简单的COM +服务器引发意外异常

Question

I wrote a simple ServicedComponent

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.EnterpriseServices;

namespace ComPlusServer
{
    [ComVisible(true)]
    [ClassInterface(ClassInterfaceType.AutoDual)]
    [Guid("9C674ECA-1B71-42EA-9DB2-9A0EA57EC121")]
    [Description("Hello Server")]
    public class HelloServer : ServicedComponent
    {
        [Description("Say Hello!")]
        public String SayHello()
        {
            return "Hello!, "; 
        }
    }
}

and a Windows Forms application

using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using ComPlusServer;

namespace Client
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            HelloServer server = new HelloServer();

            MessageBox.Show(server.SayHello(), "Message from HelloServer");
        }
    }
}

on the Component Services MMC, on the application properties, security tab I lowered Authentication Level for Calls to None and Impersonation Level to Identify and Unchecked Enforce access checks for this application on Authorization.

I keep getting a ServicedComponentException exception saying

Method-level role based security requires an interface definition for class method.

Any idea on this?

Answer 1

I believe that it means that methods of your Component class needs to be defined in an interface.

[ComVisable(true)]
public interface IHelloServer
{
    public String SayHello(); 
}

Now have your componet class implement the interface:

[ComVisable(true)]
[ClassInterface(ClassInterfaceType.AutoDual)]
[ComDefaultInterface(typeof(IHelloServer))]     
[Guid("9C674ECA-1B71-42EA-9DB2-9A0EA57EC121")]     
[Description("Hello Server")]     
public class HelloServer : ServicedComponent, IHelloServer     
{         
    [Description("Say Hello!")]         
    public String SayHello()         
    {             
        return "Hello!, ";          
    }     
}