AutoComplete ComboBox in VB.Net

This is an AutoCompleting ComboBox that works with Data Bound or Regular ComboBoxes in VB.NET. As you type the case is preserved but the remaining text is auto filled by the list items. When the Leave function is called the case is fixed and the index from the list is also selected if there is a matching item.

Call the corresponding functions from your Combobox's KeyUp and Leave events like so:
Collapse

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



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