Aquí hay un código que muestra 7 eventos.
Espero que esto le ayude.
Código:
' Gambas class file
FileChooser1 As FileChooser
VBox1 As VBox
TextArea1 As TextArea
Label1 As Label
Public Sub Form_Open()
  With Me
    .Arrangement = Arrange.Horizontal
    .Padding = 5
    .H = 490
    .W = 1000
  End With
  With FileChooser1 = New FileChooser(Me) As "FileChooser1"
    .ShowButton = True
    .Expand = True
  End With
  With VBox1 = New VBox(Me)
    .Expand = True
  End With
  With TextArea1 = New TextArea(VBox1) As "TextArea1"
    .Expand = True
  End With
  With Label1 = New Label(VBox1) As "Label1"
    .Font.Bold = True
    .Alignment = Align.Center
    .Font.Size = 16
    .H = 28
  End With
End
Public Sub FileChooser1_Activate()
  TextArea1.Text &= "Activate" & gb.Newline
End
Public Sub FileChooser1_Arrange()
  TextArea1.Text &= "Arrange" & gb.Newline
End
Public Sub FileChooser1_BeforeArrange()
  TextArea1.Text &= "BeforeArrange" & gb.Newline
End
Public Sub FileChooser1_Cancel()
  TextArea1.Text &= "Cancel" & gb.Newline
End
Public Sub FileChooser1_Change()
  TextArea1.Text &= "Change" & gb.Newline
End
Public Sub FileChooser1_Enter()
  Label1.Text = "Enter"
End
Public Sub FileChooser1_Leave()
  Label1.text = "Leave"
End