using-wpf-behaviors-triggers

What problem does it solve? Adding interactivity to WPF XAML often forces developers to write event handlers in code-behind, breaking MVVM separation and making UI logic hard to reuse. This Skill provides patterns for wiring events, data conditions, and reusable behaviors entirely in XAML using the Microsoft.Xaml.Behaviors.Wpf library. ## Core Features & Use Cases - EventTrigger and InvokeCommandAction: Bind UI events like Click or SelectionChanged directly to ViewModel commands, with optional event-args passing. - DataTrigger and ChangePropertyAction: React to bound property values by changing UI properties without code-behind. - Custom Behaviors and TriggerActions: Create reusable Behavior<T> and TriggerAction<T> classes with DependencyProperties, including drag-and-drop and focus behaviors. - Use Case: You need a TextBox that selects all text on focus and a Border that accepts dropped files, both bound to ViewModel commands. This Skill shows the exact XAML and C# behavior classes to implement both without touching code-behind. ## Quick Start Ask the AI to add an EventTrigger with InvokeCommandAction to a WPF Button so its Click event invokes a ViewModel command using Microsoft.Xaml.Behaviors.Wpf.