Question

I’m working on VS 2010 with VB using .NET Framework 4.0

I have a combobox. It has some items in it and displays just fine. Here’s where it gets a little weird:

If I click the drop-down arrow on the combobox and CLICK on the item I want, SelectedIndexChanged is called – good.

If I click inside the text area of the combobox and start typing what I want selected and finish it by pressing the up (or down) key, SelectedIndexChanged is called – also good.

If I click the drop-down arrow on the combobox and start typing what I want selected and finish it by pressing ENTER, SelectedIndexChanged is not called – PROBLEM.

Is there a different event that is caused by the ENTER in the last case? I’ve tried using the TextChanged and TextUpdate events, but those do not seem to be working:

Private Sub cmbStatus_TextChanged(sender As System.Object, e As System.EventArgs) Handles cmbStatus.TextChanged
If e.Equals(Keys.Enter) Then
    Call SomeMethod()
End If

Should I use something besides e.Equals(Keys.Enter)?

Is there another event I should be looking for?

EDIT:
An example of the items in the ComboBox are:

• 10 – NEW ENTRY AND COMPLETENESS CHECK ---> this is the most common type
• 13 – ASSIGNED TO TRB/HRB ---> there are a few with '/'
• 60 – EXTERNAL (HOLD UNTIL FURTHER NOTICE) ---> there are a few with '(' and ')'

Basically, the type of each listing is “## – SOME TEXT”.

Answer 1

Option Strict On
Public Class Form1
    Friend WithEvents ComboBox1 As New ComboBox With {.Parent = Me}
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
        ComboBox1.Items.AddRange({"hello", "tes1ted", "word", "item", "tes2ted"})
        ComboBox1.Text = ComboBox1.Items(0).ToString
    End Sub
    Private Sub ComboBox1_KeyUp(ByVal sender As Object, ByVal e As KeyEventArgs) Handles ComboBox1.KeyUp
        'You can put this in the keydown event, or adapt it a small bit and put it in the keypress event
        'putting it in the textchanged event is problematic and not recommended.
        Dim OriginalText As String = ComboBox1.Text
        If e.KeyCode = Keys.Enter Then
            If ComboBox1.SelectionLength > 0 Then
                ComboBox1.Text = ComboBox1.Text
                ComboBox1.SelectionLength = 0
                ComboBox1.SelectionStart = ComboBox1.Text.Length
            End If
        End If
        If Not IsTextKey(e.KeyCode) Then Exit Sub
        Dim Filter As String = ComboBox1.Text & "*"
        If Filter.Length = 1 Then Exit Sub
        For I = 0 To ComboBox1.Items.Count - 1
            If LCase(ComboBox1.Items(I).ToString) Like LCase(Filter) Then
                ComboBox1.SelectedItem = ComboBox1.Items(I)
                ComboBox1.Select(OriginalText.Length, (ComboBox1.Text.Length - OriginalText.Length))
                Exit Sub
            End If
        Next
    End Sub
    Function IsTextKey(ByVal Key As Integer) As Boolean
        Select Case True
            Case Key = Keys.Up : Return False
            Case Key = Keys.Down : Return False
            Case Key = Keys.Left : Return False
            Case Key = Keys.Right : Return False
            Case Key = Keys.Back : Return False
            Case Key = Keys.Delete : Return False
            Case Key = Keys.LWin : Return False
            Case Key = Keys.RWin : Return False
                'add whatever I missed
                'return false if the key either removes text from the textbox 
                'or does not produce a character
            Case Else
                'return true if the key produces a visible character(including space)
                Return True
        End Select
    End Function
End Class