Implement AutoComplete TextBox inside Windows Form DataGridView using C# and VB.Net

Hi SUJAYS,

Check this example. Now please take its reference and correct your code.

Database

For this example I have used of Northwind database that you can download using the link given below.

Download Northwind Database

Namespaces

C#

using System.Data;
using System.Data.SqlClient;

VB.Net

Imports System.Data
Imports System.Data.SqlClient

Code

C#

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

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

    private void OnEditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
    {
        if (dataGridView1.Columns[1].HeaderText.Equals("Name"))
        {
            TextBox textBox = e.Control as TextBox;
            if (textBox != null)
            {
                textBox.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
                textBox.AutoCompleteSource = AutoCompleteSource.CustomSource;
                textBox.AutoCompleteCustomSource = AutoCompleteItems();
            }
        }
    }

    private void BindDataGrid()
    {
        string constring = @"Server=.\SQL2014;DataBase=Northwind;UID=sa;PWD=pass@123";
        using (SqlConnection con = new SqlConnection(constring))
        {
            using (SqlCommand cmd = new SqlCommand("SELECT TOP 10 * FROM Customers", con))
            {
                cmd.CommandType = CommandType.Text;
                using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
                {
                    using (DataTable dt = new DataTable())
                    {
                        sda.Fill(dt);
                        dataGridView1.AutoGenerateColumns = false;
                        dataGridView1.ColumnCount = 3;
                        dataGridView1.Columns[0].Name = "Id";
                        dataGridView1.Columns[0].HeaderText = "Id";
                        dataGridView1.Columns[0].DataPropertyName = "CustomerID";

                        dataGridView1.Columns[1].Name = "Name";
                        dataGridView1.Columns[1].HeaderText = "Name";
                        dataGridView1.Columns[1].DataPropertyName = "ContactName";

                        dataGridView1.Columns[2].Name = "Country";
                        dataGridView1.Columns[2].HeaderText = "Country";
                        dataGridView1.Columns[2].DataPropertyName = "Country";
                        dataGridView1.DataSource = dt;
                    }
                }
            }
        }
    }

    public AutoCompleteStringCollection AutoCompleteItems()
    {
        AutoCompleteStringCollection acsc = new AutoCompleteStringCollection();
        string conString = @"Server=.\SQL2014;DataBase=Northwind;UID=sa;PWD=pass@123";
        string query = "SELECT DISTINCT Country FROM Customers WHERE Country IS NOT NULL";
        using (SqlConnection con = new SqlConnection(conString))
        {
            SqlCommand cmd = new SqlCommand(query, con);
            con.Open();
            SqlDataReader sdr = cmd.ExecuteReader();
            while (sdr.Read())
            {
                acsc.Add(sdr["Country"].ToString());
            }
            con.Close();
        }

        return acsc;
    }
}

VB.Net

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        BindDataGrid()
    End Sub

    Private Sub OnEditingControlShowing(ByVal sender As Object, ByVal e As DataGridViewEditingControlShowingEventArgs) Handles dataGridView1.EditingControlShowing
        If dataGridView1.Columns(1).HeaderText.Equals("Name") Then
            Dim textBox As TextBox = TryCast(e.Control, TextBox)
            If textBox IsNot Nothing Then
                textBox.AutoCompleteMode = AutoCompleteMode.SuggestAppend
                textBox.AutoCompleteSource = AutoCompleteSource.CustomSource
                textBox.AutoCompleteCustomSource = AutoCompleteItems()
            End If
        End If
    End Sub

    Private Sub BindDataGrid()
        Dim constring As String = "Server=.\SQL2014;DataBase=Northwind;UID=sa;PWD=pass@123"
        Using con As SqlConnection = New SqlConnection(constring)
            Using cmd As SqlCommand = New SqlCommand("SELECT TOP 10 * FROM Customers", con)
                cmd.CommandType = CommandType.Text
                Using sda As SqlDataAdapter = New SqlDataAdapter(cmd)
                    Using dt As DataTable = New DataTable()
                        sda.Fill(dt)
                        dataGridView1.AutoGenerateColumns = False
                        dataGridView1.ColumnCount = 3
                        dataGridView1.Columns(0).Name = "Id"
                        dataGridView1.Columns(0).HeaderText = "Id"
                        dataGridView1.Columns(0).DataPropertyName = "CustomerID"
                        dataGridView1.Columns(1).Name = "Name"
                        dataGridView1.Columns(1).HeaderText = "Name"
                        dataGridView1.Columns(1).DataPropertyName = "ContactName"
                        dataGridView1.Columns(2).Name = "Country"
                        dataGridView1.Columns(2).HeaderText = "Country"
                        dataGridView1.Columns(2).DataPropertyName = "Country"
                        dataGridView1.DataSource = dt
                    End Using
                End Using
            End Using
        End Using
    End Sub

    Public Function AutoCompleteItems() As AutoCompleteStringCollection
        Dim acsc As AutoCompleteStringCollection = New AutoCompleteStringCollection()
        Dim conString As String = "Server=.\SQL2014;DataBase=Northwind;UID=sa;PWD=pass@123"
        Dim query As String = "SELECT DISTINCT Country FROM Customers WHERE Country IS NOT NULL"
        Using con As SqlConnection = New SqlConnection(conString)
            Dim cmd As SqlCommand = New SqlCommand(query, con)
            con.Open()
            Dim sdr As SqlDataReader = cmd.ExecuteReader()
            While sdr.Read()
                acsc.Add(sdr("Country").ToString())
            End While
            con.Close()
        End Using

        Return acsc
    End Function
End Class

Screenshot