Dotnet-Wpf

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

public class MainViewModel : ObservableObject
{
    [ObservableProperty]
    private string userName;

    [ObservableProperty]
    private string password;

    [RelayCommand]
    private void Login()
    {
        // Add login logic here
    }
}

<StackPanel>
    <TextBox Text="{Binding UserName, UpdateSourceTrigger=PropertyChanged}" />
    <PasswordBox x:Name="PasswordBox" />
    <Button Content="Login" Command="{Binding LoginCommand}" />
</StackPanel>