XAML Behaviors

Xaml Behaviors is a port of Windows UWP version of XAML Behaviors for Avalonia XAML.

Avalonia XAML Behaviors is an easy-to-use means of adding common and reusable interactivity to your Avalonia applications with minimal code. Avalonia port is available only for managed applications. Use of XAML Behaviors is governed by the MIT License.

Building Avalonia XAML Behaviors

First, clone the repository or download the latest zip.

git clone https://github.com/wieslawsoltes/Xaml.Behaviors.git

Build on Windows using script

• .NET Core.

Open up a command-prompt and execute the commands:

.\build.ps1

Build on Linux using script

• .NET Core.

Open up a terminal prompt and execute the commands:

./build.sh

Build on OSX using script

• .NET Core.

Open up a terminal prompt and execute the commands:

./build.sh

NuGet

Avalonia XamlBehaviors is delivered as a NuGet package.

You can find the packages here NuGet and install the package like this:

Install-Package Xaml.Behaviors

or by using nightly build feed:

• Add https://www.myget.org/F/xamlbehaviors-nightly/api/v2 to your package sources
• Alternative nightly build feed https://pkgs.dev.azure.com/wieslawsoltes/GitHub/_packaging/Nightly/nuget/v3/index.json
• Update your package using XamlBehaviors feed

and install the package like this:

Install-Package Xaml.Behaviors -Pre

Package Sources

• https://api.nuget.org/v3/index.json

Docs

This section provides an overview of all available classes and their purpose in Avalonia XAML Behaviors. The classes are grouped into logical categories based on their functionality.

Interactions

Actions

• AddClassAction
  Adds a style class to a control’s class collection, making it easy to change the appearance dynamically.

• ChangeAvaloniaPropertyAction
  Changes the value of an Avalonia property on a target object at runtime.

• CloseNotificationAction
  Closes an open notification, for example, from a notification control.

• FocusControlAction
  Sets the keyboard focus on a specified control or the associated control.

• PopupAction
  Displays a popup window for showing additional UI content.

• RemoveClassAction
  Removes a style class from a control’s class collection.

Animations

• FadeInBehavior
  Animates the fade-in effect for the associated element, gradually increasing its opacity.

• StartAnimationAction
  Triggers a defined animation on the target control when executed.

AutoCompleteBox

• FocusAutoCompleteBoxTextBoxBehavior
  Ensures the text box within an AutoCompleteBox gets focus automatically.

Button

• ButtonClickEventTriggerBehavior
  Listens for a button’s click event and triggers associated actions.

• ButtonExecuteCommandOnKeyDownBehavior
  Executes a command when a specified key is pressed while the button is focused.

• ButtonHideFlyoutBehavior
  Hides an attached flyout when the button is interacted with.

• ButtonHideFlyoutOnClickBehavior
  Automatically hides the flyout attached to the button when it is clicked.

Clipboard

• ClearClipboardAction
  Clears all contents from the system clipboard.

• GetClipboardDataAction
  Retrieves data from the clipboard in a specified format.

• GetClipboardFormatsAction
  Retrieves the list of available formats from the clipboard.

• GetClipboardTextAction
  Retrieves plain text from the clipboard.

• SetClipboardDataObjectAction
  Places a custom data object onto the clipboard.

• SetClipboardTextAction
  Places text onto the clipboard.

Composition

• SelectingItemsControlBehavior
  Animates selection transitions in items controls such as ListBox or TabControl.

• SlidingAnimation
  Provides static methods to apply sliding animations (from left, right, top, or bottom) to a control.

Control

• BindPointerOverBehavior
  Two‑way binds a boolean property to a control’s pointer-over state.

• BindTagToVisualRootDataContextBehavior
  Binds the control’s Tag property to the DataContext of its visual root, enabling inherited data contexts.

• BoundsObserverBehavior
  Observes a control’s bounds changes and updates two‑way bound Width and Height properties.

• DragControlBehavior
  Enables a control to be moved (dragged) around by changing its RenderTransform during pointer events.

• HideAttachedFlyoutBehavior
  Hides a flyout that is attached to a control when a condition is met.

• HideOnKeyPressedBehavior
  Hides the target control when a specified key is pressed.

• HideOnLostFocusBehavior
  Hides the target control when it loses focus.

• ShowPointerPositionBehavior
  Displays the current pointer position (x, y coordinates) in a TextBlock for debugging or UI feedback.

Converters

• PointerEventArgsConverter
  Converts pointer event arguments into a tuple (x, y) representing the pointer’s location.

Core (General Infrastructure)

• ActualThemeVariantChangedBehavior
  A base class for behaviors that react to theme variant changes (e.g. switching from light to dark mode).

• ActualThemeVariantChangedTrigger
  Triggers actions when the actual theme variant of a control changes.

• AttachedToLogicalTreeBehavior
  A base class for behaviors that require notification when the associated object is added to the logical tree.

• AttachedToLogicalTreeTrigger
  Triggers actions when an element is attached to the logical tree.

• AttachedToVisualTreeBehavior
  A base class for behaviors that depend on the control being attached to the visual tree.

• AttachedToVisualTreeTrigger
  Triggers actions when the associated element is added to the visual tree.

• BindingBehavior
  Establishes a binding on a target property using an Avalonia binding.

• BindingTriggerBehavior
  Monitors a binding’s value and triggers actions when a specified condition is met.

• CallMethodAction
  Invokes a method on a target object when the action is executed.

• ChangePropertyAction
  Changes a property on a target object to a new value using type conversion if needed.

• DataContextChangedBehavior
  A base class for behaviors that react to changes in the DataContext.

• DataContextChangedTrigger
  Triggers actions when the DataContext of a control changes.

• DataTriggerBehavior
  Evaluates a data binding against a given condition and triggers actions when the condition is true.

• DetachedFromLogicalTreeTrigger
  Triggers actions when the control is removed from the logical tree.

• DetachedFromVisualTreeTrigger
  Triggers actions when the control is removed from the visual tree.

• DisposingBehavior
  A base class for behaviors that manage disposable resources automatically.

• DisposingTrigger
  A base class for triggers that need to dispose of resources when detached.

• EventTriggerBehavior
  Listens for a specified event on the associated object and triggers actions accordingly.

• InitializedBehavior
  A base class for behaviors that execute code when the associated object is initialized.

• InitializedTrigger
  Triggers actions once the control is initialized.

• InvokeCommandAction
  Executes a bound ICommand when the action is invoked.

• InvokeCommandActionBase
  The base class for actions that invoke commands, with support for parameter conversion.

• LoadedBehavior
  A base class for behaviors that run when a control is loaded into the visual tree.

• LoadedTrigger
  Triggers actions when the control’s Loaded event fires.

• ResourcesChangedBehavior
  A base class for behaviors that respond when a control’s resources change.

• ResourcesChangedTrigger
  Triggers actions when the control’s resources are modified.

• RoutedEventTriggerBase
  A base class for triggers that listen for a routed event and execute actions.

• RoutedEventTriggerBaseOfT
  A generic version of RoutedEventTriggerBase for strongly typed routed event args.

• RoutedEventTriggerBehavior
  Listens for a routed event on the associated object and triggers its actions.

• UnloadedTrigger
  Triggers actions when the control is unloaded from the visual tree.

• ValueChangedTriggerBehavior
  Triggers actions when the value of a bound property changes.

DragAndDrop

• ContextDragBehavior
  Enables drag operations using a “context” (data payload) that is carried during the drag–drop operation.

• ContextDropBehavior
  Handles drop events and passes context data between the drag source and drop target.

• DropHandlerBase
  Provides common helper methods (move, swap, insert) for implementing custom drop logic.

• IDragHandler
  Interface for classes that handle additional logic before and after a drag–drop operation.

• IDropHandler
  Interface for classes that implement validation and handling of drop operations.

• TypedDragBehavior
  Provides drag behavior for items of a specified data type.

Draggable

• CanvasDragBehavior
  Enables a control to be dragged within a Canvas by updating its RenderTransform based on pointer movements.

• GridDragBehavior
  Allows grid cells (or items) to be swapped or repositioned by dragging within a Grid layout.

• ItemDragBehavior
  Enables reordering of items in an ItemsControl by dragging and dropping items.

• SelectionAdorner
  A visual adorner used to indicate selection or to show drag outlines during drag–drop operations.

Events

• InteractiveBehaviorBase
  Base class for behaviors that listen to UI events, providing common functionality for event triggers.

• DoubleTappedEventBehavior
  Listens for double-tap events and triggers its actions when detected.

• GotFocusEventBehavior
  Executes actions when the associated control receives focus.

• KeyDownEventBehavior
  Monitors key down events and triggers actions when the specified key is pressed.

• KeyUpEventBehavior
  Monitors key up events and triggers actions when the specified key is released.

• LostFocusEventBehavior
  Triggers actions when the control loses focus.

• PointerCaptureLostEventBehavior
  Listens for events when pointer capture is lost and triggers associated actions.

• PointerEnteredEventBehavior
  Triggers actions when the pointer enters the bounds of a control.

• PointerEventsBehavior
  A base class that simplifies handling of pointer events (pressed, moved, released).

• PointerExitedEventBehavior
  Triggers actions when the pointer exits a control.

• PointerMovedEventBehavior
  Triggers actions when the pointer moves over a control.

• PointerPressedEventBehavior
  Triggers actions on pointer press events.

• PointerReleasedEventBehavior
  Triggers actions on pointer release events.

• PointerWheelChangedEventBehavior
  Triggers actions when the pointer wheel (scroll) changes.

• RightTappedEventBehavior
  Triggers actions when the control is right-tapped.

• ScrollGestureEndedEventBehavior
  Triggers actions when a scroll gesture ends.

• ScrollGestureEventBehavior
  Monitors scroll gestures and triggers actions when they occur.

• TappedEventBehavior
  Triggers actions on simple tap events.

• TextInputEventBehavior
  Listens for text input events and triggers actions accordingly.

• TextInputMethodClientRequestedEventBehavior
  Triggers actions when a text input method client is requested (for virtual keyboards, etc.).

ExecuteCommand Core

• ExecuteCommandBehaviorBase
  Provides the core functionality for executing a command from within a behavior.

• ExecuteCommandOnKeyBehaviorBase
  A base class for command behaviors triggered by key events.

• ExecuteCommandRoutedEventBehaviorBase
  A base class for command behaviors that respond to routed events.

ExecuteCommand

• ExecuteCommandOnActivatedBehavior
  Executes a command when the main window (or target window) is activated.

• ExecuteCommandOnDoubleTappedBehavior
  Executes a command when the associated control is double-tapped.

• ExecuteCommandOnGotFocusBehavior
  Executes a command when the control gains focus.

• ExecuteCommandOnHoldingBehavior
  Executes a command when a holding (long press) gesture is detected.

• ExecuteCommandOnKeyDownBehavior
  Executes a command in response to a key down event matching a specified key or gesture.

• ExecuteCommandOnKeyUpBehavior
  Executes a command in response to a key up event matching a specified key or gesture.

• ExecuteCommandOnLostFocusBehavior
  Executes a command when the control loses focus.

• ExecuteCommandOnPinchBehavior
  Executes a command when a pinch gesture is in progress.

• ExecuteCommandOnPinchEndedBehavior
  Executes a command when a pinch gesture ends.

• ExecuteCommandOnPointerCaptureLostBehavior
  Executes a command when pointer capture is lost from the control.

• ExecuteCommandOnPointerEnteredBehavior
  Executes a command when the pointer enters the control’s area.

• ExecuteCommandOnPointerExitedBehavior
  Executes a command when the pointer exits the control’s area.

• ExecuteCommandOnPointerMovedBehavior
  Executes a command when the pointer moves over the control.

• ExecuteCommandOnPointerPressedBehavior
  Executes a command when the pointer is pressed on the control.

• ExecuteCommandOnPointerReleasedBehavior
  Executes a command when the pointer is released over the control.

• ExecuteCommandOnPointerTouchPadGestureMagnifyBehavior
  Executes a command during a touchpad magnify gesture.

• ExecuteCommandOnPointerTouchPadGestureRotateBehavior
  Executes a command during a touchpad rotation gesture.

• ExecuteCommandOnPointerTouchPadGestureSwipeBehavior
  Executes a command during a touchpad swipe gesture.

• ExecuteCommandOnPointerWheelChangedBehavior
  Executes a command when the pointer wheel delta changes.

• ExecuteCommandOnPullGestureBehavior
  Executes a command when a pull gesture is detected.

• ExecuteCommandOnPullGestureEndedBehavior
  Executes a command when a pull gesture ends.

• ExecuteCommandOnRightTappedBehavior
  Executes a command when the control is right-tapped.

• ExecuteCommandOnScrollGestureBehavior
  Executes a command during a scroll gesture.

• ExecuteCommandOnScrollGestureEndedBehavior
  Executes a command when a scroll gesture ends.

• ExecuteCommandOnScrollGestureInertiaStartingBehavior
  Executes a command when the inertia phase of a scroll gesture starts.

• ExecuteCommandOnTappedBehavior
  Executes a command when a tap event occurs.

• ExecuteCommandOnTextInputBehavior
  Executes a command in response to text input events.

• ExecuteCommandOnTextInputMethodClientRequestedBehavior
  Executes a command when text input method (virtual keyboard) is requested.

• InvokeCommandBehaviorBase
  The base class that supports converting parameters and invoking a bound command.

Focus

• FocusBehavior
  Exposes a two‑way bindable IsFocused property to control focus state.

• FocusBehaviorBase
  Provides a base implementation for focus behaviors, including support for navigation methods and key modifiers.

• FocusControlBehavior
  Forces focus onto a specified control when triggered.

• FocusOnAttachedBehavior
  Immediately focuses the control when the behavior is attached.

• FocusOnAttachedToVisualTreeBehavior
  Focuses the control as soon as it is attached to the visual tree.

• FocusOnPointerMovedBehavior
  Sets focus on the control when pointer movement is detected.

• FocusOnPointerPressedBehavior
  Focuses the control when a pointer press event occurs.

• FocusSelectedItemBehavior
  Focuses the currently selected item in an ItemsControl.

Gestures

• DoubleTappedGestureTrigger
  Triggers actions when a double-tap gesture is detected.

• HoldingGestureTrigger
  Triggers actions when a holding (long press) gesture is detected.

• PinchEndedGestureTrigger
  Triggers actions when a pinch gesture has ended.

• PinchGestureTrigger
  Triggers actions during a pinch gesture.

• PointerTouchPadGestureMagnifyGestureTrigger
  Triggers actions during a touchpad magnification gesture.

• PointerTouchPadGestureRotateGestureTrigger
  Triggers actions during a touchpad rotation gesture.

• PointerTouchPadGestureSwipeGestureTrigger
  Triggers actions during a touchpad swipe gesture.

• PullGestureEndedGestureTrigger
  Triggers actions when a pull gesture ends.

• PullGestureGestureTrigger
  Triggers actions during a pull gesture.

• RightTappedGestureTrigger
  Triggers actions on a right-tap gesture.

• ScrollGestureEndedGestureTrigger
  Triggers actions when a scroll gesture completes.

• ScrollGestureGestureTrigger
  Triggers actions during a scroll gesture.

• ScrollGestureInertiaStartingGestureTrigger
  Triggers actions when the inertia phase of a scroll gesture begins.

• TappedGestureTrigger
  Triggers actions on a simple tap gesture.

InputElement Actions

• CapturePointerAction
  Captures the pointer (mouse, touch) to a target control so that subsequent pointer events are routed there.

• ReleasePointerCaptureAction
  Releases a previously captured pointer from the control.

InputElement Triggers

• DoubleTappedTrigger
  Listens for a double-tap event and executes its actions.

• GotFocusTrigger
  Triggers actions when the control receives focus.

• HoldingTrigger
  Triggers actions when a holding gesture is detected.

• KeyDownTrigger
  Listens for key down events and triggers actions if the pressed key (or gesture) matches the specified criteria.

• KeyUpTrigger
  Listens for key up events and triggers actions when conditions are met.

• LostFocusTrigger
  Triggers actions when the control loses focus.

• PointerCaptureLostTrigger
  Triggers actions when pointer capture is lost by the control.

• PointerEnteredTrigger
  Triggers actions when the pointer enters the control’s area.

• PointerExitedTrigger
  Triggers actions when the pointer exits the control’s area.

• PointerMovedTrigger
  Triggers actions on pointer movement over the control.

• PointerPressedTrigger
  Triggers actions when the pointer is pressed on the control.

• PointerReleasedTrigger
  Triggers actions when the pointer is released on the control.

• PointerWheelChangedTrigger
  Triggers actions on mouse wheel (or equivalent) changes.

• TappedTrigger
  Triggers actions on a tap event.

• TextInputMethodClientRequestedTrigger
  Triggers actions when a text input method (virtual keyboard) is requested.

• TextInputTrigger
  Triggers actions on text input events.

ItemsControl

• ItemNudgeDropBehavior
  Provides “nudge” effects for items in an ItemsControl during drag–drop reordering.

• ItemsControlContainerClearingTrigger
  Triggers actions when the ItemsControl clears its container(s).

• ItemsControlContainerEventsBehavior
  A base behavior that listens for container events (prepared, index changed, clearing) on an ItemsControl.

• ItemsControlContainerIndexChangedTrigger
  Triggers actions when the index of an item’s container changes.

• ItemsControlContainerPreparedTrigger
  Triggers actions when a container for an item is prepared.

• ScrollToItemBehavior
  Automatically scrolls the ItemsControl to make a specified item visible.

• ScrollToItemIndexBehavior
  Scrolls to a specific item index in the ItemsControl.

ListBox

• ListBoxSelectAllBehavior
  Selects all items in a ListBox when the behavior is attached.

• ListBoxUnselectAllBehavior
  Clears the selection in a ListBox.

ListBoxItem

• SelectListBoxItemOnPointerMovedBehavior
  Automatically selects a ListBoxItem when the pointer moves over it.

Responsive

• AdaptiveBehavior
  Observes bounds changes of a control (or a specified source) and conditionally adds or removes CSS-style classes based on adaptive rules.

• AdaptiveClassSetter
  Specifies comparison conditions (min/max width/height) and the class to apply when those conditions are met.

ScrollViewer

• HorizontalScrollViewerBehavior
  Enables horizontal scrolling via the pointer wheel. Optionally requires the Shift key and supports line or page scrolling.

SelectingItemsControl

• SelectingItemsControlEventsBehavior
  Handles selection-changed events in controls that support item selection (like ListBox) to trigger custom actions.

Show

• ShowBehaviorBase
  A base class for behaviors that “show” (make visible) a target control when a trigger condition is met.

• ShowOnDoubleTappedBehavior
  Shows a control when a double-tap gesture is detected.

• ShowOnKeyDownBehavior
  Shows a control when a specified key (or key gesture) is pressed.

• ShowOnTappedBehavior
  Shows the target control when it is tapped.

StorageProvider – Button

• ButtonOpenFilePickerBehavior
  Attaches to a Button to open a file picker dialog when clicked.

• ButtonOpenFolderPickerBehavior
  Attaches to a Button to open a folder picker dialog when clicked.

• ButtonSaveFilePickerBehavior
  Attaches to a Button to open a save file picker dialog when clicked.

StorageProvider – Converters

• StorageFileToReadStreamConverter
  Converts an IStorageFile into a read stream (asynchronously).

• StorageFileToWriteStreamConverter
  Converts an IStorageFile into a write stream (asynchronously).

• StorageItemToPathConverter
  Extracts the file system path from an IStorageItem.

StorageProvider – Core

• PickerActionBase
  Base class for actions that invoke file/folder picker dialogs.

• PickerBehaviorBase
  Base class for behaviors that wrap file/folder picker functionality.

StorageProvider – MenuItem

• MenuItemOpenFilePickerBehavior
  Opens a file picker dialog when a MenuItem is clicked.

• MenuItemSaveFilePickerBehavior
  Opens a save file picker dialog when a MenuItem is clicked.

• MenuItemOpenFolderPickerBehavior
  Opens a folder picker dialog when a MenuItem is clicked.

StorageProvider – Utilities

• FileFilterParser
  Parses file filter strings (e.g. "Images|.png;.jpg") into file type objects for use with pickers.

StorageProvider

• OpenFilePickerAction
  Opens a file picker dialog and passes the selected file(s) as a command parameter.

• OpenFilePickerBehaviorBase
  Base behavior for opening file picker dialogs.

• OpenFolderPickerAction
  Opens a folder picker dialog and passes the selected folder(s) as a command parameter.

• OpenFolderPickerBehaviorBase
  Base behavior for opening folder picker dialogs.

• SaveFilePickerAction
  Opens a save file picker dialog and passes the chosen file as a command parameter.

• SaveFilePickerBehaviorBase
  Base behavior for saving files using a file picker dialog.

TextBox

• TextBoxSelectAllOnGotFocusBehavior
  Selects all text in a TextBox when it gains focus.

• TextBoxSelectAllTextBehavior
  Selects all text in a TextBox immediately upon attachment.

TreeViewItem

• ToggleIsExpandedOnDoubleTappedBehavior
  Toggles the IsExpanded property of a TreeViewItem when it is double-tapped.

Interactivity (Infrastructure)

AvaloniaObject

• Action
  The base class for actions that can be executed by triggers.

• Behavior
  The base class for behaviors that attach to Avalonia objects.

• BehaviorOfT
  Generic base class for behaviors that require a specific type of associated object.

• Trigger
  A base class for triggers that execute a collection of actions when activated.

• TriggerOfT
  A generic version of Trigger for strongly typed associated objects.

Collections

• ActionCollection
  A collection of actions that can be executed by a trigger.

• BehaviorCollection
  A collection of behaviors attached to a single Avalonia object.

Contract

• ComparisonConditionType
  Defines the types of comparisons (equal, not equal, less than, etc.) used in data and adaptive triggers.

• IAction
  Interface that defines the Execute method for custom actions.

• IBehavior
  Interface for behaviors that can attach and detach from an Avalonia object.

• IBehaviorEventsHandler
  Interface for handling events (loaded, attached, etc.) within behaviors.

• ITrigger
  Interface for triggers that encapsulate a collection of actions.

Helpers

• ComparisonConditionTypeHelper
  Helper class for performing comparisons based on a specified condition type.

• TemplatedParentHelper
  Helps to assign the templated parent for TemplateBinding support.

• TypeConverterHelper
  Assists in converting string values to a target type for property assignment.

StyledElement

• StyledElementAction
  A base class for actions that work with StyledElement objects.

• StyledElementBehavior
  A base class for behaviors targeting StyledElement objects.

• StyledElementBehaviorOfT
  Generic base class for behaviors that are attached to a specific type of StyledElement.

• StyledElementTrigger
  A base trigger class for StyledElement objects.

• StyledElementTriggerOfT
  Generic version of the StyledElementTrigger for typed associated objects.

Templates

• BehaviorCollectionTemplate
  Defines a XAML template for creating a collection of behaviors.

Interactivity

• Interaction
  A static helper class for managing behavior collections and executing actions associated with triggers.

Resources

• GitHub source code repository.

License

Avalonia XAML Behaviors is licensed under the MIT license.