dotnet wpf.instructions

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>