Help explain code with delegates

Im new to C# and the framework Im playing with and Im trying to figure out how some code works (there is nothing wrong with the code). Its a client/server application that sends some text from the client to the server and then receives and displays the same string in a textbox. The code below is from the client and its form. Only the stuff for receiving the string from the server is included here. I included some comments from the framework.

public class TestModuleMobile : PreCom.Core.ModuleBase, PreCom.Core.IForm
{
    public delegate void ReceiveDelegate(string data);
    public event ReceiveDelegate DataReceived;

    public void Receive(byte[] data)
    {
        string text = Encoding.UTF8.GetString(data, 0, data.Length);

        if (DataReceived != null)
            DataReceived.Invoke(text);
    }

    public override bool Initialize()
    {
        PreCom.Application.Instance.Communication.Register(99, Receive);         
    // Register(uint receiverID, RecieveDelegate receiver): Called by modules to register for communication.
    //
    //      Parameters: 
    //          receiverID:
    //              Module Id
    //          receiver:
    //              The module receive function that will be called by the framework when data
    //              arrives to specific module. (This method should return as soon as possible
    //              to avoid timeouts)
        _isInitialized = true;
        return true;
    }
}

public partial class TestModuleMobileForm : PreCom.Controls.PreComForm
{
    TestModuleMobile _module;

    开发者_JS百科public TestModuleMobileForm(TestModuleMobile module)
    {
        _module = module;
        _module.DataReceived += new TestModuleMobile.ReceiveDelegate(DataReceived);
        InitializeComponent();
    }

    void DataReceived(string data)
    {
        if (InvokeRequired)
        {
            ThreadStart myMethod = delegate { DataReceived(data); };
            this.BeginInvoke(myMethod);
            return;
        }  
        listBox1.Items.Insert(0, data);
        this.preComInput21.Text = "";
    }
}

Questions:

1. public override bool Initialize()

The function call to Register takes a ReceiveDelegate object as a second parameter. So how can I send a function to it (Receive) when its just a function? How does this work?

2. public void Receive(byte[] data)

What happens in the if-case? How does invoke work?

3. void DataReceived(string data)

What happens in the if-case (line by line)?

There are many related posts here on Stackoverflow which you can browse through to get a better understanding of delegates. Once you have read through them, take a relook at your code and you will find it easier to understand.

Tip: Check to the right side of this web page to see all the related posts.

You need a full understading of delegates so you better start by reading these in order:

1. Delegates (C# Programming Guide)
2. Delegates Tutorial
3. Delegates and Events in C# / .NET