Mvvm Toolkit Di

What it does

When your agent uses it

• Mobile work in your project

Example prompts

• “/mvvm-toolkit-di”

Workflow steps

6 steps, taken from the first numbered list in SKILL.md.

1. 1Ioc.Default.GetService() inside a VM constructor. Hides the
2. 2Everything Singleton. A "per-document" VM registered as singleton
3. 3Multiple BuildServiceProvider() calls. Each call is a fresh
4. 4Capturing IServiceProvider in long-lived objects. Indicates a
5. 5No scope validation in development. Use Host.CreateDefaultBuilder()
6. 6Resolving scoped services from the root provider. They're

What it can do on your machine

Read from SKILL.md and the folder at commit 727ff2e. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are csharp).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • learn.microsoft.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Mvvm Toolkit Di loads about 2.3k tokens when it runs, and up to ~4.4k if it reads all its reference files. Until then it costs about 101 tokens; SKILL.md has 620 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~101

When it runs · the whole SKILL.md, loaded when a task matches

~2.3k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~4.4k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from github/awesome-copilot at commit 727ff2e, republished under its MIT licence (© github). 620 words, ~2,339 tokens.

name

mvvm-toolkit-di

description

Wire CommunityToolkit.Mvvm ViewModels into Microsoft.Extensions.DependencyInjection. Covers the .NET Generic Host composition root, constructor injection, service lifetimes (Singleton / Transient / Scoped), IMessenger registration, resolving ViewModels in Views, keyed services, testing seams, and the legacy Ioc.Default escape hatch. Use across WPF, WinUI 3, .NET MAUI, Uno, and Avalonia.

using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using CommunityToolkit.Mvvm.Messaging;

public partial class App : Application
{
    public IHost Host { get; }

    public App()
    {
        Host = Microsoft.Extensions.Hosting.Host
            .CreateDefaultBuilder()
            .ConfigureServices((_, services) =>
            {
                services.AddSingleton<IFilesService, FilesService>();
                services.AddSingleton<ISettingsService, SettingsService>();
                services.AddSingleton<IMessenger>(WeakReferenceMessenger.Default);

                services.AddSingleton<ShellViewModel>();
                services.AddTransient<ContactViewModel>();
                services.AddTransient<EditorViewModel>();
            })
            .Build();
    }

    public static T GetService<T>() where T : class =>
        ((App)Current).Host.Services.GetRequiredService<T>();
}

var services = new ServiceCollection();
services.AddSingleton<IFilesService, FilesService>();
services.AddTransient<ContactViewModel>();
ServiceProvider provider = services.BuildServiceProvider();

public sealed partial class ContactViewModel(
    IFilesService files,
    IMessenger messenger,
    ILogger<ContactViewModel> logger)
    : ObservableRecipient(messenger)
{
    [ObservableProperty]
    private string? name;

    [RelayCommand]
    private async Task SaveAsync()
    {
        logger.LogInformation("Saving {Name}", Name);
        await files.SaveAsync(Name!);
    }
}

services.AddSingleton<ShellViewModel>();   // 1 instance for app lifetime
services.AddTransient<NoteViewModel>();    // new instance per resolve
services.AddScoped<DialogService>();       // 1 per scope (rare)

public sealed partial class ContactPage : Page
{
    public ContactViewModel ViewModel { get; }

    public ContactPage()
    {
        ViewModel = App.GetService<ContactViewModel>();
        InitializeComponent();
    }
}

services.AddSingleton<IMessenger>(WeakReferenceMessenger.Default);
// or
services.AddSingleton<IMessenger>(StrongReferenceMessenger.Default);

public sealed partial class MyViewModel(IMessenger messenger)
    : ObservableRecipient(messenger) { }

services.AddKeyedSingleton<IExporter, CsvExporter>("csv");
services.AddKeyedSingleton<IExporter, JsonExporter>("json");

public sealed partial class ExportViewModel(
    [FromKeyedServices("csv")] IExporter csvExporter,
    [FromKeyedServices("json")] IExporter jsonExporter)
    : ObservableObject { /* ... */ }

[Fact]
public async Task Save_calls_files_service()
{
    var files = new Mock<IFilesService>();
    var messenger = new WeakReferenceMessenger();
    var logger = NullLogger<ContactViewModel>.Instance;

    var vm = new ContactViewModel(files.Object, messenger, logger)
    {
        Name = "Ada"
    };

    await vm.SaveCommand.ExecuteAsync(null);

    files.Verify(f => f.SaveAsync("Ada"), Times.Once);
}

Ioc.Default.ConfigureServices(
    new ServiceCollection()
        .AddSingleton<IFilesService, FilesService>()
        .AddTransient<ContactViewModel>()
        .BuildServiceProvider());

var files = Ioc.Default.GetRequiredService<IFilesService>();

© github, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file (references) in skills/mvvm-toolkit-di of github/awesome-copilot.

• SKILL.md
• references/dependency-injection.md

Open the folder on GitHubat commit 727ff2e

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in github/awesome-copilot, which our catalogue first saw on October 7, 2026.

• boshi-xixixi/TraeSkill.trae/Skills/.agents/skills/mvvm-toolkit-di