Devexpress Xaf Views

DevExpress XAF — Views

Views are the primary UI elements in XAF that display data. XAF auto-generates Views from the Application Model and business classes.

Prerequisites & Installation

Views are part of the core XAF framework — no additional module registration is required.

NuGet Packages (already included in XAF projects)

Where to Place View-Related Code

Using Statements

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using DevExpress.ExpressApp;           // ListView, DetailView, DashboardView, ShowViewParameters
using DevExpress.Persistent.Base;      // DefaultClassOptionsAttribute, NavigationItemAttribute
using DevExpress.ExpressApp.SystemModule; // NavigationItemNodeGenerator, ShowNavigationItemController

Key Namespaces

ORM Detection

XPO vs EF Core affects default data access mode selection. Both ORMs support all 7 data access modes. When XPO is detected, the XPO-specific cast ((XPObjectSpace)objectSpace).Session is used inside views/controllers to access the underlying Session.

View Type Hierarchy

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View (abstract)
├── CompositeView (abstract, contains ViewItems)
│   ├── DashboardView       — displays multiple Views side-by-side
│   └── ObjectView (abstract)
│       ├── DetailView      — displays a single object
│       └── ListView        — displays a collection of objects

Creating Views Programmatically

Refer to references/creating-views.md

When you need to:

• Create a ListView from type via Application.CreateListView(IObjectSpace, Type, bool) or with a CollectionSourceBase overload
• Create a DetailView with isRoot controlling Save/Cancel visibility and ObjectSpace lifecycle
• Create a DashboardView by ID via Application.CreateDashboardView
• Understand FindListViewId and CreateCollectionSource for custom list view setup
• Create non-persistent object views with NonPersistentObjectSpace
• Always create a dedicated ObjectSpace per new view — do not reuse this.ObjectSpace from the controller

Showing Views

Refer to references/showing-views.md

When you need to:

• Show a view from an Action handler via ShowViewParameters (CreatedView, TargetWindow, Context, Controllers collection)
• Call Application.ShowViewStrategy.ShowView(svp, new ShowViewSource(Frame, null)) for programmatic display
• Create a PopupWindowShowAction with CustomizePopupWindowParams and selection handling
• Show a popup without an Action via Application.ShowViewStrategy.ShowViewInPopupWindow (modal popup shortcut)
• Replace the current view in the existing frame with Frame.SetView(view) — lower-level than ShowViewStrategy, used for programmatic in-frame navigation

TargetWindow Options

Navigation

Add to Navigation via Attributes

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// Adds to "Default" navigation group, registers default List and Detail views, adds navigation item
[DefaultClassOptions]
public class Contact : BaseObject { }

// Adds to specific navigation group (group created automatically if it does not exist)
[NavigationItem("Management")]
public class Employee : BaseObject { }

Programmatic Navigation Item Addition

Add navigation items in code via ModelNodesGeneratorUpdater<NavigationItemNodeGenerator> (from DevExpress.ExpressApp.SystemModule), registered in ModuleBase.AddGeneratorUpdaters. See references/layout-and-dashboards.md for the full example.

View.IsRoot

Controls whether Save/Cancel Actions are shown:

• IsRoot = true — View creates its own dedicated ObjectSpace, shows Save/Cancel buttons, and manages its own persistence lifecycle
• IsRoot = false — View shares an ancestor view's ObjectSpace and its changes are committed when that root view saves

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// Popup with its own Save button
DetailView view = Application.CreateDetailView(os, contact, isRoot: true);

// Embedded view that saves with parent
DetailView view = Application.CreateDetailView(os, contact, isRoot: false);

Accessing View Data

Refer to references/view-data-access.md

When you need to:

• Access the current object via View.CurrentObject (null for empty List Views) or strongly typed ViewCurrentObject
• Subscribe to CurrentObjectChanged or SelectionChanged events
• Get selected objects from a ListView via SelectedObjects (IList) or e.SelectedObjects in Action handlers
• Apply named (keyed) filter criteria to ListView.CollectionSource.Criteria
• Sort via CollectionSource.Sorting and force reload with CollectionSource.ResetCollection()

List View Data Access Modes

Set via IModelListView.DataAccessMode (CollectionSourceDataAccessMode enum, namespace DevExpress.ExpressApp) in code using a ModelNodesGeneratorUpdater. DefaultListViewOptionsAttribute does not have a DataAccessMode property.

EF Core vs XPO: All 7 modes are available for both EF Core and XPO — no modes are exclusive to a single ORM. Default for all regular List Views is Client; Queryable is the default only for ASP.NET Core Blazor Tree List Views and Lookup List Views, regardless of ORM.

List View Modes & Editing

Refer to references/listview-modes.md

When you need to:

• Set data access mode via ModelNodesGeneratorUpdater (not via DefaultListViewOptionsAttribute)
• Enable in-place editing via [DefaultListViewOptions(true, NewItemRowPosition.None)] positional constructor or controller-side View.AllowEdit.SetItemValue("key", true) (AllowEdit is a BoolList, not a simple bool)
• Configure split layout (MasterDetailMode) to show ListView and DetailView side-by-side
• Set SplitLayout.Direction for horizontal/vertical orientation

Blazor InlineEditMode

Blazor-specific inline editing (distinct from WinForms AllowEdit):

Detail View Layout & Dashboard Views

Refer to references/layout-and-dashboards.md

When you need to:

• Organize Detail View properties into groups and tabs with DetailViewLayoutAttribute
• Prevent layout auto-regeneration with FreezeLayout
• Create a DashboardView via ModelNodesGeneratorUpdater<ModelViewsNodesGenerator>
• Add navigation items for Dashboard Views

Accessing View Items and UI Controls

Refer to references/view-items-controls.md

Important: FindItem, GetItems, and direct control access must be called in or after OnViewControlsCreated, not in OnActivated. Controls do not exist during OnActivated. The CustomizeViewItemControl<T> extension method (from DetailViewExtensions) defers internally, so it can be called in OnActivated.

When you need to:

• Get a specific property editor by name via View.FindItem("Name") as PropertyEditor (null-check the result) and subscribe to ValueChanged
• Get all editors of a type via View.GetItems<PropertyEditor>()
• Customize Blazor component models via View.CustomizeViewItemControl<T>(this, editor => { ... }) — lambda receives the typed view item; access editor.ComponentModel (Blazor) or editor.Control (WinForms)
• Access the underlying grid control in OnViewControlsCreated (Blazor DxGridListEditor, WinForms GridListEditor)
• Access nested ListView editors via ListPropertyEditor.ListView

Non-Persistent Object Views

Show non-persistent objects (decorated with [DomainComponent]) in Views. Application.CreateObjectSpace(typeof(T)) returns a NonPersistentObjectSpace automatically for non-persistent types.

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// Show a non-persistent object's Detail View in a popup
IObjectSpace os = Application.CreateObjectSpace(typeof(ReportParameters));
var parameters = os.CreateObject<ReportParameters>();
DetailView view = Application.CreateDetailView(os, parameters);
var svp = new ShowViewParameters(view);
svp.TargetWindow = TargetWindow.NewModalWindow;
svp.Context = TemplateContext.PopupWindow;
Application.ShowViewStrategy.ShowView(svp, new ShowViewSource(Frame, null));

For navigation-based non-persistent List Views, subscribe to ((NonPersistentObjectSpace)objectSpace).ObjectsGetting to populate e.Objects with data (e.g., from a REST API). Handle CommitChanges if write-back is needed.

Troubleshooting

Constraints & Rules

1. Code-only configuration: All view configuration via C# code (attributes, controllers, Application Model API). No XAFML files or visual designers.
2. Use OnViewControlsCreated to access underlying UI controls, not OnActivated.
3. Always create ObjectSpace before creating a View.
4. Version consistency: All DevExpress packages must use the same version.

Using DevExpress Documentation MCP

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• Search: devexpress_docs_search(technologies=["eXpressAppFramework"], question="")

• Fetch: devexpress_docs_get_content(url="")

• Views: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/112611/ui-construction/views?md=true")

• Ways to show a view: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/112803/ui-construction/views/ways-to-show-a-view?md=true")

• Data access modes: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/113683/ui-construction/views/list-view-data-access-modes?md=true")

• Layout customization: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/112817/ui-construction/views/layout/view-items-layout-customization?md=true")

• Access UI elements: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/120092/ui-construction/ways-to-access-ui-elements-and-their-controls?md=true")

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