Events

AvalonDock uses an event-driven model to notify your application of docking operations. Many events follow a cancellable Closing/Closed pattern.

DockingManager Events

Document Lifecycle

Event	EventArgs	Cancellable	Description
`DocumentClosing`	`DocumentClosingEventArgs`	✅	Raised before a document is closed. Set `Cancel = true` to prevent.
`DocumentClosed`	`DocumentClosedEventArgs`	—	Raised after a document has been closed.

dockManager.DocumentClosing += (sender, args) =>
{
    // Prompt to save changes
    if (HasUnsavedChanges(args.Document))
    {
        var result = MessageBox.Show("Save changes?", "Confirm",
            MessageBoxButton.YesNoCancel);

        if (result == MessageBoxResult.Cancel)
            args.Cancel = true;
        else if (result == MessageBoxResult.Yes)
            Save(args.Document);
    }
};

Anchorable Lifecycle

Event	EventArgs	Cancellable	Description
`AnchorableClosing`	`AnchorableClosingEventArgs`	✅	Before an anchorable closes.
`AnchorableClosed`	`AnchorableClosedEventArgs`	—	After an anchorable is closed.
`AnchorableHiding`	`AnchorableHidingEventArgs`	✅	Before an anchorable hides.
`AnchorableHidden`	`AnchorableHiddenEventArgs`	—	After an anchorable is hidden.

dockManager.AnchorableHiding += (sender, args) =>
{
    // Prevent hiding of critical panels
    if (args.Anchorable.ContentId == "errorList")
    {
        args.Cancel = true;
        MessageBox.Show("The Error List cannot be hidden.");
    }
};

Docking Operations

Event	EventArgs	Description
`ContentDocked`	`ContentDockedEventArgs`	Content has been docked from a floating state.
`ContentFloating`	`ContentFloatingEventArgs`	Content has been floated from a docked state.
`LayoutFloatingWindowControlClosed`	`LayoutFloatingWindowControlClosedEventArgs`	A floating window control was closed.

Layout Changes

Event	EventArgs	Description
`ActiveContentChanged`	`EventArgs`	The active content has changed.
`LayoutChanged`	`EventArgs`	The layout structure has been modified.
`LayoutChanging`	`EventArgs`	The layout structure is about to be modified.

dockManager.ActiveContentChanged += (sender, args) =>
{
    var active = dockManager.ActiveContent;
    StatusBar.Text = $"Active: {active?.GetType().Name ?? "None"}";
};

LayoutContent Events

These events are available on individual LayoutDocument and LayoutAnchorable instances:

Event	Description
`Closing`	Before this content closes. Cancellable.
`Closed`	After this content is closed.
`IsActiveChanged`	When the `IsActive` property changes.
`IsSelectedChanged`	When the `IsSelected` property changes.

EventArgs Reference

DocumentClosingEventArgs

Property	Type	Description
`Document`	`LayoutDocument`	The document being closed.
`Cancel`	`bool`	Set to `true` to prevent closing.

AnchorableClosingEventArgs

Property	Type	Description
`Anchorable`	`LayoutAnchorable`	The anchorable being closed.
`Cancel`	`bool`	Set to `true` to prevent closing.

AnchorableHidingEventArgs

Property	Type	Description
`Anchorable`	`LayoutAnchorable`	The anchorable being hidden.
`Cancel`	`bool`	Set to `true` to prevent hiding.

ContentDockedEventArgs

Property	Type	Description
`Content`	`LayoutContent`	The content that was docked.

ContentFloatingEventArgs

Property	Type	Description
`Content`	`LayoutContent`	The content that started floating.

Common Patterns

Save-on-Close

dockManager.DocumentClosing += async (sender, args) =>
{
    if (args.Document.Content is IDocument doc && doc.IsDirty)
    {
        args.Cancel = true; // Prevent immediate close

        var result = await ShowSaveDialogAsync(doc);
        if (result != SaveResult.Cancel)
        {
            if (result == SaveResult.Save)
                await doc.SaveAsync();

            args.Document.Close(); // Close after handling
        }
    }
};

Track Active Document

dockManager.ActiveContentChanged += (sender, args) =>
{
    if (dockManager.ActiveContent is MyDocumentViewModel doc)
    {
        Title = $"MyApp - {doc.FileName}";
    }
};