You'll need to do a bit more but here's a good start:
vb.net Code:
  1. Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyDown
  2.     e.SuppressKeyPress = True
  3.  
  4.     Dim parts As New List(Of String)
  5.  
  6.     If e.Control Then
  7.         parts.Add("Ctrl")
  8.     End If
  9.  
  10.     If e.Shift Then
  11.         parts.Add("Shift")
  12.     End If
  13.  
  14.     If e.Alt Then
  15.         parts.Add("Alt")
  16.     End If
  17.  
  18.     Select Case e.KeyCode
  19.         Case Keys.ControlKey, Keys.ShiftKey, Keys.Menu
  20.             'Ignore modifier keys alone.
  21.         Case Else
  22.             parts.Add(e.KeyCode.ToString())
  23.     End Select
  24.  
  25.     Me.TextBox1.Text = String.Join(" + ", parts)
  26.  
  27. End Sub