Private Sub Form_Load()
' Liste füllen
Dim i As Integer
  For i = 0 To 20
    List1.AddItem "Langer Eintrag, der über die Breite der Listbox hinausgeht" & i
  Next i
End Sub
 
Private Sub List1_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
Dim YPos As Integer
Dim OldFontSize As Integer
 
OldFontSize = Me.Font.Size
Me.Font.Size = List1.Font.Size
YPos = Y \ Me.TextHeight("Xyz") + List1.TopIndex
Me.Font.Size = OldFontSize
 
    If YPos < List1.ListCount Then
      List1.ToolTipText = List1.List(YPos)
       Else
      List1.ToolTipText = ""
    End If
End Sub