How to: Access Nested List View or Master Detail View Environment (ASP.NET Core Blazor and Windows Forms)

• Jul 09, 2025
• 5 minutes to read

This topic explains how to use Controllers to access a nested List View‘s or a master Detail View‘s environment (Frames, Controllers, Actions, Objects) in XAF ASP.NET Core Blazor and Windows Forms applications.

The topic describes two scenarios:

• How to: Access a Master Detail View’s Environment from a Nested List View Controller
• How to: Access a Nested List View’s Environment from a Master Detail View Controller

This topic uses an Employee Detail View and Tasks nested List View. You can find the corresponding Employee and DemoTask business classes in the XAF MainDemo application (%PUBLIC%\Documents\DevExpress Demos 25.2\Components\XAF\MainDemo.NET.EFCore).

ASP.NET Core Blazor Windows Forms

Note

XAF creates nested List Views for collection properties. These properties are often used in relationships between persistent objects.

How to: Access a Master Detail View’s Environment from a Nested List View Controller

Choose the method most suitable for your scenario:

• Access a Master Detail View’s Frame and its Controllers
• Access a Master Detail View’s Current Object (the View Item Approach)
• Access a Master Detail View’s Current Object (the Property Collection Source Approach)

If you need to access the master View from the DashboardViewItem or the DetailPropertyEditor, use the Access a Master Detail View’s Frame and its Controllers approach. See the E4916 article for an example.

Access a Master Detail View’s Frame and its Controllers

1. In the required project of your application, create a nested List View Controller that receives the parent Frame in the AssignMasterFrame method. Use this Frame to customize its Controllers and Actions. For more information, refer to the following topic: Customize Controllers and Actions.

2. In the required project of your application, create a master Detail View Controller that acquires the Detail View Frame and passes it to the NestedListViewFrameController. Use the ListPropertyEditor.FrameChanged event subscription to ensure the nested List View exists.

Access a Master Detail View’s Current Object (the View Item Approach)

1. In the required project of your application, create a nested List View Controller. Use the CurrentObjectChanged event to update the master Detail View Caption each time the CurrentObject changes.

Access a Master Detail View’s Current Object (the Property Collection Source Approach)

1. In the required project of your application, create a nested List View Controller. The nested List View’s CollectionSource type is PropertyCollectionSource because the List View is a collection property.

2. Handle the MasterObjectChanged event and process the current MasterObject when the master object changes.

How to: Access a Nested List View’s Environment from a Detail View Controller

1. In the required project of your application, create a Detail View Controller.

2. Handle the CurrentObjectChanged event and use the CustomizeViewItemControl<T>(DetailView, Controller, Action<T>, String[]) method to obtain the current nested List View‘s Frame and object. For more information about the use of PerformLogicWithCurrentListViewObject and PerformLogicInNestedListViewController methods, refer to the following topic: Customize Controllers and Actions.

See Also

Ways to Access UI Elements and Their Controls