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OutWit.Common.MVVM.WPF 2.0.4

OutWit.Common.MVVM.WPF

WPF-specific MVVM components and utilities, including source generator for automatic DependencyProperty generation.

Features

• Source Generator for DependencyProperty: Automatically generate DependencyProperty from attributes
• WPF Commands: Command and DelegateCommand with CommandManager integration
• Binding Utilities: Helper methods for DependencyProperty registration
• Visual Tree Traversal: Extension methods for navigating WPF visual tree
• BindingProxy: Freezable binding proxy for DataContext access
• Legacy Support: Obsolete BindableAttribute for backward compatibility

Installation

dotnet add package OutWit.Common.MVVM.WPF

This automatically includes:

• OutWit.Common.MVVM (base cross-platform package)
• OutWit.Common.MVVM.WPF.Generator (source generator)
• OutWit.Common.Logging

Quick Start

Source Generator for DependencyProperty

The simplest way to create DependencyProperties:

using System.Windows.Controls;
using OutWit.Common.MVVM.WPF.Attributes;

namespace MyApp.Controls
{
 public partial class CustomButton : Button
 {
 [StyledProperty(DefaultValue = "Click Me")]
 public string Label { get; set; }

 [StyledProperty(AffectsMeasure = true)]
 public double IconSize { get; set; }
 }
}

Important: Mark your class as partial to allow source generator to add code.

The generator automatically creates:

// Generated code (you don't write this):
public static readonly DependencyProperty LabelProperty = ...;
public static readonly DependencyProperty IconSizeProperty = ...;

Advanced Property Generation

public partial class AdvancedControl : Control
{
 // Full explicit configuration
 [StyledProperty(
 DefaultValue = 100.0,
 AffectsMeasure = true,
 AffectsArrange = true,
 BindsTwoWayByDefault = true,
 OnChanged = nameof(OnWidthChanged))]
 public double CustomWidth { get; set; }

 private static void OnWidthChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
 {
 var control = (AdvancedControl)d;
 // Handle change
 }
}

Convention-Based Callbacks

The generator automatically discovers callback methods by naming convention:

public partial class SmartControl : Control
{
 // No need to specify OnChanged - automatically discovered!
 [StyledProperty(DefaultValue = "Hello")]
 public string Title { get; set; }

 // Convention: On{PropertyName}Changed
 private static void OnTitleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
 {
 var control = (SmartControl)d;
 // Handle title change
 }

 // No need to specify Coerce - automatically discovered!
 [StyledProperty(DefaultValue = 100.0)]
 public double Width { get; set; }

 // Convention: {PropertyName}Coerce
 private static object WidthCoerce(DependencyObject d, object value)
 {
 return Math.Max(0, (double)value); // Ensure non-negative
 }
}

Benefits:

• ? Less boilerplate code
• ? Cleaner attributes
• ? Compile-time safety
• ? Override with explicit parameter when needed

Attached Properties

using OutWit.Common.MVVM.WPF.Attributes;

public static partial class MyAttachedProperties
{
 [AttachedProperty(DefaultValue = false)]
 public static bool IsHighlighted { get; set; }
}

// Usage in XAML:
// <Button local:MyAttachedProperties.IsHighlighted="True" />

WPF Commands

using OutWit.Common.MVVM.WPF.Commands;

public class MyViewModel
{
 public DelegateCommand SaveCommand { get; }

 public MyViewModel()
 {
 SaveCommand = new DelegateCommand(
 execute: _ => Save(),
 canExecute: _ => CanSave());
 }

 private void Save() { }
 private bool CanSave() => true;
}

Binding Utilities

Manual DependencyProperty registration (for when you can't use source generator):

using OutWit.Common.MVVM.WPF.Utils;

public class MyControl : Control
{
 public static readonly DependencyProperty TextProperty = 
 BindingUtils.Register<MyControl, string>(nameof(Text), "Default");

 public string Text
 {
 get => (string)GetValue(TextProperty);
 set => SetValue(TextProperty, value);
 }
}

Visual Tree Traversal

using OutWit.Common.MVVM.WPF.Utils;

// Find first child of specific type
var button = myPanel.FindFirstChildOf<Button>();

// Find with predicate
var redButton = myPanel.FindFirstChildOf<Button>(b => b.Background == Brushes.Red);

// Find all children
var allButtons = myPanel.FindAllChildrenOf<Button>();

// Find parent
var window = myButton.FindFirstParentOf<Window>();

BindingProxy for DataContext Access

<Window.Resources>
 <local:BindingProxy x:Key="Proxy" Data="{Binding}" />
</Window.Resources>

<DataGrid>
 <DataGrid.Columns>
 <DataGridTemplateColumn>
 <DataGridTemplateColumn.CellTemplate>
 <DataTemplate>
 
 <Button Command="{Binding Data.DeleteCommand, Source={StaticResource Proxy}}"
 CommandParameter="{Binding}" />
 </DataTemplate>
 </DataGridTemplateColumn.CellTemplate>
 </DataGrid.Columns>
 </DataGrid>
</Window.Resources>

StyledProperty Options

AttachedProperty Options

Migration from Old BindableAttribute

See for detailed instructions.

Quick summary:

1. Change [Bindable] to [StyledProperty]
2. Remove manual DependencyProperty declarations
3. Mark class as partial
4. Move options to attribute parameters

Legacy BindableAttribute (Deprecated)

The old BindableAttribute using AspectInjector is still available but deprecated:

[Obsolete("Use StyledPropertyAttribute instead")]
public class BindableAttribute : Attribute { }

Recommendation: Migrate to StyledPropertyAttribute for better IDE support and debugging.

Related Packages

• OutWit.Common.MVVM - Cross-platform base classes
• OutWit.Common.MVVM.Avalonia - Avalonia-specific implementation
• OutWit.Common.MVVM.Blazor - Blazor-specific implementation

License

Licensed under the Apache License, Version 2.0. See LICENSE.

Attribution (optional)

If you use OutWit.Common.MVVM.WPF in a product, a mention is appreciated (but not required), for example: "Powered by OutWit.Common.MVVM.WPF (https://ratner.io/)".

Trademark / Project name

"OutWit" and the OutWit logo are used to identify the official project by Dmitry Ratner.

You may:

• refer to the project name in a factual way (e.g., "built with OutWit.Common.MVVM.WPF");
• use the name to indicate compatibility (e.g., "OutWit.Common.MVVM.WPF-compatible").

You may not:

• use "OutWit.Common.MVVM.WPF" as the name of a fork or a derived product in a way that implies it is the official project;
• use the OutWit.Common.MVVM.WPF logo to promote forks or derived products without permission.