Debugging a Windows Service

Question

I am making a Windows Service and I want to debug it.

This is the error I get when I try to debug it:

Cannot start service from the command line or a debugger. A Windows service must be first installed and then started with the Server Explorer, Windows Services Administrative TOll or the NET start command.

I have already installed my service using InstallUtil, but I am still facing problems.

Also, when I try to attach a process, my service goes into the running mode, it never starts debugging.

EDIT: DO we have to reinstall the Windows Service everytime we make a change or just building it would suffice?

Answer 1

In your OnStart use something like this:

#if DEBUG
if(!System.Diagnostics.Debugger.IsAttached)
   System.Diagnostics.Debugger.Launch();
#endif

Answer 2

For the most use cases it's good enough to run the service as console application. To do this, I usually have the following startup code:

private static void Main(string[] args) {
    if (Environment.UserInteractive) {
        Console.WriteLine("My Service");
        Console.WriteLine();
        switch (args.FirstOrDefault()) {
        case "/install":
            ManagedInstallerClass.InstallHelper(new[] {Assembly.GetExecutingAssembly().Location});
            break;
        case "/uninstall":
            ManagedInstallerClass.InstallHelper(new[] {"/u", Assembly.GetExecutingAssembly().Location});
            break;
        case "/interactive":
            using (MyService service = new MyService(new ConsoleLogger())) {
                service.Start(args.Skip(1));
                Console.ReadLine();
                service.Stop();
            }
            break;
        default:
            Console.WriteLine("Supported arguments:");
            Console.WriteLine(" /install      Install the service");
            Console.WriteLine(" /uninstall    Uninstall the service");
            Console.WriteLine(" /interactive  Run the service interactively (on the console)");
            break;
        }
    } else {
        ServiceBase.Run(new MyService());
    }
}

This makes it easy not only to run and debug the service, but it can then also install and uninstall without needing the InstallUtil program.