // Display message properties that are set on the brokered message.
                                    Utility.PrintMessageProperties(message.Properties);
                                    // Display body details.
                                    Utility.Print(message.GetBody<RemoteExecutionContext>());
                                    Console.WriteLine("--------------------------------");
                                }
                                else
                                {
                                    continue;
                                }
                            }
                            else
                            {
                                continue;
                            }
                            // If receive mode is PeekLock then set message complete to remove message from queue.
                            if (mode == ReceiveMode.PeekLock)
                            {
                                message.Complete();
                            }
                        }
                        catch (System.Exception ex)
                        {
                            // Indicate a problem, unlock message in queue.
                            if (mode == ReceiveMode.PeekLock)
                            {
                                message.Abandon();
                            }
                            Console.WriteLine(ex.Message);
                            continue;
                        }
                    }
                    else
                    {
                        break;
                    }
                }
                catch (System.TimeoutException e)
                {
                    Console.WriteLine(e.Message);
                    continue;
                }
                catch (System.ServiceModel.FaultException e)
                {
                    Console.WriteLine(e.Message);
                    continue;
                }
            }
        }

        public void DeleteQueue()
        {
            DeleteQueueInternal(namespaceUri, MyQueuePath, credential.TokenProvider);
        }

        private void DeleteQueueInternal(Uri address, string path, TokenProvider tokenProvider)
        {
            var settings = new NamespaceManagerSettings() { TokenProvider = tokenProvider };
            var namespaceClient = new ServiceBus.NamespaceManager(address, settings);
            try
            {
                namespaceClient.DeleteQueue(path);
                Console.WriteLine("Queue deleted successfully.");
            }
            catch (FaultException e)
            {
                Console.WriteLine("Exception when deleting queue.. {0}", e);
            }
        }

        private QueueClient GetOrCreateQueue(Uri namespaceUri, TokenProvider tokenProvider)
        {
            NamespaceManager namespaceClient = new NamespaceManager(namespaceUri, tokenProvider);

            // Create queue if not already exist.
            if (!namespaceClient.QueueExists(MyQueuePath))
            {
                namespaceClient.CreateQueue(this.queueDescription);
                Console.WriteLine("Queue created.");
            }
            else
            {
                Console.WriteLine("Queue already exists.");
            }

            MessagingFactory factory = MessagingFactory.Create(namespaceUri, tokenProvider);
            Console.WriteLine("Creating queue client...");
            return factory.CreateQueueClient(MyQueuePath, ReceiveMode.PeekLock);            
        }
    }

    internal static class Utility
    {
        public static void Print(RemoteExecutionContext context)
        {   
            if (context == null)
            {
                Console.WriteLine("Context is null.");
                return;
            }

            Console.WriteLine("UserId: {0}", context.UserId);
            Console.WriteLine("OrganizationId: {0}", context.OrganizationId);
            Console.WriteLine("OrganizationName: {0}", context.OrganizationName);
            Console.WriteLine("MessageName: {0}", context.MessageName);
            Console.WriteLine("Stage: {0}", context.Stage);
            Console.WriteLine("Mode: {0}", context.Mode);
            Console.WriteLine("PrimaryEntityName: {0}", context.PrimaryEntityName);
            Console.WriteLine("SecondaryEntityName: {0}", context.SecondaryEntityName);

            Console.WriteLine("BusinessUnitId: {0}", context.BusinessUnitId);
            Console.WriteLine("CorrelationId: {0}", context.CorrelationId);
            Console.WriteLine("Depth: {0}", context.Depth);
            Console.WriteLine("InitiatingUserId: {0}", context.InitiatingUserId);
            Console.WriteLine("IsExecutingOffline: {0}", context.IsExecutingOffline);
            Console.WriteLine("IsInTransaction: {0}", context.IsInTransaction);
            Console.WriteLine("IsolationMode: {0}", context.IsolationMode);
            Console.WriteLine("Mode: {0}", context.Mode);
            Console.WriteLine("OperationCreatedOn: {0}", context.OperationCreatedOn.ToString());
            Console.WriteLine("OperationId: {0}", context.OperationId);
            Console.WriteLine("PrimaryEntityId: {0}", context.PrimaryEntityId);
            Console.WriteLine("OwningExtension LogicalName: {0}", context.OwningExtension.LogicalName);
            Console.WriteLine("OwningExtension Name: {0}", context.OwningExtension.Name);
            Console.WriteLine("OwningExtension Id: {0}", context.OwningExtension.Id);
            Console.WriteLine("SharedVariables: {0}", (context.SharedVariables == null ? "NULL" :
                SerializeParameterCollection(context.SharedVariables)));
            Console.WriteLine("InputParameters: {0}", (context.InputParameters == null ? "NULL" :
                SerializeParameterCollection(context.InputParameters)));
            Console.WriteLine("OutputParameters: {0}", (context.OutputParameters == null ? "NULL" :
                SerializeParameterCollection(context.OutputParameters)));
            Console.WriteLine("PreEntityImages: {0}", (context.PreEntityImages == null ? "NULL" :
                SerializeEntityImageCollection(context.PreEntityImages)));
            Console.WriteLine("PostEntityImages: {0}", (context.PostEntityImages == null ? "NULL" :
                SerializeEntityImageCollection(context.PostEntityImages)));
        }

        #region Private methods.
        private static string SerializeEntity(Entity e)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append(Environment.NewLine);
            sb.Append(" LogicalName: " + e.LogicalName);
            sb.Append(Environment.NewLine);
            sb.Append(" EntityId: " + e.Id);
            sb.Append(Environment.NewLine);
            sb.Append(" Attributes: [");
            foreach (KeyValuePair<string, object> parameter in e.Attributes)
            {
                sb.Append(parameter.Key + ": " + parameter.Value + "; ");
            }
            sb.Append("]");
            return sb.ToString();
        }

        private static string SerializeParameterCollection(ParameterCollection parameterCollection)
        {
            StringBuilder sb = new StringBuilder();
            foreach (KeyValuePair<string, object> parameter in parameterCollection)
            {
                if (parameter.Value != null &amp;&amp; parameter.Value.GetType() == typeof(Entity))
                {
                    Entity e = (Entity)parameter.Value;
                    sb.Append(parameter.Key + ": " + SerializeEntity(e));
                }
                else
                {
                    sb.Append(parameter.Key + ": " + parameter.Value + "; ");
                }
            }
            return sb.ToString();
        }
        private static string SerializeEntityImageCollection(EntityImageCollection entityImageCollection)
        {
            StringBuilder sb = new StringBuilder();
            foreach (KeyValuePair<string, Entity> entityImage in entityImageCollection)
            {
                sb.Append(Environment.NewLine);
                sb.Append(entityImage.Key + ": " + SerializeEntity(entityImage.Value));
            }
            return sb.ToString();
        }
        #endregion

        internal static void PrintMessageProperties(IDictionary<string, object> iDictionary)
        {
            if (iDictionary.Count == 0)
            {
                Console.WriteLine("No Message properties found.");
                return;
            }
            foreach (var item in iDictionary)
            {
                String key = (item.Key != null) ? item.Key.ToString() : "";
                String value = (item.Value != null)? item.Value.ToString() : "";
                Console.WriteLine( key + " " + value);
            }
        }
    }
}

See Also

Write a listener application for a Microsoft Azure solution
Sample code for Microsoft Dynamics 365 and Microsoft Azure integration

Microsoft Dynamics 365

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