DevExpress XAF — Editors (Property Editors, List Editors & View Items)

Editors are the building blocks that render individual properties (Property Editors), entire object collections (List Editors), and custom UI elements (View Items) inside XAF Views.

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Prerequisites & Installation

Editors are part of the core XAF framework — no additional module registration is required. Platform-specific editor code belongs in the corresponding platform project.

NuGet Packages

Package	Purpose	Project
DevExpress.ExpressApp	PropertyEditor base class, ViewItem, ListEditor abstractions	MySolution.Module
DevExpress.ExpressApp.Blazor	BlazorPropertyEditorBase, Blazor editor models	MySolution.Blazor.Server
DevExpress.ExpressApp.Blazor.Editors	BlazorControlViewItem, DxGridListEditor, DxTreeListEditor	MySolution.Blazor.Server
DevExpress.ExpressApp.Win	WinForms DXPropertyEditor, GridListEditor, TreeListEditor	MySolution.Win

All packages are included in XAF projects created from the template.

Where to Place Custom Editors

Type	Platform-agnostic	Blazor	WinForms
Custom Property Editor	—	MySolution.Blazor.Server\Editors\	MySolution.Win\Editors\
Custom List Editor	—	MySolution.Blazor.Server\Editors\	MySolution.Win\Editors\
Custom View Item	MySolution.Module\ViewItems\	MySolution.Blazor.Server\Editors\	MySolution.Win\Editors\
Controller customizing editors	MySolution.Module\Controllers\	MySolution.Blazor.Server\Controllers\	MySolution.Win\Controllers\

Custom editors are discovered automatically via [PropertyEditor], [ListEditor], or [ViewItem] attributes — no manual registration in Module.cs is needed.

Key Using Statements

using DevExpress.ExpressApp.Editors;       // PropertyEditor, ListEditor, ViewItem, ColumnWrapper
using DevExpress.ExpressApp.Model;         // IModelColumn, IModelMember, IModelListView
// Blazor:
using DevExpress.ExpressApp.Blazor.Editors;         // BlazorPropertyEditorBase, DxGridListEditor
using DevExpress.ExpressApp.Blazor.Editors.Models;  // DxGridModel, DxDateEditModel, etc.
// WinForms:
using DevExpress.ExpressApp.Win.Editors;   // DXPropertyEditor, GridListEditor

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Property Editor Class Hierarchy

PropertyEditor (abstract, platform-independent)
├── BlazorPropertyEditorBase          — Blazor editors
│   ├── StringPropertyEditor
│   ├── NumericPropertyEditor
│   ├── DateTimePropertyEditor
│   ├── LookupPropertyEditor
│   ├── BooleanPropertyEditor
│   ├── EnumPropertyEditor
│   └── (other built-in Blazor editors)
├── WinPropertyEditor                 — WinForms editors (custom control)
│   └── DXPropertyEditor             — WinForms editors using XtraEditors
│       ├── DatePropertyEditor
│       ├── StringPropertyEditor
│       ├── IntegerPropertyEditor
│       └── (other built-in Win editors)

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Built-in Property Editors — Data Type Mapping

Property Type	Blazor Editor	WinForms Editor
string	StringPropertyEditor (DxTextBox)	StringPropertyEditor (TextEdit)
int, decimal, double	NumericPropertyEditor (DxSpinEdit)	IntegerPropertyEditor / DecimalPropertyEditor
DateTime	DateTimePropertyEditor (DxDateEdit)	DatePropertyEditor (DateEdit)
bool	BooleanPropertyEditor (DxCheckBox or DxComboBox)	BooleanPropertyEditor (CheckEdit)
enum	EnumPropertyEditor (DxComboBox)	EnumPropertyEditor (ImageComboBoxEdit)
Reference (FK)	LookupPropertyEditor (DxComboBox with lookup)	LookupPropertyEditor (LookupEdit)
byte[] image	ImagePropertyEditor	ImagePropertyEditor
File attachment	DxFileDataPropertyEditor	FileDataPropertyEditor
Collection	ListPropertyEditor (nested ListView)	ListPropertyEditor (nested ListView)
CriteriaOperator	CriteriaPropertyEditor	PopupCriteriaPropertyEditor
Color	ColorPropertyEditor	ColorPropertyEditor
Type	TypePropertyEditor	TypePropertyEditor

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Customizing Built-in Property Editors

Refer to references/customize-editors.md

When you need to:

• Use CustomizeViewItemControl in a controller to configure Blazor or WinForms editors without subclassing
• Target a specific property by name for customization
• Make a property read-only (AllowEdit) or hidden (ViewItemVisibility)
• Add custom buttons to Blazor editors via DxEditorButtonModel
• Hide New/Edit buttons on Lookup Property Editors
• Implement IComplexViewItem to access ObjectSpace and XafApplication in a custom editor

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Implementing Custom Property Editors

Refer to references/custom-property-editors.md

When you need to:

• Build a Blazor Property Editor from scratch using the ComponentModel pattern
• Wrap an existing DevExpress Blazor component as a simplified Property Editor
• Control how a custom editor renders in List View grid cells (CreateViewComponentCore)
• Build a WinForms Property Editor with CreateControlCore and IInplaceEditSupport
• Inherit from a built-in WinForms editor (DXPropertyEditor) and customize via SetupRepositoryItem
• Register editors with PropertyEditorAttribute and understand default vs non-default assignment

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Custom Buttons & Lookup Configuration

Refer to references/customize-editors.md

When you need to:

• Add icon buttons to Blazor property editors via DxEditorButtonModel
• Hide or restore New/Edit buttons on LookupPropertyEditor
• Implement IComplexViewItem so a custom editor can access ObjectSpace and XafApplication

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List Editors

Built-in List Editors

Platform	Editor	Control	Use Case
Blazor	DxGridListEditor	DxGrid	Default grid
Blazor	DxTreeListEditor	DxTreeList	Hierarchical data
Blazor	DxChartListEditor	DxChart	Chart visualization
Blazor	SchedulerListEditor	DxScheduler	Scheduling
WinForms	GridListEditor	XtraGrid GridControl	Default grid
WinForms	TreeListEditor	TreeList	Hierarchical data
WinForms	ChartListEditor	ChartControl	Chart visualization
WinForms	SchedulerListEditor	SchedulerControl	Scheduling
WinForms	PivotGridListEditor	PivotGridControl	Pivot tables

Accessing & Customizing List Editors

Refer to references/list-editors.md

When you need to:

• Access DxGridListEditor or GridListEditor controls in OnViewControlsCreated
• Customize columns, group panel, resize mode, or filter buttons on the grid
• Use platform-agnostic ColumnsListEditor API that works on both Blazor and WinForms
• Access the DxGrid component instance directly for runtime method calls
• Implement a custom List Editor with IComponentContentHolder (Blazor)

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Custom View Items

Refer to references/custom-view-items.md

When you need to:

• Create a custom ViewItem (e.g., a button) using ViewItemAttribute and IComponentContentHolder
• Embed a Razor component in a Dashboard View using BlazorControlViewItem with CascadingParameter
• Access ObjectSpace from a Razor component embedded in a View

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Troubleshooting

Symptom	Cause	Solution
Custom editor not in Model Editor	Missing PropertyEditorAttribute	Add [PropertyEditor(typeof(T), false)]
Editor shows but value doesn't bind	ReadValueCore/GetControlValueCore not overridden	Override both methods
Grid column not editable	IInplaceEditSupport not implemented (WinForms)	Implement CreateRepositoryItem()
Null reference in CustomizeViewItemControl	Called in wrong lifecycle	Use OnActivated, not constructor
List Editor doesn't display	ListEditorAttribute missing or wrong type	Add [ListEditor(typeof(IMyType))]
Blazor ComponentModel not rendering	Missing IComponentContentHolder	Implement the interface on your editor/ViewItem
WinForms custom control not visible	CreateControlCore returns null	Ensure control is instantiated and returned

Constraints & Rules

1. No XAFML/Model Editor file editing: Register editors via PropertyEditorAttribute / ListEditorAttribute in code; assign via Application Model API in controllers.
2. Platform-specific code: Blazor editors in .Blazor.Server project, WinForms editors in .Win project.
3. Use OnViewControlsCreated (not OnActivated) to access underlying UI controls of List Editors.
4. Use CustomizeViewItemControl in OnActivated to configure Property Editors — it handles the correct lifecycle automatically.
5. 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="")

• Property Editors: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/113097/ui-construction/view-items-and-property-editors/property-editors?md=true")

• Data types & editors: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/113014/business-model-design-orm/data-types-supported-by-built-in-editors?md=true")

• List Editors: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/113189/ui-construction/list-editors?md=true")

• Custom Blazor Property Editor: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/402189/ui-construction/view-items-and-property-editors/property-editors/implement-a-property-editor-based-on-custom-components-blazor?md=true")

• Custom Blazor List Editor: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/403258/ui-construction/list-editors/how-to-use-a-custom-component-to-implement-list-editor-blazor?md=true")

• Access grid control: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/402154/ui-construction/list-editors/how-to-access-list-editor-control?md=true")

• Custom ViewItem (button): devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/113653/ui-construction/view-items-and-property-editors/add-a-button-to-a-detail-view-using-custom-view-item?md=true")

• Custom buttons in editors: devexpress_docs_get_content(url="https://docs.devexpress.com/content/eXpressAppFramework/405839/ui-construction/view-items-and-property-editors/property-editors/add-a-custom-button-to-a-property-editor?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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