Microsoft Web Template Studio (WebTS) is a Visual Studio Code Extension that accelerates the creation of new web applications using a wizard-based experience. 

ASP.NET Core 1.0 is the ground-up rewrite of ASP.NET, MVC and Web API, bringing a new paradigm in building web applications and APIs in .NET. With this rewrite brought new techniques in building SOLID applications, and updated some existing patterns and tools.
In this session, we'll take a lap around some of the major extension points of ASP.NET Core 1.0, walking through how these features can help us build cleaner, more maintainable systems. We'll cover web APIs, traditional MVC applications, controllers, views, filters, dependency injection, tag helpers and more. With a SOLID foundation, our ASP.NET Core applications will be dead simple to build and maintain.
 

We’re proud to announce the release of PowerShell 7.1, the latest major update to PowerShell 7. This release includes a number of improvements and fixes that build on top of the PowerShell 7.0 release in March and the recent GA release of .NET 5.  

Short Videos Demonstrating What’s New in Visual Studio 2015 Preview for C#, F#, and VB

 dotnet new globaljson --sdk-version 3.0.100-preview7-012821

$urlCurrent = "https://download.visualstudio.microsoft.com/download/pr/41e4c58f-3ac9-43f6-84b6-f57d2135331a/3691b61f15f1f5f844d687e542c4dc72/dotnet-sdk-3.0.100-preview7-012821-win-x64.zip"
$env:DOTNET_INSTALL_DIR = "C:\Program Files\dotnet\sdk"
mkdir $env:DOTNET_INSTALL_DIR -Force | Out-Null
$tempFileCurrent = [System.IO.Path]::Combine([System.IO.Path]::GetTempPath(), [System.IO.Path]::GetRandomFileName())
(New-Object System.Net.WebClient).DownloadFile($urlCurrent, $tempFileCurrent)
Add-Type -AssemblyName System.IO.Compression.FileSystem; [System.IO.Compression.ZipFile]::ExtractToDirectory($tempFileCurrent, $env:DOTNET_INSTALL_DIR)
$env:Path = "$env:DOTNET_INSTALL_DIR;$env:Path"

Bootstrap Icons v1.11.0 has arrived with 100 new icons—including new floppy disk icons, additional brand icons, new person icons, new emojis, some birthday cake, a few new science icons, and more. We’re now at over 2,000 icons! 

public class User
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }

public class UserService : IUserService
    {
        private IList<User> _userData;

        public UserService()
        {
            _userData = new List<User>
            {
                new User {Id = 1,Name = "ali"},
                new User {Id = 2,Name = "Karim"}
            };
        }

        public User GetById(int id)
        {
            return _userData.FirstOrDefault(x => x.Id == id);
        }
    }  

public class UserController : Controller
    {
        private readonly IUserService _userService;

        public UserController(IUserService  userService)
        {
            _userService = userService;
        }
        public ActionResult Details(int id)
        {
            var user=_userService.GetById(3); // این متد ممکن است مقداری برگرداند و یا مقدار نال برگرداند                           
            if( user == null)
                 return HttpNotFound();    
            return View(user);  
        }
    }

 public ActionResult Details(int id)
        {
            var user = _userService
                            .GetById(3)
                            .DefaultIfEmpty(new User())
                            .Single();
            return View(user);
        }

public class Option<T> : IEnumerable<T>
    {
        private readonly T[] _data;

        private Option(T[] data)
        {
            _data = data;
        }

        public static Option<T> Create(T element) => new Option<T>(new[] { element });

        public static Option<T> CreateEmpty() => new Option<T>(new T[0]);

        public IEnumerator<T> GetEnumerator() => ((IEnumerable<T>) _data).GetEnumerator();

        IEnumerator IEnumerable.GetEnumerator() => this.GetEnumerator();
    }

 public class UserService : IUserService
    {
       ...
       ...
       public Option<User> GetById(int id)
        {
            var user = _userData.FirstOrDefault(x => x.Id == id);
            return user == null ? Option<User>.CreateEmpty() : Option<User>.Create(user);
        }
    }

 public class UserController : Controller
    {
       ...
       ...
       public ActionResult Details(int id)
        {
            var user = _userService
                            .GetById(3)
                            .DefaultIfEmpty(new User())
                            .Single();
            return View(user);
        }
    }

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.0</TargetFramework>
    <LangVersion>latest</LangVersion>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="System.Memory" Version="4.4.0-preview1-25305-02" />
  </ItemGroup>
</Project>

    static class NameValidatorUsingString
    {
        public static bool IsValidName(string name)
        {
            if (name.Length < 2)
                return false;

            if (char.IsLetter(name[0]))
                return true;

            return false;
        }
    }

string fullName = "User 1";
string firstName = fullName.Substring(0, 4);
NameValidatorUsingString.IsValidName(firstName);

char[] anotherFullName = { 'A', 'B' };

NameValidatorUsingString.IsValidName(anotherFullName);

NameValidatorUsingString.IsValidName(new string(anotherFullName));

    static class NameValidatorUsingSpan
    {
        public static bool IsValidName(ReadOnlySpan<char> name)
        {
            if (name.Length < 2)
                return false;

            if (char.IsLetter(name[0]))
                return true;

            return false;

        }
    }

ReadOnlySpan<char> fullName = "User 1".AsSpan();
ReadOnlySpan<char> firstName = fullName.Slice(0, 4);
NameValidatorUsingSpan.IsValidName(firstName);

char[] anotherFullName = { 'A', 'B' };
NameValidatorUsingSpan.IsValidName(anotherFullName);

var arr = new byte[10];
Span<byte> bytes = arr; // Implicit cast from T[] to Span<T>

Span<byte> slicedBytes = bytes.Slice(start: 5, length: 2);
slicedBytes[0] = 42;
slicedBytes[1] = 43;
slicedBytes[2] = 44; // Throws IndexOutOfRangeException
bytes[2] = 45; // OK

var array = new byte[100];
Span<byte> interiorRef1 = array.AsSpan().Slice(start: 20);

Span<byte> interiorRef2 = new Span<byte>(array: array, start: 20, length: array.Length - 20);

class Impossible
{
   Span<byte> field;
}

static async Task<int> ChecksumReadAsync(Memory<byte> buffer, Stream stream)
{
   int bytesRead = await stream.ReadAsync(buffer);
   return Checksum(buffer.Span.Slice(0, bytesRead));
   // Or buffer.Slice(0, bytesRead).Span
}