How to get the AutoComplete on matching part of any string in the ComboBoxAdv items?

5 mins read

AutoComplete enables the AutoComplete behavior in the ComboBoxAdv. The AutoComplete on matching any part of the string in the ComboBoxAdv items with its text input can be achieved by using its TextChanged event.

The following code example demonstrates the same.

//Creates DataTable
DataTable dataTable = new DataTable();
// Creates a DataView.
DataView listDataView;
bool isTextCleared = true;
string rowFilterText = string.Empty;
// Adds Columns.
dataTable.Columns.Add("FirstName");
dataTable.Columns.Add("LastName");
dataTable.Columns.Add("occupation");
dataTable.Columns.Add("place");
// Creates a Data Set.
DataSet dataSet = new DataSet();
dataSet.Tables.Add(dataTable);
dataTable.Rows.Add(new string[] { "John", "Tina", "Doctor", "Alaska" });
dataTable.Rows.Add(new string[] { "Mary", "Anu", "Teacher", "China" });
dataTable.Rows.Add(new string[] { "Asha", "Roy", "Staff", "London" });
dataTable.Rows.Add(new string[] { "George", "Gaskin", "Nurse", "Germany" });
dataTable.Rows.Add(new string[] { "Sam", "Jens", "Engineer", "Russia" });
dataTable.Rows.Add(new string[] { "Ben", "Geo", "Developer", "India" });
// Creates a DataView.
DataView dataView = new DataView(dataTable);
// Sets DataSource.
this.comboBoxAdv1.DataSource = dataView;
// Sets DisplayMember.
this.comboBoxAdv1.DisplayMember = "place";
//Disables the AutoComplete behavior
this.comboBoxAdv1.AutoComplete = false;
void comboBoxAdv1_TextChanged(object sender, EventArgs e)
{
    text = this.comboBoxAdv1.Text;
    if (this.comboBoxAdv1.Text == string.Empty && !isTextCleared)
    {
        this.comboBoxAdv1.DataSource = dataTable;
        isTextCleared = true;
    }
    else if (this.comboBoxAdv1.Text != string.Empty && isTextCleared)
    {
        //Gets the filter text
        rowFilterText = "[" + dataTable.Columns[dataTable.Columns[this.comboBoxAdv1.DisplayMember].Ordinal].ColumnName + "]" + " LIKE '" + "%" + this.comboBoxAdv1.Text + "%'";
        listDataView = new DataView(this.dataTable, rowFilterText, null, DataViewRowState.CurrentRows);
        if (listDataView.Count > 0)
        {
            //Gets the data source of the ComboBoxAdv
            this.comboBoxAdv1.DataSource = listDataView;
            this.comboBoxAdv1.SelectionStart = 0;
            this.comboBoxAdv1.SelectionLength = this.comboBoxAdv1.Text.Length;
            comboBoxAdv1.DroppedDown = true;
            return;
        }
        else
        {
            comboBoxAdv1.DroppedDown = false;
            comboBoxAdv1.SelectionStart = this.comboBoxAdv1.Text.Length;
        }
    }
}

'Creates DataTable
Private dataTable As New DataTable()
'Creates a DataView.
Private listDataView As DataView
Private isTextCleared As Boolean = True
Private rowFilterText As String = String.Empty
'Adds Columns.
dataTable.Columns.Add("FirstName")
dataTable.Columns.Add("LastName")
dataTable.Columns.Add("occupation")
dataTable.Columns.Add("place")
'Creates a Data Set.
Dim dataSet As New DataSet()
dataSet.Tables.Add(dataTable)
dataTable.Rows.Add(New String() { "John", "Tina", "Doctor", "Alaska" })
dataTable.Rows.Add(New String() { "Mary", "Anu", "Teacher", "China" })
dataTable.Rows.Add(New String() { "Asha", "Roy", "Staff", "London" })
dataTable.Rows.Add(New String() { "George", "Gaskin", "Nurse", "Germany" })
dataTable.Rows.Add(New String() { "Sam", "Jens", "Engineer", "Russia" })
dataTable.Rows.Add(New String() { "Ben", "Geo", "Developer", "India" })
'Creates a DataView.
Dim dataView As New DataView(dataTable)
'Sets DataSource.
Me.comboBoxAdv1.DataSource = dataView
'Sets DisplayMember.
Me.comboBoxAdv1.DisplayMember = "place"
'Disables the AutoComplete behavior
Me.comboBoxAdv1.AutoComplete = False
Private Sub comboBoxAdv1_TextChanged(ByVal sender As Object, ByVal e As EventArgs)
 text = Me.comboBoxAdv1.Text
 If Me.comboBoxAdv1.Text = String.Empty AndAlso (Not isTextCleared) Then
  Me.comboBoxAdv1.DataSource = dataTable
  isTextCleared = True
 ElseIf Me.comboBoxAdv1.Text <> String.Empty AndAlso isTextCleared Then
  'Gets the filter text
  rowFilterText = "[" & dataTable.Columns(dataTable.Columns(Me.comboBoxAdv1.DisplayMember).Ordinal).ColumnName & "]" & " LIKE '" & "%" & Me.comboBoxAdv1.Text & "%'"
  listDataView = New DataView(Me.dataTable, rowFilterText, Nothing, DataViewRowState.CurrentRows)
  If listDataView.Count > 0 Then
   'Gets the data source of the ComboBoxAdv
   Me.comboBoxAdv1.DataSource = listDataView
   Me.comboBoxAdv1.SelectionStart = 0
   Me.comboBoxAdv1.SelectionLength = Me.comboBoxAdv1.Text.Length
   comboBoxAdv1.DroppedDown = True
   Return
  Else
   comboBoxAdv1.DroppedDown = False
   comboBoxAdv1.SelectionStart = Me.comboBoxAdv1.Text.Length
  End If
 End If
End Sub

Before selection:

Before selection