AutoComplete Textbox in Windows Application C#.Net

To implement the AutoComplete Textbox in Windows form C#.net  you need to follow the below steps :

Step1 :
First you need to design a table in Ms Access 2007  to retrieve the records from database.

Step2:
On the File menu, click New Project. Select Windows Forms Application as your project type.
Design the Form using controls from Toolbox.

Step3:
Now open the Form.cs page and write the following source code

 Form.cs Code :

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms; 

using System.Data.OleDb;

namespace Autocomplete

{

    public partial class Autocomplete_TextBox : Form

    {

        OleDbConnection con = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\App_Data\SampleDB.accdb; Jet OLEDB:Database Password=1234;Persist Security Info=False");

        AutoCompleteStringCollection namesCollection = new AutoCompleteStringCollection();

        public AmirAds_MailSend()

        {

            InitializeComponent();

        }

         private void Autocomplete_TextBox_Load(object sender, EventArgs e)

        {

            con.Open();

            OleDbCommand cmd = new OleDbCommand("Select distinct Email_Id from Sample_CreateClient order by Email_Id asc", con);

            cmd.CommandType = CommandType.Text;

            OleDbDataReader dr;

            dr= cmd.ExecuteReader();

            if (dr.HasRows == true)

            {

                while (dr.Read())

                    namesCollection.Add(dr["Email_Id"].ToString());

            }

            con.Close();

            txtToMail.AutoCompleteMode = AutoCompleteMode.Suggest;

            txtToMail.AutoCompleteSource = AutoCompleteSource.CustomSource;

            txtToMail.AutoCompleteCustomSource = namesCollection;

        }

    }

}

  
Step4:
Now build the Solution and Debug it for the output.