Auto complete in Combo Box on Visual Basic .Net

The Windows Forms ComboBox control is used to display data in a drop-down combo box. By default, the ComboBox control appears in two parts: the top part is a text box that allows the user to type a list item. The second part is a list box that displays a list of items from which the user can select one.

‘Sample code on how to create a auto complete box on visual basic .net 

Private Sub cboName_Leave(ByVal sender As Object, ByVal e As System.EventArgs)

Handles cboName.Leave

Dim recRowView As DataRowView

Dim recName As DB.tblNameRow

AutoCompleteCombo_Leave(cboName)

‘OPTIONAL: Now you can do some extra handling if you want

‘Get the Selected Record from my Data Bound Combo (Return Type is DataRowView)

recRowView = cboName.SelectedItem

If recRowView Is Nothing Then Exit Sub

‘Display the Name Info (Row Type comes from my bound Dataset)

recName = recRowView.Row

lblAccountNum.Text = recName.AccountNum

lblCompanyName.Text = recName.CompanyName

End Sub

Private Sub cboName_KeyUp(ByVal sender As Object,

ByVal e As System.Windows.Forms.KeyEventArgs) Handles cboName.KeyUp

AutoCompleteCombo_KeyUp(cboName, e)

End Sub

‘Here are the Generic Functions for handling the events:

Public Sub AutoCompleteCombo_KeyUp(ByVal cbo As ComboBox, ByVal e As KeyEventArgs)

Dim sTypedText As String

Dim iFoundIndex As Integer

Dim oFoundItem As Object

Dim sFoundText As String

Dim sAppendText As String

‘Allow select keys without Autocompleting

Select Case e.KeyCode

Case Keys.Back, Keys.Left, Keys.Right, Keys.Up, Keys.Delete, Keys.Down

Return

End Select

‘Get the Typed Text and Find it in the list

sTypedText = cbo.Text

iFoundIndex = cbo.FindString(sTypedText)

‘If we found the Typed Text in the list then Autocomplete

If iFoundIndex >= 0 Then

‘Get the Item from the list (Return Type depends if Datasource was bound

‘ or List Created)

oFoundItem = cbo.Items(iFoundIndex)

‘Use the ListControl.GetItemText to resolve the Name in case the Combo

‘ was Data bound

sFoundText = cbo.GetItemText(oFoundItem)

‘Append then found text to the typed text to preserve case

sAppendText = sFoundText.Substring(sTypedText.Length)

cbo.Text = sTypedText & sAppendText

‘Select the Appended Text

cbo.SelectionStart = sTypedText.Length

cbo.SelectionLength = sAppendText.Length

End If

End Sub

Public Sub AutoCompleteCombo_Leave(ByVal cbo As ComboBox)

Dim iFoundIndex As Integer

iFoundIndex = cbo.FindStringExact(cbo.Text)

cbo.SelectedIndex = iFoundIndex

End Sub