OBSOLETE: In v19.2+, the List View's Batch Edit mode supports built-in lookup editors for reference properties. The custom code from this example is no longer required.
We continue to enhance DevExpress-related learning materials/examples on GitHub. Unfortunately, this example lacked user interest and its code base is now obsolete.
If the use-case outlined in this example is of importance to you (or if you require additional guidance), please submit a support ticket via the DevExpress Support Center. We will be happy to follow-up.