This method prevents the control from painting until the EndUpdate method is called. The BeginUpdate and EndUpdate methods increases the speed of loading your custom properties , by preventing painting the control when it suffers any change. Once that BeginUpdate method was called, you have to make sure that EndUpdate method will be called too. If a property is added manually, using the Add method, you need to call the Value property each time when you need to refresh the property's value. In case the properties list browses a COM object,  using the Select method,  you need to call the Refresh method to refresh the values for the properties in the browser, in case some changes occurs to the browsed object or if you need to. Also, if a property contains another COM object ( EditObject type ), the Refresh method updates the values for all browsed properties.

The following sample uses the BeginUpdate and EndUpdate methods to lock painting the control while defining the control's properties:

Private Sub Form_Load()
    With PropertiesList1
        .BeginUpdate
            .HeaderVisible = True
            .ColumnCaption(0) = "Property"
            .Select .Object
        .EndUpdate
    End With
End Sub