Refreshing the PropertyGrid

[rbulph]

I have three alternative bits of code that I can use to refresh the property grid when a property changes other than through the user changing it through the propertygrid. These are shown below:

 

Public Class Form1
   Dim WithEvents h As New ABC

   Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
       Me.PropertyGrid1.SelectedObject = h
   End Sub

   Private Sub h_paintgrid() Handles h.paintgrid
       Me.PropertyGrid1.Refresh()
   End Sub
End Class
Public Class ABC

   Event paintgrid()
   Private def As Long
   <System.ComponentModel.RefreshProperties(System.ComponentModel.RefreshProperties.Repaint)> Public Property Def1() As Long
       'Option 1 = RefreshProperties.Repaint,   Option 2 = RefreshProperties.All
       Get
           Return def
       End Get
       Set(ByVal value As Long)
           def = value
           Me.Ghi1 = value & " *!$@"
           '   RaiseEvent paintgrid()  'Option 3
       End Set
   End Property

   Private ghi As String
   Public Property Ghi1() As String
       Get
           MsgBox("Property Queried")
           Return ghi
       End Get
       Friend Set(ByVal value As String)
           ghi = value
       End Set

   End Property

   Private jkl As Boolean
   Public Property Jkl1() As Boolean
       Get
           Return jkl
       End Get
       Set(ByVal value As Boolean)
           jkl = value
       End Set
   End Property

End Class

 

Each of them works OK to refresh the value shown for Ghi1 when Def1 is changed in the propertygrid and the focus is then moved away from Def1 (to Jkl1 for instance). But I have three questions:

 

1. Is there really any difference between Options 1 and 2? The help files say that RefreshProperties.All means that the properties will be requeried. But I get my message box even if RefreshProperties.Repaint is set and cannot see any difference between the two options.

2. Is there any argument against just using my event based Option 3 approach? I find this the simplest; and

3. Is there any way of just having the Ghi1 item refreshed in the propertygrid rather than the whole grid being refreshed each time? That would seem more efficient, if it can be done, especially in a larger grid.

 

EDIT: Option 3 seems to be better in fact because RefreshProperties only operates if the change is made by the user through the propertygrid, not if I make a change in code.

Edited December 5, 2006 by rbulph