MSDN .NET Framework Code Samples

ASP.NET Core

Building Web APIs with Minimal APIs

Learn how to create efficient and lightweight web APIs using ASP.NET Core's Minimal API feature.

ASP.NET Core Web API C# Beginner


// Program.cs
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/", () => "Hello World!");

app.MapGet("/api/products", () => new List<object>
{
    new { Id = 1, Name = "Laptop", Price = 1200.00 },
    new { Id = 2, Name = "Keyboard", Price = 75.00 }
});

app.Run();

WPF

Data Binding with MVVM Pattern

Implement the Model-View-ViewModel (MVVM) pattern for robust WPF application design, focusing on effective data binding.

WPF MVVM XAML C# Intermediate


// ViewModel.cs
public class MyViewModel : INotifyPropertyChanged
{
    private string _message;
    public string Message
    {
        get => _message;
        set
        {
            _message = value;
            OnPropertyChanged(nameof(Message));
        }
    }
    // ... INotifyPropertyChanged implementation ...
}

// MainWindow.xaml
<Window ...>
    <Window.DataContext>
        <local:MyViewModel />
    </Window.DataContext>
    <TextBlock Text="{Binding Message}" />
</Window>

Entity Framework Core

Code-First Approach to Database Development

Build your data model in code and let Entity Framework Core generate your database schema using the Code-First approach.

EF Core Database Code-First C# Intermediate


// DbContext.cs
public class BloggingContext : DbContext
{
    public DbSet<Blog> Blogs { get; set; }
    public DbSet<Post> Posts { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer("Server=(localdb)\\mssqllocaldb;Database=BloggingDB;Trusted_Connection=True;");
    }
}

// Model.cs
public class Blog
{
    public int BlogId { get; set; }
    public string Url { get; set; }
    public virtual ICollection<Post> Posts { get; set; }
}

Xamarin.Forms

Creating Cross-Platform Mobile UIs

Develop native mobile applications for iOS, Android, and Windows with a single shared C# codebase.

Xamarin.Forms Mobile Cross-Platform C# Beginner


// MainPage.xaml
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="MyMobileApp.MainPage">
    <StackLayout Padding="20">
        <Label Text="Welcome to Xamarin.Forms!"
               VerticalOptions="Center"
               HorizontalOptions="Center" />
        <Button Text="Click Me" Clicked="OnButtonClicked" />
    </StackLayout>
</ContentPage>

LINQ

Advanced Querying with LINQ

Master Language Integrated Query (LINQ) to perform powerful data manipulation and querying directly in your C# code.

LINQ C# Data Query Intermediate


// Sample data
var numbers = new List<int> { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

// Filter and sort even numbers greater than 3
var query = from num in numbers
            where num % 2 == 0 && num > 3
            orderby num
            select num;

foreach (var number in query)
{
    Console.WriteLine(number);
}
// Output: 4, 6, 8

.NET MAUI

Getting Started with .NET MAUI

Build native .NET applications for Windows, macOS, iOS, and Android from a single C# codebase with .NET MAUI.

.NET MAUI Cross-Platform Mobile Desktop C# Beginner


// App.xaml.cs
public partial class App : Application
{
    public App()
    {
        InitializeComponent();
        MainPage = new NavigationPage(new Views.HomePage());
    }
}

// HomePage.xaml
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="MyMauiApp.Views.HomePage"
             Title="Home">
    <VerticalStackLayout Spacing="10" Padding="20">
        <Label Text="Welcome to .NET MAUI!" />
        <Button Text="Navigate" Clicked="OnNavigateClicked" />
    </VerticalStackLayout>
</ContentPage>