msmq-dlq.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Messaging;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace MsmqDeadLetterQueuePoC
{
    class Program
    {
        const string PREFIX = "FormatName:" + DIRECTPREFIX;
        const string DIRECTPREFIX = "DIRECT=OS:";
        const string PRIVATE = "\\private$\\";

        static void Main(string[] args)
        {
            var deadLetter = @"SIMON-MAC\PRIVATE$\DeadLetter"; //GetPath("SIMON-MAC", "DeadLetter");
            var notExistingQUeue = GetPath("SIMON-MAC", "timeouts");//GetPath("NoMachine", "NoQueue");


            using (var queue = new MessageQueue(notExistingQUeue))
            {
                var messageType = typeof(Message);
                var propType = messageType.Assembly.GetType("System.Messaging.Interop.MessagePropertyVariants");
                var flagsInstance = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic;
                var propField = messageType.GetField("properties", flagsInstance);
                var setString = propType.GetMethod("SetString", flagsInstance);
                var setUI4 = propType.GetMethod("SetUI4", flagsInstance);
                var setUI1 = propType.GetMethod("SetUI1", flagsInstance);
                var setUI4Vector = propType.GetMethod("SetUI1Vector", flagsInstance);

                
                var message = new Message();
                var ctor = propType.GetConstructor(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance, null, new[] {typeof(int), typeof(int)}, null);
                var newProps = ctor.Invoke(new object[] {70, 1});
                setUI4Vector.Invoke(newProps, new object[] {2, new byte[20]});
                propField.SetValue(message, newProps);

                //message.TimeToReachQueue = TimeSpan.FromDays(1000); //TimeSpan.FromSeconds(30);
                message.TimeToBeReceived = TimeSpan.FromDays(1000);
                setUI1.Invoke(newProps, new object[] { 7, (byte)1 }); //Enable dead letter
                var buffer = StringToBytes(deadLetter);
                setString.Invoke(newProps, new object[] { 67, buffer });
                setUI4.Invoke(newProps, new object[] { 68, deadLetter.Length });
                queue.Send(message, MessageQueueTransactionType.Single);
            }

            Console.WriteLine("Press <enter> to exit");
            Console.ReadLine();
        }

        static string GetPath(string machine, string queue)
        {
            return PREFIX + machine + PRIVATE + queue;
        }

        internal static byte[] StringToBytes(string value)
        {
            //var buffer = new byte[]
            //value.CopyTo(0, this.buffer, 0, value.Length);
            //this.buffer[value.Length] = '\0';

            int length = value.Length * 2 + 1;
            byte[] bytes = new byte[length];
            bytes[length - 1] = (byte)0;
            Encoding.Unicode.GetBytes(value.ToCharArray(), 0, value.Length, bytes, 0);
            return bytes;
        }
    }
}