c# textbox autocomplete dataset ?

Question

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace per
{
    public partial class Form1 : Form
    {

        DataSet1TableAdapters.tblPerTableAdapter dap = new DataSet1TableAdapters.tblPerTableAdapter();

        public Form1()
        {
            InitializeComponent();
        }

        private void groupBox1_Enter(object sender, EventArgs e)
        {

        }

        private void label5_Click(object sender, EventArgs e)
        {

        }

        private void button7_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            openFileDialog1.ShowDialog();
            pictureBox1.ImageLocation = openFileDialog1.FileName;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (dap.GetDataByCode(textBox1.Text).Rows.Count==0)
            {
                dap.Insert(textBox1.Text, textBox2.Text, textBox3.Text, System.IO.File.ReadAllBytes(pictureBox1.ImageLocation), comboBox1.Text, maskedTextBox1.Text, radioButton1.Checked, (int)numericUpDown1.Value, checkBox1.Checked, (int)numericUpDown2.Value, checkBox2.Checked, (int)numericUpDown3.Value, checkBox3.Checked, richTextBox1.Text, textBox4.Text);
                fill();
                temp();
            }
            else
            {
                MessageBox.Show("??? ??? ?????? ?? ????");
                return;
            }
           
        }
            void temp()
            {
                textBox1.Text="";
                textBox2.Text="";
                textBox3.Text="";
                pictureBox1.ImageLocation = System.IO.Path.Combine(Application.StartupPath,"noimage.png");
                comboBox1.SelectedIndex=-1;
                maskedTextBox1.Clear();
                numericUpDown1.Value=0;
                checkBox1.Checked=false;
                numericUpDown2.Value=0;
                checkBox2.Checked=false;
                numericUpDown3.Value=0;
                checkBox3.Checked=false;
                richTextBox1.Clear();
                textBox4.Text="";
            }

            private void button5_Click(object sender, EventArgs e)
            {
                var d = dap.GetDataByCode(textBox1.Text);
                if (d.Rows.Count==0)
                {
                    MessageBox.Show("???? ???? ???? ?????");
                    return;
                }
                dataGridView1.DataSource = d;
                textBox1.Text = d.Rows[0][0].ToString();
                textBox2.Text = d.Rows[0][1].ToString();
                textBox3.Text = d.Rows[0][2].ToString();

                string path = System.IO.Path.Combine(Application.StartupPath + textBox1.Text + ".png");
                System.IO.File.WriteAllBytes(path,(byte[])d.Rows[0]["picper"]);
                pictureBox1.ImageLocation = path;

                comboBox1.Text = d.Rows[0][4].ToString();
                maskedTextBox1.Text = d.Rows[0][5].ToString();

                radioButton1.Checked = !(radioButton1.Checked = (bool)d.Rows[0][6]);

                numericUpDown1.Value = (int)d.Rows[0][7];
                checkBox1.Checked=(bool)d.Rows[0][8];

                numericUpDown2.Value = (int)d.Rows[0][9];
                checkBox2.Checked = (bool)d.Rows[0][10];

                numericUpDown2.Value = (int)d.Rows[0][11];
                checkBox2.Checked = (bool)d.Rows[0][12];

                richTextBox1.Text = d.Rows[0][13].ToString();
                textBox4.Text = d.Rows[0][14].ToString();

                button2.Enabled = false;
                button3.Enabled = true;
                button4.Enabled = true;
            }

            private void button6_Click(object sender, EventArgs e)
            {
                dataGridView1.DataSource = dap.GetData();
                temp();
                button2.Enabled = true;
                button3.Enabled = false;
                button4.Enabled = false;
            }

            private void Form1_Load(object sender, EventArgs e)
            {
                fill();
            }

            void fill()
            {
               
                dataGridView1.DataSource = dap.GetData();

                pictureBox1.ImageLocation = System.IO.Path.Combine(Application.StartupPath, "noimage.png");
           
            }

            private void button3_Click(object sender, EventArgs e)
            {
                if (MessageBox.Show("??? ????? ??????","??? ????",MessageBoxButtons.YesNo,MessageBoxIcon.Question,MessageBoxDefaultButton.Button2)==System.Windows.Forms.DialogResult.Yes)
                {
                    dap.DeleteByCodetblPer(textBox1.Text);
                }
               
                button2.Enabled = true;
                button3.Enabled = false;
                button4.Enabled = false;
            }

            private void button4_Click(object sender, EventArgs e)
            {
                dap.UpdateByCodetblPer(textBox2.Text, textBox3.Text, System.IO.File.ReadAllBytes(pictureBox1.ImageLocation), comboBox1.Text, maskedTextBox1.Text, radioButton1.Checked, (int)numericUpDown1.Value, checkBox1.Checked, (int)numericUpDown2.Value, checkBox2.Checked, (int)numericUpDown3.Value, checkBox3.Checked, richTextBox1.Text, textBox4.Text,textBox1.Text, textBox1.Text);
                button2.Enabled = true;
                button3.Enabled = false;
                button4.Enabled = false;
            }

            private void textBox1_TextChanged(object sender, EventArgs e)
            {
               
            }
           
           
       
    }
}