WPF Behavior Generator

WPF Behavior Generator

If $0 is empty, use the AskUserQuestion tool to ask: "Enter the Behavior name (e.g., SelectAllOnFocus, DragMove)". Do NOT proceed until a valid name is provided. Use the response as the BehaviorName for all subsequent steps.

Generate a $0Behavior class based on Microsoft.Xaml.Behaviors.Wpf.

• Replace {TargetType} with the appropriate WPF type (e.g., TextBox, UIElement, Window) based on the behavior name and context.
• Replace {Namespace} with the project's root namespace detected from csproj or existing code.
• Replace {Project} with the target project path.

Generated Code

namespace {Namespace}.Behaviors;

public sealed class $0Behavior : Behavior<{TargetType}>
{
    #region Dependency Properties

    public static readonly DependencyProperty IsEnabledProperty =
        DependencyProperty.Register(
            nameof(IsEnabled),
            typeof(bool),
            typeof($0Behavior),
            new PropertyMetadata(true));

    public bool IsEnabled
    {
        get => (bool)GetValue(IsEnabledProperty);
        set => SetValue(IsEnabledProperty, value);
    }

    #endregion

    #region Lifecycle

    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.Loaded += OnLoaded;
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();
        AssociatedObject.Loaded -= OnLoaded;
    }

    #endregion

    #region Event Handlers

    private void OnLoaded(object sender, RoutedEventArgs e)
    {
        if (!IsEnabled)
        {
            return;
        }

        // TODO: Implement behavior logic
    }

    #endregion
}

XAML Usage

<Window xmlns:b="http://schemas.microsoft.com/xaml/behaviors"
        xmlns:behaviors="clr-namespace:{Namespace}.Behaviors">

    <{TargetType}>
        <b:Interaction.Behaviors>
            <behaviors:$0Behavior IsEnabled="{Binding IsBehaviorEnabled}"/>
        </b:Interaction.Behaviors>
    </{TargetType}>

</Window>

Common Behavior Patterns

Focus Management

public sealed class FocusOnLoadBehavior : Behavior<UIElement>
{
    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.Loaded += (s, e) => AssociatedObject.Focus();
    }
}

Input Handling

public sealed class EnterKeyBehavior : Behavior<TextBox>
{
    public static readonly DependencyProperty CommandProperty =
        DependencyProperty.Register(nameof(Command), typeof(ICommand),
            typeof(EnterKeyBehavior));

    public ICommand? Command
    {
        get => (ICommand?)GetValue(CommandProperty);
        set => SetValue(CommandProperty, value);
    }

    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.KeyDown += OnKeyDown;
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();
        AssociatedObject.KeyDown -= OnKeyDown;
    }

    private void OnKeyDown(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Enter)
        {
            Command?.Execute(AssociatedObject.Text);
        }
    }
}

Required Package

<PackageReference Include="Microsoft.Xaml.Behaviors.Wpf" Version="1.1.*" />

File Location

{Project}/
└── Behaviors/
    └── $0Behavior.cs

Best Practices

DO	DON'T
Unsubscribe events in OnDetaching	Missing event unsubscription (memory leak)
Expose settings via DependencyProperty	Use hardcoded values
Apply IsEnabled pattern	Always execute without condition
Check AssociatedObject for null	Use without null check