Today, we are releasing the .NET March 2021 Updates. These updates contains reliability and security improvements. See the individual release notes for details on updated packages.

You can download 5.0.4 , 3.1.13, 2.1.26 versions for Windows, macOS, and Linux, for x86, x64, Arm32, and Arm64.

• Installers and binaries: 5.0.4 | 3.1.13 | 2.1.26
• Release notes: 5.0.4 | 3.1.13 | 2.1.26
• Container images
• Linux packages: 5.0.4 | 3.1.13 | 2.1.26
• Release feedback/issues
• Known issues: 5.0 | 3.1 | 2.1  

These are the customer-reported issues addressed in 15.8.9:

• Added support for Xcode 10.1 in Visual Studio Tools for Xamarin.
• Updated the Xamarin.Forms template to Xamarin.Forms 3.3.0.
• Update 15.8.6 breaks Installer Projects.
• Internal Compiler error in VS15.8 msc1.cpp line 1518.
• Microsoft Visual Studio 2017 Installer Projects 0.8.8 and VS 15.8.6.
• SFINAE fails to detect matching overloaded function in preview VS preview 3 15.9.0.
• XAML Designer crash on Visual Studio close. 

We kindly ask you for your valuable input on the priorities for modernizing investments that the WPF team should focus on, as outlined in the roadmap document for 2023.

Please use thumbs up (no other emoji responses will be considered to avoid duplication) on options below which you would like us to prioritize.

C# for Beginners
Join Scott Hanselman and .NET Distinguished Engineer David Fowler as they teach us C# from the ground up! From Hello World to LINQ and more, Scott and David share C# lessons at a deep and leisurely pace. By the end you'll be ready to explore the Foundational C# Certification from FreeCodeCamp!

 

Exploring the Features of C# 11: The Modern Capabilities of a Vibrant Language [Webinar]
C# has evolved long since its introduction about 20 years ago. In this live-coding presentation, learn about the fascinating features of the most recent version of the language. We will explore the most interesting features, their power, and how we can benefit from them to create concise, expressive, and maintainable code. 

exception myError of int

try
// try code here
finally
//finally statement here

exception WrongSecond of int//یک exception تعریف می‌کنیم

let primes =
[ 2; 3; 5; 7; 11; 13; 17; 19; 23; 29; 31; 37; 41; 43; 47; 53; 59 ]

// یک تابع برای تست اینکه آیا ثانیه الان در لیست prime وجود دارد یا نه
let testSecond() =
try
let currentSecond = System.DateTime.Now.Second in

// شرط برای اینکه مشخص شود که ثانیه در لیست است یا خیر
if List.exists (fun x -> x = currentSecond) primes then

// اگر بود یک خطا تولید می‌شود
failwith "A prime second"

else

// اگر نیود یک استثنا از نوع wrongSecond پرتاب میشود
raise (WrongSecond currentSecond)

with
// catch کردن استثناها

WrongSecond x ->
printf "The current was %i, which is not prime" x

// تابعی برای نوشتن فایل
let writeToFile() =
//ابتدا فایل به صورت متنی ساخته می‌شود
let file = System.IO.File.CreateText("test.txt")
try
// متن مورد نظر در فایل نوشته می‌شود
file.WriteLine("Hello F# users")
finally
//فایل مورد نظر بسته می‌شود.این دستور حتی اگر در هنگام نوشتن فایل استثنا هم رخ بدهد اجرا خواهد شد
file.Dispose()

let getNumber msg =
    printf msg;
    try
        int32(System.Console.ReadLine())
    with
        | :? System.FormatException -> -1
        | :? System.OverflowException -> System.Int32.MinValue
        | :? System.ArgumentNullException -> 0

Here’s a summary of what’s new in this preview release:

• New Blazor WebAssembly loading page
• Blazor data binding get/set/after modifiers
• Blazor virtualization improvements
• Pass state using NavigationManager
• Additional System.Security.Cryptography support on WebAssembly
• Updated Angular and React templates
• gRPC JSON transcoding performance
• Authentication will use single scheme as DefaultScheme
• IFormFile/IFormFileCollection support for authenticated requests in minimal APIs
• New problem details service
• Diagnostics middleware updates
• New HttpResults interfaces 

Here’s what’s new in this preview release:

• .NET Hot Reload updates for dotnet watch
• ASP.NET Core SPA templates updated to Angular 11 and React 17
• Use Razor syntax in SVG foreignObject elements
• Specify null for Action and RenderFragment component parameters
• Reduced Blazor WebAssembly download size with runtime relinking
• Configurable buffer threshold before writing to disk in Json.NET output formatter
• Subcategories for better filtering of Kestrel logs
• Faster get and set for HTTP headers
• Configurable unconsumed incoming buffer size for IIS 

Here are 13 techniques and tools that prove the power of lazy programming. The next time the boss tells you it’s time to roll up your sleeves and lean into the console, head to the nap room instead.