PRB: Custom ActiveX Property Sheet Entries Are Not Saved

• Microsoft Visual Basic Control Creation and Enterprise Editions, for Windows, version 5.0

SYMPTOMS

ActiveX control property changes entered via a property page are not saved. However, if you enter the properties via the standard property pane that comes with Visual Basic, the changes are saved.

CAUSE

The UserControl needs to explicitly inform the host development environment of any property changes that are made via property pages or are side effects of other property changes.

RESOLUTION

To tell the host development environment of property changes, the UserControl must invoke the PropertyChanged method of the Extender object.

STATUS

This behavior is by design.

MORE INFORMATION

When entering properties via the standard property pane, the host application is setting the properties for your control and, therefore, knows they have been changed.

The host application knows nothing about changes you make via property pages or that there are side effects of other property changes. The user control needs to explicitly tell the host application that properties have been changed, so it can see the changes and save them.

The following example illustrates setting properties:

   ------ in the property page ------

      Private Sub LabelCaption_Changed()
        Changed = True     ' Enable Apply button
      End Sub

      Private Sub ApplyChanges()
      Dim X As Variant
        For Each X In SelectedControls
          X.Caption = LabelCaption.Text
        Next X
      End Sub

   ------ in the user control ------

      Public Property Let Caption(ByVal NewVal As String)
        lblMain.Caption = NewVal
        PropertyChanged "Caption"
      End Sub

REFERENCES

Microsoft Visual Basic Online Help, PropertyChanged Method