在WCF服务与其托管Windows服务之间传递数据

Question

I have a project that wants me to communicate with a server. I need to send data processed from a standalone application on client side to the server. For this I am using a wcf service that interacts with the server. This service is hosted in a windows service. Now my problem begins. I need to monitor a folder, write/read some files and delete them. For this I am using the same windows service as the one hosting the wcf service. How can I pass data between the two services? For example I would like to read a file using the windows service and pass the data to wcf service which then passes it to the server and back.

Answer 1

If you just want to be able to communicate between two services hosted in a windows service, one solution I have used is to store a static session state in the windows service itself. In Program.cs, I declare a static field which stores the session state, and I modify the constructors of my two services to take a reference to this object:

static class Program
{
    private static SessionState sessionState = new SessionState() { SessionID = "100" };

    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    static void Main()
    {
        ServiceBase[] servicesToRun;
        servicesToRun = new ServiceBase[] 
            {
                new Service1(sessionState),
                new Service2(sessionState)
            };

        ServiceBase.Run(servicesToRun);
    }
}

I have a class called SessionState which I use to store any data which I want to transfer between my hosted services. In this instance I am just giving the session an ID property:

public class SessionState
{
    public string SessionID { get; set; }
}

Service1 and Service2 store a reference to the static session state, and in my example I just modify the sessionID in one of the two threads:

public partial class Service1 : ServiceBase
{
    private SessionState sessionState;

    public Service1(SessionState sessionState)
    {
        this.sessionState = sessionState;
        InitializeComponent();
    }

    protected override void OnStart(string[] args)
    {
        Console.WriteLine("Service 1 started.");
        Task tsk = new Task(() => this.DoStuff());
        tsk.Start();
    }

    protected override void OnStop()
    {
    }

    private void DoStuff()
    {
        Console.WriteLine("Session state for service 1 is " + this.sessionState.SessionID);

        Thread.Sleep(2000);

        Console.WriteLine("Session state for service 1 is " + this.sessionState.SessionID);
    }
}

public partial class Service2 : ServiceBase
{
    private SessionState sessionState;

    public Service2(SessionState sessionState)
    {
        this.sessionState = sessionState;

        InitializeComponent();
    }

    protected override void OnStart(string[] args)
    {
        Console.WriteLine("Service 2 started.");
        Task tsk = new Task(() => this.DoStuff());
        tsk.Start();
    }

    protected override void OnStop()
    {
    }

    private void DoStuff()
    {
        Console.WriteLine("Session state for service 2 is " + this.sessionState.SessionID);

        Thread.Sleep(1000);
        this.sessionState.SessionID = "200";

        Console.WriteLine("Session state for service 2 is " + this.sessionState.SessionID);
    }
}

Now when I run the Windows Service (with a Console window attached) I get the following:

Hope this helps!

Alex