使用Mono运行控制台应用程序时出现奇怪的错误？

Question

I'm trying to host a WCF service from a console app on my Ubuntu machine using mono, im just using the example code from MDSN to create a sample service, heres my code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.ServiceModel;
using System.ServiceModel.Description;

namespace ConsoleAppTest
{
    class Program
    {
        static void Main(string[] args)
        {
            Uri baseAddress = new Uri("http://localhost:8080/hello");
            using (ServiceHost host = new ServiceHost(typeof(HelloWorldService), baseAddress))
            {
                // Enable metadata publishing.
                ServiceMetadataBehavior smb = new ServiceMetadataBehavior();
                smb.HttpGetEnabled = true;
                smb.MetadataExporter.PolicyVersion = PolicyVersion.Policy15;
                host.Description.Behaviors.Add(smb);

                // Open the ServiceHost to start listening for messages. Since
                // no endpoints are explicitly configured, the runtime will create
                // one endpoint per base address for each service contract implemented
                // by the service.
                host.Open();

                Console.WriteLine("The service is ready at {0}", baseAddress);
                Console.WriteLine("Press <Enter> to stop the service.");
                Console.ReadLine();

                // Close the ServiceHost.
                host.Close();
            }

        }
    }

    [ServiceContract]
    public interface IHelloWorldService
    {
        [OperationContract]
        string SayHello(string name);
    }

    public class HelloWorldService : IHelloWorldService
    {
        public string SayHello(string name)
        {
            return string.Format("Hello, {0}", name);
        }
    }

}

When I build it and upload it to my Ubuntu machine, and run it with mono ConsoleAppTest.exe i get the following error:

Unhandled Exception:
System.InvalidProgramException: Invalid IL code in System.ServiceModel.ServiceHost:.ctor (System.Type,System.Uri[]): method body is empty.

  at ConsoleAppTest.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.InvalidProgramException: Invalid IL code in System.ServiceModel.ServiceHost:.ctor (System.Type,System.Uri[]): method body is empty.

  at ConsoleAppTest.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0

What does it mean that the method body is empty?

Answer 1

We had this issue, then discovered that our reference to System.dll had Copy Local set to True. We were building our application on Windows, then running it under Mono, so our application was being shipped with the System.dll from Windows which it was unable to load under Mono.

The fix was to ensure that the reference to System.dll did not have Copy Local turned on, and that System.dll was not included in the build being run on Mono.