AutoComplete TextBox In WinForms Windows Forms Application

In this example i am explaining how to create AutoComplete TextBox In WinForms Windows Forms Application Using C# VB.NET. There are two ways we can use Autocomplete feature

1. Auto complete with previously entered text in textbox.

2. AutoComplete TextBox by fetching data from database.

Read Ajax AutoComplete Extender Textbox for asp.net web applications.

1. Auto complete textBox with previously entered text in textbox.

For filling textbox with previously entered data/text in textbox using Autocomplete feature we can implement by setting autocomplete mode proeprty of textbox to suggest, append or sugestappend and setting autocomplete source to custom source progrmetically

First of all create a global AutoCompleteStringCollection and write code like this

namespace WindowsApplication1
{
public partial class Form1 : Form
{
AutoCompleteStringCollection autoComplete = new AutoCompleteStringCollection();
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
autoComplete.Add(textBox1.Text);
MessageBox.Show("hello");
}

private void Form1_Load(object sender, EventArgs e)
{
textBox1.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
textBox1.AutoCompleteSource = AutoCompleteSource.CustomSource;
//auto.Add(textBox1.Text);
textBox1.AutoCompleteCustomSource = autoComplete;
}
}
}

2. AutoComplete textBox by fetching the data from database.

For this i've created a database with a table containing names which will be shown in textbox as suggestions, for this we need to create a AutoCompleteStringCollection and then add the records in this collection using datareader to fetch records from database

For autocomplete functionalty to work we need to define these 3 properties of textbox

1. AutoCompleteMode - we can choose either suggest or appned or suggestappend as names are self explanatory

2. AutoCompleteSource - this needs to be set as Custom Source

3. AutoCompleteCustomSource - this is the collection we created earlier

The complete C# code will look like this

namespace AutoCompleteTextBox
{

public partial class frmAuto : Form
{
public string strConnection =
ConfigurationManager.AppSettings["ConnString"];
AutoCompleteStringCollection namesCollection =
new AutoCompleteStringCollection();
public frmAuto()
{
InitializeComponent();
}

private void frmAuto_Load(object sender, EventArgs e)
{
SqlDataReader dReader;
SqlConnection conn = new SqlConnection();
conn.ConnectionString = strConnection;
SqlCommand cmd = new SqlCommand();
cmd.Connection = conn;
cmd.CommandType = CommandType.Text;
cmd.CommandText =
"Select distinct [Name] from [Names]" +
" order by [Name] asc";
conn.Open();
dReader = cmd.ExecuteReader();
if (dReader.HasRows == true)
{
while (dReader.Read())
namesCollection.Add(dReader["Name"].ToString());

}
else
{
MessageBox.Show("Data not found");
}
dReader.Close();

txtName.AutoCompleteMode = AutoCompleteMode.Suggest;
txtName.AutoCompleteSource = AutoCompleteSource.CustomSource;
txtName.AutoCompleteCustomSource = namesCollection;

}
private void btnCancel_Click(object sender, EventArgs e)
{
Application.Exit();
}
private void btnOk_Click(object sender, EventArgs e)
{
MessageBox.Show("Hope you like this example");
}

}
}

In the similar way we can also create a autocomplete type combobox

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