Csharp/C Sharp/Components/ComboBox

Auto Complete ComboBox

  using System;
  using System.Drawing;
  using System.Collections;
  using System.ruponentModel;
  using System.Windows.Forms;
  using System.Data;
  public class Form1 : System.Windows.Forms.Form
  {
    private AutoCompleteComboBox combo; 
    public Form1()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      combo = new AutoCompleteComboBox();
      combo.Location = new System.Drawing.Point(64, 32);
      combo.Size = new System.Drawing.Size(150, 20);
            combo.Items.Add("Aaaaaa");
            combo.Items.Add("Bbbbbbbbb");
            combo.Items.Add("Ccccccccccc");
      
      Controls.Add(combo);
      CenterToScreen();
    }
    static void Main() 
    {
      Application.Run(new Form1());
    }
  }
    
    public class AutoCompleteComboBox : System.Windows.Forms.ruboBox
    {
        public event System.ruponentModel.CancelEventHandler NotInList;
        private bool strict = true;
        private bool isEditing = false;
        public AutoCompleteComboBox() : base() {
        }
        public bool Strict
        {
            get { return strict; }
            set { strict = value; }
        }
        protected virtual void OnNotInList(System.ruponentModel.CancelEventArgs e)
        {
            if (NotInList != null)
            {
                NotInList(this, e);
            }
        }   
        protected override void OnTextChanged(System.EventArgs e)
        {
            if (isEditing)
            {
                string input = Text;
                int index = this.FindString(input);
                if (index >= 0)
                {
                    isEditing = false;
                    SelectedIndex = index;
                    isEditing = true;
                    Select(input.Length, Text.Length);
                }
            }
            base.OnTextChanged(e);
        }
        protected override void OnValidating(System.ruponentModel.CancelEventArgs e)
        {
            if (this.Strict)
            {
                int pos = this.FindStringExact(this.Text);
        
                if (pos == -1)
                {
                    OnNotInList(e);
                }
                else
                {
                    this.SelectedIndex = pos;
                }
            }
            base.OnValidating(e);
        }
        protected override void OnKeyDown(System.Windows.Forms.KeyEventArgs e)
        {
            isEditing = (e.KeyCode != Keys.Back && e.KeyCode != Keys.Delete);
            base.OnKeyDown(e);
        }
    }

Buildin AutoCompleteMode for ComboBox

using System;
using System.Collections.Generic;
using System.ruponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
public class Form1 : Form
{
    private System.Windows.Forms.ruboBox lstColors;
  public Form1() {
        InitializeComponent();
        string[] colorNames;
        colorNames = System.Enum.GetNames(typeof(KnownColor));
        lstColors.Items.AddRange(colorNames);
  }
    private void InitializeComponent()
    {
        this.lstColors = new System.Windows.Forms.ruboBox();
        this.SuspendLayout();
        this.lstColors.AutoCompleteMode = ((System.Windows.Forms.AutoCompleteMode)((System.Windows.Forms.AutoCompleteMode.Suggest | System.Windows.Forms.AutoCompleteMode.Append)));
        this.lstColors.AutoCompleteSource = System.Windows.Forms.AutoCompleteSource.ListItems;
        this.lstColors.FormattingEnabled = true;
        this.lstColors.Location = new System.Drawing.Point(13, 13);
        this.lstColors.Name = "lstColors";
        this.lstColors.Size = new System.Drawing.Size(267, 21);
        this.lstColors.TabIndex = 0;
        this.AutoScaleBaseSize = new System.Drawing.Size(5, 14);
        this.ClientSize = new System.Drawing.Size(296, 82);
        this.Controls.Add(this.lstColors);
        this.Font = new System.Drawing.Font("Tahoma", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
        this.Name = "Form1";
        this.Text = "AutoComplete";
        this.ResumeLayout(false);
    }
  [STAThread]
  static void Main()
  {
    Application.EnableVisualStyles();
    Application.Run(new Form1());
  }
}

Use an Autocomplete Combo Box

using System;
using System.Windows.Forms;
using System.Drawing;
public class AutoCompleteComboBoxTest : System.Windows.Forms.Form {
   public AutoCompleteComboBoxTest(){
        AutoCompleteComboBox combo = new AutoCompleteComboBox();
        combo.Location = new Point(10,10);
        this.Controls.Add(combo);
        combo.Items.Add("Aaaaaa");
        combo.Items.Add("Bbbbbbbbb");
        combo.Items.Add("Ccccccccccc");
   }
   public static void Main(){
       Application.Run(new AutoCompleteComboBoxTest());
   } 
}

public class AutoCompleteComboBox : ComboBox {
    private bool controlKey = false;
    protected override void OnKeyPress( System.Windows.Forms.KeyPressEventArgs e) {
        base.OnKeyPress(e);
        if (e.KeyChar == (int)Keys.Escape) {
            this.SelectedIndex = -1;
            this.Text = "";
            controlKey = true;
        } else if (Char.IsControl(e.KeyChar)) {
            controlKey = true;
        } else {
            controlKey = false;
        }
    }
    protected override void OnTextChanged(System.EventArgs e) {
        base.OnTextChanged(e);
        if (this.Text != "" && !controlKey) {
            string matchText = this.Text;
            int match = this.FindString(matchText);
            if (match != -1) {
                this.SelectedIndex = match;
                this.SelectionStart = matchText.Length;
                this.SelectionLength = this.Text.Length - this.SelectionStart;
            }
        }
    }
}