c# using other class method

Question

Thanks to NHMountainGoat for an answer! Implementing Interface looks a good choice so we have only the 'needed' method instanciated. It looks like this now: EDIT

class Machine
{
    //REM: MachineConnexion is a link to the main server where asking the data
    internal linkToPLC LinkToPLC;
    public IlinkToPLC ILinkPLC;
    public interface IlinkToPLC//Interface to linkPLC
    {
        Int16 MachineNumIS { get; set; }
    }
    internal class linkToPLC : IlinkToPLC
    {
        private Int16 Act_MachineNum;
        private List<string> genlnkPLCCanvas;
        private List<string> genlnkPLCworkingwith;
        static private List<string> ListSymbolNoExist;
        private string[] ListToPLClnk = {
                          "GlobalFolder.PMachine[{0}].",
                          "GlobalFolder.PMachine[{0}].STATE.",
                          "GlobalFolder.Machine[{0}].",
                          "GlobalFolder.Machine[{0}].STATE.",
                        };
        public linkToPLC()//ctor
        {
            genlnkPLCCanvas = new List<string>(ListToPLClnk);
            genlnkPLCworkingwith = new List<string>(ListToPLClnk);
            ListSymbolNoExist = new List<string>();
            Act_MachineNum = MachineNumIS;
        }
        public Int16 MachineNumIS { get { return (Int16)ReadWriteMachine("data"); } set { ReadWriteMachine("data", value); } }
        public string ValueExist(string ValueToreach, bool WorkingDATA = false)
        {
            if (!WorkingDATA)
            {
                for (int inc = 0; inc < genlnkPLCworkingwith.Count; inc++)
                {
                    string StrValueToReach = genlnkPLCworkingwith[inc] + ValueToreach;
                    if (MachineConnexion.SymbolExists(StrValueToReach))
                    {
                        ListSymbolNoExist.Clear();
                        return StrValueToReach;
                    }
                    else ListSymbolNoExist.Add(genlnkPLCworkingwith[inc] + ValueToreach);
                }
            }
            else if (WorkingDATA)
            {
                string StrValueToReach = genlnkPLCworkingwith[10] + ValueToreach;
                if (MachineConnexion.SymbolExists(StrValueToReach))
                {
                    ListSymbolNoExist.Clear();
                    return StrValueToReach;
                }
                else ListSymbolNoExist.Add(genlnkPLCworkingwith[10] + ValueToreach);
            }
            if (ListSymbolNoExist.Count != 0)
            {
                string ErrorList = "";
                for (int inc = 0; inc < ListSymbolNoExist.Count; inc++)
                {
                    ErrorList = string.Concat(ErrorList + "Num: " + inc.ToString() + " " + ListSymbolNoExist[inc].ToString() + "\n");
                }
                Console.WriteLine("Error" + ErrorList);
            }
            return null;
        }
        public object ReadWriteMachine(string VariableName, object DataToWrite = null, bool WorkingDATA = false)
        {
            string valueToFind = "";
            if (ValueExist(VariableName) != "FALSE")
            {
                if (DataToWrite != null) { MachineConnexion.WriteSymbol(valueToFind, DataToWrite); }
                return MachineConnexion.ReadSymbol(valueToFind);
            }
            return VariableName;
        }
    }
    public Machine()                  //constructor
    {
        LinkToPLC = new linkToPLC();
    }
}

And It doesn't work telling me that the reference object is not defined to an instance of the object..... in the line : Machine() LinkToPLC = new linkToPLC();//REM I found the bug, it was me ;o)) 24112016

//REM 24112016

What are the main differences between those two concept: static Instance and Interface?

Example:

  class Program
{
    static void Main(string[] args)
    {
        ITestInterface InterInstance = new TestInterface();
        //test Interface
        bool value1 = true;
        value1 = InterInstance.invert(value1);
        InterInstance.print(value1);
        //test Instance static
        TestStaticInstance staticInstance = new TestStaticInstance();
        staticInstance.Instance.invert(value1);
        staticInstance.Instance.print(value1);
        Console.ReadKey();
    }
}
class TestInterface : ITestInterface
{
    public bool invert(bool value)
    {
        return !value;
    }
    public void print(bool value)
    { 
    Console.WriteLine(value.ToString()+"\n");
    }
    private void methodX()
    { }
}
interface ITestInterface
{
    bool invert(bool value);
    void print(bool value);
}
public class TestStaticInstance
{
    public TestStaticInstance Instance;
    public TestStaticInstance()
    {
        Instance = this;
    }
    internal bool invert(bool value)
    {
        return !value;
    }
    internal void print(bool value)
    {
        Console.WriteLine(value.ToString());
    }
}

Thanks

Answer 1

Can you structure your other classes to take an instance of the link class? See:

/// <summary>
/// just a stub to demonstrate the model
/// </summary>
internal class Machine
{
    public string ReadData() { return "this is data"; }
    public void WriteData(string data) { Console.WriteLine(data); }
}

internal interface IMachineDataAccessor
{
    string Read();
    void Write(string data);
}

class LinkClass : IMachineDataAccessor
{
    protected Machine _machine;

    public LinkClass(Machine machine)
    {
        _machine = machine;
    }

    public void DoMyWork()
    {
        // insert work somewhere in here.

        string dataFromMachine = Read();

        Write("outbound data");
    }

    public string Read()
    {
        return _machine.ReadData();
    }

    public void Write(string data)
    {
        _machine.WriteData(data);
    }
}

class PersistentClass
{
    IMachineDataAccessor _machineImpl;

    public PersistentClass(IMachineDataAccessor machineAccessImplementation) 
    {
        _machineImpl = machineAccessImplementation;
    }

    public void DoMyWork()
    {
        string dataFromMachine = _machineImpl.Read();

        // insert work here.  Or anywhere, actually..

        _machineImpl.Write("outbound data");
    }
}

class StateClass
{
    IMachineDataAccessor _machineImpl;

    public StateClass(IMachineDataAccessor machineAccessImplementation) 
    {
        _machineImpl = machineAccessImplementation;
    }

    public void DoMyWork()
    {
        string dataFromMachine = _machineImpl.Read();

        // insert work here.  Or anywhere, actually..

        _machineImpl.Write("outbound data");
    }
}

static void Main(string[] args)
{
    LinkClass link = new LinkClass(new Machine());
    PersistentClass persistent = new PersistentClass(link as IMachineDataAccessor);
    StateClass state = new StateClass(link as IMachineDataAccessor);

    persistent.DoMyWork();
    state.DoMyWork();
    link.DoMyWork();
}