XAF: WinForms UI Platform

Application Setup

// Program.cs
[STAThread]
static void Main() {
    Application.EnableVisualStyles();
    Application.SetCompatibleTextRenderingDefault(false);

    var winApplication = new MyWinApplication();
    winApplication.Setup();
    winApplication.Start();
}

// WinApplication.cs
public class MyWinApplication : WinApplication {
    public MyWinApplication() {
        DatabaseUpdateMode = DatabaseUpdateMode.UpdateDatabaseAlways;
        CheckCompatibilityType = CheckCompatibilityType.DatabaseSchema;
    }

    protected override void OnSetupStarted() {
        base.OnSetupStarted();
        ConnectionString = ConfigurationManager.ConnectionStrings["Default"].ConnectionString;
    }
}

Ribbon vs Standard Toolbar

Switch to Ribbon

// In WinApplication.cs constructor
UseOldTemplates = false; // uses Ribbon template by default

// Or explicitly set in Model Editor:
// Application > Options > FormStyle = Ribbon

Customize Ribbon Categories

// Via Application Model:
// ActionDesign > ActionToContainerMapping > ActionCategory → ContainerName
// NavigationItems > ... > Caption

Custom Ribbon Button from Controller

public class CustomRibbonController : WindowController {
    private SimpleAction customAction;

    public CustomRibbonController() {
        customAction = new SimpleAction(this, "CustomAction", "CustomCategory") {
            Caption = "Custom",
            ImageName = "Action_New",
            PaintStyle = ActionItemPaintStyle.CaptionAndImage
        };
        customAction.Execute += CustomAction_Execute;
    }
}

WinForms-Specific Editors

Accessing DevExpress WinForms Controls

using DevExpress.ExpressApp.Win.Editors;
using DevExpress.XtraGrid.Views.Grid;
using DevExpress.XtraEditors;

public class CustomizeWinFormsController : ObjectViewController<ListView, MyObject> {
    protected override void OnViewControlsCreated() {
        base.OnViewControlsCreated();

        // Access GridListEditor's underlying XtraGrid
        if (View.Editor is GridListEditor gridEditor) {
            GridView gridView = gridEditor.GridView;
            gridView.OptionsView.ShowGroupPanel = false;
            gridView.OptionsView.ShowFooter = true;

            // Configure column summaries
            foreach (GridColumn col in gridView.Columns) {
                if (col.FieldName == "Amount") {
                    col.Summary.Add(SummaryItemType.Sum, "Amount", "{0:C2}");
                }
            }
        }
    }
}

// Access DetailView editor control
public class DetailViewController : ObjectViewController<DetailView, MyObject> {
    protected override void OnViewControlsCreated() {
        base.OnViewControlsCreated();

        var nameEditor = View.FindItem("Name") as StringPropertyEditor;
        if (nameEditor?.Control is TextEdit textEdit) {
            textEdit.Properties.CharacterCasing = CharacterCasing.Upper;
        }
    }
}

Layout Customization

Via Model Editor (preferred)

Path: Views > <ClassName>_DetailView > Layout

Drag-and-drop property editors into groups, tabs, and columns.

Programmatic Layout (from Controller)

using DevExpress.ExpressApp.Win.Layout;
using DevExpress.XtraLayout;

public class LayoutController : ObjectViewController<DetailView, MyObject> {
    protected override void OnViewControlsCreated() {
        base.OnViewControlsCreated();

        // Access LayoutControl
        if (View.Control is DevExpress.ExpressApp.Win.Layout.XafLayoutControl layoutControl) {
            var root = layoutControl.Root;
            // Modify layout items, groups, visibility
        }
    }
}

Background Workers (Thread Safety)

public class LongOperationController : ViewController {
    private SimpleAction longAction;

    public LongOperationController() {
        longAction = new SimpleAction(this, "LongOp", PredefinedCategory.View) {
            Caption = "Run Long Operation"
        };
        longAction.Execute += LongAction_Execute;
    }

    private void LongAction_Execute(object sender, SimpleActionExecuteEventArgs e) {
        var worker = new BackgroundWorker { WorkerReportsProgress = true };

        // Run on background thread
        worker.DoWork += (s, args) => {
            // Long-running work — NO access to UI or XAF objects here
            Thread.Sleep(3000);
            args.Result = "Done";
        };

        // Update UI on UI thread after completion
        worker.RunWorkerCompleted += (s, args) => {
            if (args.Error != null)
                throw new UserFriendlyException(args.Error.Message);

            View.ObjectSpace.Refresh();
            Application.ShowViewStrategy.ShowMessage(args.Result.ToString());
        };

        worker.RunWorkerAsync();
    }
}

IMPORTANT: Never access IObjectSpace, View, Frame, or XAF objects from the DoWork handler — they are not thread-safe.

Splash Screen

// Custom splash screen class
public class MySplashScreen : ISplashScreen {
    private SplashScreenForm form;

    public void Start() {
        form = new SplashScreenForm();
        form.Show();
    }

    public void Stop() {
        form?.Invoke(() => form.Close());
        form = null;
    }

    public void SetDisplayText(string displayText) {
        form?.Invoke(() => form.UpdateStatus(displayText));
    }
}

// Register in WinApplication.cs
protected override void CreateDefaultObjectSpaceProvider(CreateCustomObjectSpaceProviderEventArgs args) {
    base.CreateDefaultObjectSpaceProvider(args);
    SplashScreen = new MySplashScreen();
}

WinForms Navigation

// Default: NavigationFrame with accordion/tree navigation
// To change navigation style in Application Model:
// Application > Options > NavigationStyle = Tree | Accordion | NavBar

// Programmatic navigation from controller:
var detailView = Application.CreateDetailView(objectSpace, targetObject);
Application.ShowViewStrategy.ShowView(
    new ShowViewParameters(detailView), new ShowViewSource(Frame, null));

Printing / Print Preview

using DevExpress.ExpressApp.ReportsV2;

// Built-in print via XtraReports:
var reportController = Frame.GetController<ReportServiceController>();
reportController.ShowPreviewAction.DoExecute(reportData);

// Direct XtraGrid printing:
if (View.Editor is GridListEditor editor) {
    editor.GridView.ShowPrintPreview();
}

Source Links

• WinForms Getting Started: https://docs.devexpress.com/eXpressAppFramework/402684/getting-started/in-depth-tutorial-winforms-webforms
• WinForms UI Customization: https://docs.devexpress.com/eXpressAppFramework/113072/ui-construction/windows-forms-ui-customization
• WinApplication API: https://docs.devexpress.com/eXpressAppFramework/DevExpress.ExpressApp.Win.WinApplication
• GridListEditor API: https://docs.devexpress.com/eXpressAppFramework/DevExpress.ExpressApp.Win.Editors.GridListEditor