从另一个Project C＃调用类

Question

I really need your help and to figure this out.

My Project:

AccessProjectMap -- MainClass.cs -- ErrorLog.cs (public) ThreadProjectMap -- StartThread.cs

I'd like to make StartThread my default project when the project starts. Now I need the ErrorLog.cs file in my ThreadProjectMap. I made a reference and I can actually say ErrorLog log = new ErrorLog(); which does also work. When I try to use the ErrorLog in MainClass.cs it's working too.

However I cannot use log inside the main or DoThreading function.

class StartThread {

    static string threadRefresh = ConfigurationManager.AppSettings.Get("refreshTime").ToString();

    Access ac = new Access();
    ErrorLog log = new ErrorLog();

    static void Main(String[] args) {
        log.LogMessageToFile("== Start Main() ==");
        Thread t = new Thread(new ThreadStart(DoThreading));
        t.Start();
        Console.Read();
    }

    static void DoThreading() {
        int refresh = 1;

        while (true) {

            Console.WriteLine("Test");
            log.LogMessageToFile("== Test - inside Thread ==");

            Thread.Sleep(1000);

        }

    }
}

Answer 1

The issue is not because of different projects/namespaces, instead you are trying to access an instance member in a static method .

Make your log field static and it should compile fine.

static ErrorLog log = new ErrorLog(); //Here, make it static

static void Main(String[] args) {
    log.LogMessageToFile("== Start Main() ==");
    Thread t = new Thread(new ThreadStart(DoThreading));
    t.Start();
    Console.Read();
}

Answer 2

The instance you create of ErrorLog on this line:

ErrorLog log = new ErrorLog();

Is an instance variable. The Main and DoThreading methods are static.

You have two options: Either make the ErrorLog static as well, like so:

static ErrorLog log = new ErrorLog();

Or, just instantiate it inside your static methods.