extends UserControl to create your own control : UserControl « GUI Windows Forms « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. GUI Windows Forms
3. UserControl

using System.Drawing;
using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;

  public class PhoneControl : UserControl
  {    
    public String Phone 
    {      
      get 
      {
        return "("+areaCodeBox.Text+") "+phoneNoBox1.Text+"-" +phoneNoBox2.Text;
      }
    }
    private Label areaCodeLabel;
    private Label phoneNumberLabel;
    private TextBox phoneNoBox1;
    private TextBox phoneNoBox2;
    private TextBox areaCodeBox;
    private System.ComponentModel.Container components = null;

    public PhoneControl()
    {
      this.areaCodeLabel = new Label();
      this.areaCodeBox = new TextBox();
      this.phoneNoBox1 = new TextBox();
      this.phoneNumberLabel = new Label();
      this.phoneNoBox2 = new TextBox();
      this.SuspendLayout();
      // 
      this.areaCodeLabel.Location = new Point(8, 16);
      this.areaCodeLabel.Name = "areaCodeLabel";
      this.areaCodeLabel.Size = new Size(72, 20);
      this.areaCodeLabel.TabIndex = 0;
      this.areaCodeLabel.Text = "Area Code";
      // 
      this.areaCodeBox.Location = new Point(96, 16);
      this.areaCodeBox.MaxLength = 3;
      this.areaCodeBox.Name = "areaCodeBox";
      this.areaCodeBox.Size = new Size(32, 20);
      this.areaCodeBox.TabIndex = 1;
      this.areaCodeBox.Text = "";
      // 
      this.phoneNoBox1.Location = new Point(96, 40);
      this.phoneNoBox1.MaxLength = 3;
      this.phoneNoBox1.Name = "phoneNoBox1";
      this.phoneNoBox1.Size = new Size(32, 20);
      this.phoneNoBox1.TabIndex = 2;
      this.phoneNoBox1.Text = "";
      // 
      this.phoneNumberLabel.Location = new Point(8, 40);
      this.phoneNumberLabel.Name = "phoneNumberLabel";
      this.phoneNumberLabel.Size = new Size(80, 20);
      this.phoneNumberLabel.TabIndex = 2;
      this.phoneNumberLabel.Text = "Phone Number";
      // 
      this.phoneNoBox2.Location = new Point(144, 40);
      this.phoneNoBox2.MaxLength = 4;
      this.phoneNoBox2.Name = "phoneNoBox2";
      this.phoneNoBox2.Size = new Size(40, 20);
      this.phoneNoBox2.TabIndex = 3;
      this.phoneNoBox2.Text = "";
      // 
      this.Controls.Add(this.phoneNoBox2);
      this.Controls.Add(this.phoneNoBox1);
      this.Controls.Add(this.phoneNumberLabel);
      this.Controls.Add(this.areaCodeBox);
      this.Controls.Add(this.areaCodeLabel);
      this.Name = "PhoneControl";
      this.Size = new Size(200, 72);
      this.ResumeLayout(false);
    }
  }
  public class Form1 : Form
  {
    private Button ShowButton;
    private Label PhoneLabel;
    private PhoneControl phoneControl;
    private Label label1;
    private System.ComponentModel.Container components = null;
    public Form1()
    {
      this.phoneControl = new PhoneControl();
      this.ShowButton = new Button();
      this.PhoneLabel = new Label();
      this.label1 = new Label();
      this.SuspendLayout();
      // 
      this.phoneControl.Location = new Point(96, 8);
      this.phoneControl.Name = "phoneControl";
      this.phoneControl.Size = new Size(200, 72);
      this.phoneControl.TabIndex = 0;
      // 
      // ShowButton
      // 
      this.ShowButton.Location = new Point(48, 112);
      this.ShowButton.Name = "ShowButton";
      this.ShowButton.Size = new Size(192, 24);
      this.ShowButton.TabIndex = 1;
      this.ShowButton.Text = "Show Phone No";
      this.ShowButton.Click += new System.EventHandler(this.ShowButton_Click);
      // 
      // PhoneLabel
      // 
      this.PhoneLabel.Location = new Point(8, 168);
      this.PhoneLabel.Name = "PhoneLabel";
      this.PhoneLabel.Size = new Size(272, 24);
      this.PhoneLabel.TabIndex = 2;
      this.PhoneLabel.TextAlign = ContentAlignment.MiddleCenter;
      // 
      // label1
      // 
      this.label1.Location = new Point(8, 0);
      this.label1.Name = "label1";
      this.label1.Size = new Size(80, 80);
      this.label1.TabIndex = 3;
      this.label1.Text = "Phone No:";
      this.label1.TextAlign = ContentAlignment.MiddleCenter;
      // 
      // Form1
      // 
      this.AutoScaleBaseSize = new Size(5, 13);
      this.ClientSize = new Size(292, 197);
      this.Controls.Add(this.label1);
      this.Controls.Add(this.PhoneLabel);
      this.Controls.Add(this.ShowButton);
      this.Controls.Add(this.phoneControl);
      this.Name = "Form1";
      this.Text = "Form1";
      this.ResumeLayout(false);

    }
    [STAThread]
    static void Main() 
    {
      Application.Run(new Form1());
    }
    private void ShowButton_Click(object sender, System.EventArgs e)
    {
      PhoneLabel.Text = phoneControl.Phone;
    }
  }