adding working skeleton of WPF instructions

instructions/dotnet-wpf.instructions.md

@@ -0,0 +1,79 @@
+---
+description: '.NET WPF component and application patterns'
+applyTo: '**/*.xaml, **/*.cs'
+---
+
+## Summary
+
+These instructions guide GitHub Copilot to assist with building high-quality, maintainable, and performant WPF applications using the MVVM pattern. It includes best practices for XAML, data binding, UI responsiveness, and .NET performance.
+
+## Ideal project types
+
+- Desktop applications using C# and WPF
+- Applications following the MVVM (Model-View-ViewModel) design pattern
+- Projects using .NET 8.0 or later
+- UI components built in XAML
+- Solutions emphasizing performance and responsiveness
+
+## Goals
+
+- Generate boilerplate for `INotifyPropertyChanged` and `RelayCommand`
+- Suggest clean separation of ViewModel and View logic
+- Encourage use of `ObservableCollection<T>`, `ICommand`, and proper binding
+- Recommend performance tips (e.g., virtualization, async loading)
+- Avoid tightly coupling code-behind logic
+- Produce testable ViewModels
+
+## Example prompt behaviors
+
+### ✅ Good Suggestions
+- "Generate a ViewModel for a login screen with properties for username and password, and a LoginCommand"
+- "Write a XAML snippet for a ListView that uses UI virtualization and binds to an ObservableCollection"
+- "Refactor this code-behind click handler into a RelayCommand in the ViewModel"
+- "Add a loading spinner while fetching data asynchronously in WPF"
+
+### ❌ Avoid
+- Suggesting business logic in code-behind
+- Using static event handlers without context
+- Generating tightly coupled XAML without binding
+- Suggesting WinForms or UWP approaches
+
+## Technologies to prefer
+- C# with .NET 8.0+
+- XAML with MVVM structure
+- `CommunityToolkit.Mvvm` or custom `RelayCommand` implementations
+- Async/await for non-blocking UI
+- `ObservableCollection`, `ICommand`, `INotifyPropertyChanged`
+
+## Common Patterns to Follow
+- ViewModel-first binding
+- Dependency Injection using .NET or third-party containers (e.g., Autofac, SimpleInjector)
+- XAML naming conventions (PascalCase for controls, camelCase for bindings)
+- Avoiding magic strings in binding (use `nameof`)
+
+## Sample Instruction Snippets Copilot Can Use
+
+```csharp
+public class MainViewModel : ObservableObject
+{
+    [ObservableProperty]
+    private string userName;
+
+    [ObservableProperty]
+    private string password;
+
+    [RelayCommand]
+    private void Login()
+    {
+        // Add login logic here
+    }
+}
+```
+
+```xml
+<StackPanel>
+    <TextBox Text="{Binding UserName, UpdateSourceTrigger=PropertyChanged}" />
+    <PasswordBox x:Name="PasswordBox" />
+    <Button Content="Login" Command="{Binding LoginCommand}" />
+</StackPanel>
+```