C#

using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
 
[Serializable()]
public class MyClass {
 
	public MyClass(string name) {
 		_Name = name;
	}
 
	public string Name {
		get { return _Name; }
	}
 
	private string _Name;
 
}
 
[Serializable()]
class MyClassCollection {
 
	public MyClassCollection() {
		_Items = new MyClass[4];
	}
 
	public MyClass this[int index] {
		get { return _Items[index]; }
		set { _Items[index] = value; }
	}
 
	public override string ToString() {
		string result = "MyClassCollection {";
		for (int i = 0; i < _Items.Length; i++)
			result += (i != 0 ? ", " : "") + (_Items[i] != null ? _Items[i].Name : "[null]");
		result += "}";
		return result;
	}
 
	private MyClass[] _Items;
 
	[STAThread]
	static void Main(string[] args) {
		BinaryFormatter formatter = new BinaryFormatter();
		MemoryStream stream = new MemoryStream();
		// Populate collection
		MyClassCollection col = new MyClassCollection();
		col[0] = new MyClass("Item #1");
		col[2] = new MyClass("Item #2");
		Console.WriteLine(col);
		// Serialize collection and reset stream to beginning
		formatter.Serialize(stream, col);
		col = null;
		stream.Seek(0, SeekOrigin.Begin);
		// Deserialize collection
		col = (MyClassCollection)formatter.Deserialize(stream);
		stream.Close();
		Console.WriteLine(col);
		Console.Read();
	}
 
}

MyClassCollection {Item #1, [null], Item #2, [null]}
MyClassCollection {Item #1, [null], Item #2, [null]}

public class Form1 : System.Windows.Forms.Form
{
  private System.Windows.Forms.Button button1;
  private System.Windows.Forms.Button button2;

  private System.ComponentModel.Container components = null;

	public Form1()
	{
		InitializeComponent();
	}

	protected override void Dispose( bool disposing )
	{
		if( disposing )
		{
			if (components != null) 
			{
				components.Dispose();
			}
		}
		base.Dispose( disposing );
	}

	private void InitializeComponent()
	{
    this.button1 = new System.Windows.Forms.Button();
    this.button2 = new System.Windows.Forms.Button();
    this.SuspendLayout();

    this.button1.Location = new System.Drawing.Point(64, 112);
    this.button1.Name = "button1";
    this.button1.TabIndex = 0;
    this.button1.Text = "button1";
    this.button1.Click += new System.EventHandler(this.button1_Click);

    this.button2.Location = new System.Drawing.Point(160, 112);
    this.button2.Name = "button2";
    this.button2.TabIndex = 1;
    this.button2.Text = "button2";
    this.button2.Visible = false;
    this.button2.Click += new System.EventHandler(this.button2_Click);

    this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
    this.ClientSize = new System.Drawing.Size(292, 273);
    this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                this.button2,
                                                                this.button1});
    this.Name = "Form1";
    this.Text = "Form1";
    this.ResumeLayout(false);

  }
	
	private void button1_Click(object sender, System.EventArgs e)
  {
    button2.Visible = true;
    button1.Visible = false;
  }

  private void button2_Click(object sender, System.EventArgs e)
  {
    button2.Visible = false;
    button1.Visible = true;
  }
}

ucInit1.button.Clicked += new EventHandler(ShowUCCreate);

....

void ShowUCCreate(object sender, EventArgs e)
{
  UCCreate newPanel = new UCCreate();
  newPanel.Location = new Point(376, 8);
  newPanel.Size = new Size (280, 140);
  this.Parent.Controls.Add(newPanel);
}

delegate void FooHandler(string name);

class ABC
{
  public FooHandler Foo;

  public void InvokeFoo()
  {
    Foo("Hello from ABC");
  }
}

class XYZ
{
  static void MyFoo(string name)
  {
    Console.WriteLine(name);
  }

  static void Main()
  {
    ABC abc = new ABC();
    abc.Foo = new FooHandler(MyFoo);
    abc.InvokeFoo();
  }
}