Question

I’m having problems with passing loaded data from one thread to another to add the data to the form. I added another object into “var obj = new object[] { names }” and got “Parameter count mismatch”. I’d still prefer to pass “Clients” and “Messages” from “LoadData()” in the second thread to “UpdateFormMethod()” in the first one, but I have no idea how to do it. I’d be grateful if anyone could help me with this problem.

Here’s the important part of the code within one class:

private readonly Thread _thread;
    public readonly Loader Loader = new Loader();
    public Dictionary<string, Client> Clients;
    public Dictionary<string, Message> Messages;
    private bool _stopData = false;
    public delegate void UpdateForm(object data);
    public UpdateForm MyDelegate;

    public Fcon() {
        InitializeComponent();
        MyDelegate = new UpdateForm(UpdateFormMethod);
        _thread = new Thread(LoadData);
        _thread.Start();
    }

    public void UpdateFormMethod(object data) {
        foreach (var str in ((IEnumerable<string>)data).Where(str => !fcon_container_users_list.Items.Contains(str))) {
            fcon_container_users_list.Items.Insert(0, str);
        }
    }

    public void LoadData() {
        while (!_stopData) {
            Clients = Loader.GetClients(Operator);
            Messages = Loader.GetMessages(Operator);
            var status = Loader.SetStatus(Operator);
            var names = new string[Clients.Count];
            var x = 0;
            foreach (var kvp in Clients) {
                names[x] = "user_" + kvp.Value.id_fcon_client;
                x++;
            }
            var obj = new object[] { names };
            this.Invoke(this.MyDelegate, obj);    
            Thread.Sleep(1000);
        }
    }

    public void StopData() {
        _stopData = true;
    }

Answer 1

It sounds like you’re not entirely clear where the signature is coming from. It’s your own delegate – if you want to change the signature, just change the signature of the delegate and the method implementing it:

public delegate void UpdateForm(IEnumerable<string> data, int foo);

...

public void UpdateFormMethod(IEnumerable<string> data, int foo) {
    foreach (var str in data.Where(str => 
               !fcon_container_users_list.Items.Contains(str))) {
        fcon_container_users_list.Items.Insert(0, str);
    }
}

Then:

var obj = new object[] { names, someIntVariable };
this.Invoke(this.MyDelegate, obj);

Or more simply:

this.Invoke(this.MyDelegate, names, someIntVariable);

I’d probably use the existing Action<T>, Action<T1, T2> delegates rather than creating new ones though OR T Func<T1 [,T2]> if you require a return type.