Hi,

when using a custom editor with the xamPropertyGrid (version 2015.2), the behavior of the PropertyItemValueChanging event looks to be wrong. The default sequence of events are:
- PropertyItemValueChanging raised
- Property updated
- PropertyItemValueChanged raised

When using a custom editor, I get this sequence of events:
- Property updated
- PropertyItemValueChanging raised
- PropertyItemValueChanged raised

i.e. the property is updated prior to the 'changing' event being raised. This is an error according to both the documentation and my understanding of the desired/obvious behavior.

Sample code:

<ig:XamPropertyGrid x:Name="propertyGrid"
                    SelectedObjects="{Binding SelectionManager.Selection, Converter={StaticResource SelectionConverter}}"
                    OptionsMenuVisibility="Collapsed"
                    DescriptionAreaVisibility="Collapsed"
                    FilterAreaVisibility="Collapsed">
  <ig:XamPropertyGrid.EditorDefinitions>
    <ig:PropertyGridEditorDefinition TargetType="system:String">
      <ig:PropertyGridEditorDefinition.EditTemplate>
        <DataTemplate>
          <TextBox Background="LightBlue"
                   Text="{Binding Value, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />
        </DataTemplate>
      </ig:PropertyGridEditorDefinition.EditTemplate>
    </ig:PropertyGridEditorDefinition>
  </ig:XamPropertyGrid.EditorDefinitions>
</ig:XamPropertyGrid>

Regards,
Leif