GenerateAvaloniaDesignTimeConstructorAttribute

NexusLabs.Needlr.Avalonia

GenerateAvaloniaDesignTimeConstructorAttribute Class

Generates a parameterless constructor for Avalonia design-time XAML preview support.

public sealed class GenerateAvaloniaDesignTimeConstructorAttribute : System.Attribute

Inheritance System.Object 🡒 System.Attribute 🡒 GenerateAvaloniaDesignTimeConstructorAttribute

Example

[GenerateAvaloniaDesignTimeConstructor]
public sealed partial class MainWindow : Window
{
    private readonly ShellViewModel _viewModel;

    public MainWindow(ShellViewModel viewModel)
    {
        _viewModel = viewModel;
        InitializeComponent();
        DataContext = viewModel;
    }
}

Remarks

Apply this to a partial class that has a constructor with injectable parameters (the DI constructor). The source generator emits a parameterless constructor that: - Suppresses CS8618 (non-nullable fields not initialized) via #pragma - Throws System.InvalidOperationException if called at runtime outside Avalonia's design mode - Calls InitializeComponent() for the XAML previewer

At runtime, Needlr's richest-constructor selection ensures the DI constructor is used. The generated parameterless constructor exists solely for the Avalonia XAML designer/previewer.