TL;DR
This blog post is a compilation of the latest and greatest additions from the .NET 6 release. Also, I've created a coding story that will help you to learn new improvements.
Please check the coding story π:
https://codingstories.io/stories/6139f4a2f2cd3d0031cd8ef1/617b06b5d2ec28001acfe618
Also, see my blog post. It explains how to run .NET 6 inside devcontainer: https://nikiforovall.github.io/productivity/devcontainers/2021/10/14/devcontainer-for-dotnet6.html
β π Please note that the content below consists of excerpts from the actual coding story. Please check the coding story if you haven't already.
Part 1. C# 10
Full list of changes:
- https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-10
- https://devblogs.microsoft.com/dotnet/announcing-net-6-release-candidate-2/
Also, see:
- Every feature added in C# 10 with examples by NickChapsas https://www.youtube.com/watch?v=Vft4QDUpyWY&ab_channel=NickChapsas
- https://devblogs.microsoft.com/dotnet/new-dotnet-6-apis-driven-by-the-developer-community/
- https://www.infoworld.com/article/3608611/whats-new-in-microsoft-net-6.html
Global usings
global using global::System;
global using global::System.Collections.Generic;
global using global::System.IO;
global using global::System.Linq;
global using global::System.Net.Http;
global using global::System.Threading;
global using global::System.Threading.Tasks;
global using static System.Console;
global using static System.Math;
WriteLine(Sqrt(3 * 3 + 4 * 4));
$ dotnet run
5
Reference
- https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/using-directive#global-modifier
- https://docs.microsoft.com/en-us/dotnet/core/compatibility/sdk/6.0/implicit-namespaces#new-behavior
- https://www.hanselman.com/blog/implicit-usings-in-net-6
- https://dotnetcoretutorials.com/2021/08/31/implicit-using-statements-in-net-6/
File-scoped namespaces
// IProductRepository.cs
namespace MyNamespace;
public interface IProductRepository
{
Task<Product> GetProductAsync(int id);
}
public record class Product(int Id, string Name, ProductWarranty Warranty);
// Program.cs
using MyNamespace;
var repository = new ProductRepository();
var product = await repository.GetProductAsync(Parse(args[0]));
WriteLine(product);
$ dotnet run 12
Product { Id = 1, Name = Name, Warranty = OneYear }
Reference
- https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/namespace
- https://ardalis.com/dotnet-format-and-file-scoped-namespaces/
- https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/csharp-10.0/file-scoped-namespaces
Record structs
public record class Point(double X, double Y, double Z);
// public record class Point
// {
// public double X { get; init; }
// public double Y { get; init; }
// public double Z { get; init; }
// }
public readonly record struct Point2(double X, double Y, double Z);
// public record struct Point2
// {
// public double X { get; init; }
// public double Y { get; init; }
// public double Z { get; init; }
// }
public record struct Point3(double X, double Y, double Z);
// public record struct Point3
// {
// public double X { get; set; }
// public double Y { get; set; }
// public double Z { get; set; }
// }
Reference
Part 2. .NET API
β System.Numerics.BitOperations
Minimal API
// ================================================================
// Main Components
// ================================================================
// WebApplication
public static Microsoft.AspNetCore.Builder.WebApplicationBuilder CreateBuilder ();
// WebApplicationBuilder
public Microsoft.AspNetCore.Builder.WebApplication Build ();
// WebApplication
public void Run (string? url = default);
var builder = WebApplication.CreateBuilder(args);
var services = builder.Services;
services
.AddEndpointsApiExplorer()
.AddSwaggerGen();
var app = builder.Build();
app
.UseSwagger()
.UseSwaggerUI();
app.MapGet("ka/{pow}", (int pow) => IsPow2(pow));
app.Run();
$ dotnet run
Building...
info: Microsoft.Hosting.Lifetime[14]
Now listening on: https://localhost:7225
info: Microsoft.Hosting.Lifetime[14]
Now listening on: http://localhost:5069
info: Microsoft.Hosting.Lifetime[0]
Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
Hosting environment: Development
info: Microsoft.Hosting.Lifetime[0]
Content root path: D:\home\dev\codingstories\whats-new-in-dotnet6\MinimalAPI
Reference
- Minimal APIs at a glance by davidfowl https://gist.github.com/davidfowl/ff1addd02d239d2d26f4648a06158727
- Migration to ASP.NET Core in .NET 6 by davidfowl https://gist.github.com/davidfowl/0e0372c3c1d895c3ce195ba983b1e03d
- https://minimal-apis.github.io/
- https://andrewlock.net/series/exploring-dotnet-6/
- https://docs.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.builder.webapplicationbuilder?view=aspnetcore-6.0
- https://docs.microsoft.com/en-us/dotnet/api/microsoft.aspnetcore.builder.webapplication?view=aspnetcore-6.0
- https://github.com/martincostello/dotnet-minimal-api-integration-testing
- https://nikiforovall.github.io/dotnet/aspnetcore/2021/09/10/opinionated-minimal-api.html
LINQ Improvements
using Bogus;
var faker = new OrderFaker();
var orders = faker.Generate(100);
// ================================================================
Header("Chunking");
// ================================================================
foreach (var chunk in orders.Chunk(25))
{
var sum = chunk.Sum(o => o.Quantity);
WriteLine($"chunk[{chunk.Length}].Quantity={sum}");
}
Chunking
chunk[25].Quantity=154
chunk[25].Quantity=138
chunk[25].Quantity=119
chunk[25].Quantity=138
// ================================================================
Header("Index Support for ElementAt");
// ================================================================
var order1 = orders.ElementAt(^5);
WriteLine(order1);
Index Support for ElementAt
Order { OrderId = 15, Address = 604 Leffler Glens, Romaport, Cape Verde, Quantity = 2, Index = 96 }
// ================================================================
Header("Range Support for Take");
// ================================================================
var orders2 = orders.Take(^5..);
WriteLine(string.Join(Environment.NewLine, orders2));
Range Support for Take
Order { OrderId = 15, Address = 604 Leffler Glens, Romaport, Cape Verde, Quantity = 2, Index = 96 }
Order { OrderId = 8, Address = 35694 Cummings Ville, Turnerville, Republic of Korea, Quantity = 5, Index = 97 }
Order { OrderId = 13, Address = 8711 Vita Burgs, East Jamaalberg, Zambia, Quantity = 4, Index = 98 }
Order { OrderId = 83, Address = 11506 Skiles Curve, Lake Abbeychester, Suriname, Quantity = 8, Index = 99 }
Order { OrderId = 89, Address = 9444 Schamberger Burgs, Wisokyland, Costa Rica, Quantity = 2, Index = 100 }
// ================================================================
Header("Three way zipping");
// ================================================================
string[] a1 = { "1", "2", "3" };
string[] a2 = { "One", "Two", "Three" };
float[] a3 = { 1f, 2f, 3f };
foreach ((string i, string i2, float i3) in a1.Zip(a2, a3))
{
WriteLine($"{i}-{i2}-{i3}");
}
Three-way zipping
1-One-1
2-Two-2
3-Three-3
// ================================================================
Header("Default Parameters for Common Methods");
// ================================================================
var order2 = orders.FirstOrDefault(
o => o.Address.Contains("Odesa"), defaultValue: orders.ElementAt(^10));
WriteLine(order2);
Default Parameters for Common Methods
Order { OrderId = 14, Address = 49026 Huels Groves, Armandville, Bhutan, Quantity = 3, Index = 91 }
// ================================================================
Header("Avoiding Enumeration with TryGetNonEnumeratedCount");
// ================================================================
if (orders.TryGetNonEnumeratedCount(out int count))
WriteLine($"The count is {count}");
Avoiding Enumeration with TryGetNonEnumeratedCount
The count is 100
// ================================================================
Header("MaxBy and MinBy");
// ================================================================
WriteLine(orders.MaxBy(o => o.Quantity));
MaxBy and MinBy
Order { OrderId = 16, Address = 30901 Madilyn Meadow, Lake Marlenfort, Malawi, Quantity = 10, Index = 2 }
Reference
- 7 awesome improvements for LINQ in .NET 6 by NickChapsas https://www.youtube.com/watch?v=sIXKpyhxHR8&t=1s&ab_channel=NickChapsas
Parallel.ForEachAsync
β Task.WaitAsync
β Random.Shared
public static Task ForEachAsync<TSource>(
IAsyncEnumerable<TSource> source,
Func<TSource, CancellationToken, ValueTask> body);
public static Task ForEachAsync<TSource>(
IEnumerable<TSource> source,
Func<TSource, CancellationToken, ValueTask> body);
await Parallel.ForEachAsync(Generate(), Handle)
.WaitAsync(TimeSpan.FromMilliseconds(200))
.ContinueWith(Report);
static async IAsyncEnumerable<int> Generate()
{
while (true)
{
var delay = Random.Shared.Next(100);
WriteLine($"Issued {delay}");
await Task.Delay(delay);
yield return delay;
}
}
static async ValueTask Handle(int i, CancellationToken ct)
{
await Task.Delay(i, ct);
WriteLine($"Handled {i}");
}
static void Report(Task t) => WriteLine(
$"Finished at: {DateTime.Now:T}, task.Status {t.Status}");
$ dotnet run
Issued 56
Issued 23
Issued 81
Handled 23
Handled 56
Issued 75
Finished at: 10:59:08 PM, task.Status Faulted
Reference
PeriodicTimer
β ArgumentNullException.ThrowIfNull
using var timer = new PeriodicTimer(TimeSpan.FromSeconds(1));
while (await timer.WaitForNextTickAsync())
{
LogEntry? l = Random.Shared.Next(128) is int r && IsPow2(r)
? default
: new(r);
ProcessLogEntry(l);
}
static void ProcessLogEntry(LogEntry? entry)
{
ArgumentNullException.ThrowIfNull(entry, nameof(entry));
WriteLine(entry);
}
public record class LogEntry(int Value);
$ dotnet run
LogEntry { Value = 104 }
LogEntry { Value = 115 }
LogEntry { Value = 21 }
LogEntry { Value = 110 }
LogEntry { Value = 106 }
LogEntry { Value = 63 }
LogEntry { Value = 81 }
Unhandled exception. System.ArgumentNullException: Value cannot be null. (Parameter 'entry')
at System.ArgumentNullException.Throw(String paramName)
at System.ArgumentNullException.ThrowIfNull(Object argument, String paramName)
at Program.<<Main>$>g__ProcessLogEntry|0_0(LogEntry entry) in PeriodicTimer\Program.cs:line 18
at Program.<Main>$(String[] args) in PeriodicTimer\Program.cs:line 12
at Program.<Main>(String[] args)
Priority Queue
var queue = new PriorityQueue<Job, int>(ReverseComparer<int>.Default);
foreach (var i in 10)
{
var p = Random.Shared.Next(100);
queue.Enqueue(new($"Job{i}", p), p);
}
using var timer = new PeriodicTimer(TimeSpan.FromMilliseconds(500));
while (await timer.WaitForNextTickAsync())
{
if (!queue.TryDequeue(out var job, out _))
break;
WriteLine(job);
}
public record struct Job(string Name, int Priority);
public sealed class ReverseComparer<T> : IComparer<T>
{
public static readonly ReverseComparer<T> Default = new(Comparer<T>.Default);
public static ReverseComparer<T> Reverse(IComparer<T> comparer) =>
new ReverseComparer<T>(comparer);
private readonly IComparer<T> comparer = Default;
private ReverseComparer(IComparer<T> comparer) =>
this.comparer = comparer;
public int Compare(T? x, T? y) => comparer.Compare(y, x);
}
public static class ProduceNumericEnumeratorExtensions
{
public static IEnumerator<int> GetEnumerator(this int number)
{
for (var i = 0; i < number; i++)
{
yield return i;
}
}
}
$ dotnet run
Job { Name = Job1, Priority = 75 }
Job { Name = Job5, Priority = 66 }
Job { Name = Job2, Priority = 61 }
Job { Name = Job0, Priority = 58 }
Job { Name = Job4, Priority = 53 }
Job { Name = Job9, Priority = 34 }
Job { Name = Job7, Priority = 34 }
Job { Name = Job3, Priority = 29 }
Job { Name = Job8, Priority = 17 }
Job { Name = Job6, Priority = 8 }
Reference
- https://docs.microsoft.com/en-us/dotnet/api/system.collections.generic.priorityqueue-2?view=net-6.0
- https://dotnetcoretutorials.com/2021/03/17/priorityqueue-in-net/
DateOnly and TimeOnly
DateOnly date = DateOnly.MinValue;
Log(date, nameof(date)); //Outputs 01/01/0001 (With no Time)
TimeOnly time = TimeOnly.MinValue;
Log(time, nameof(time)); //Outputs 12:00 AM
TimeOnly startTime = TimeOnly.Parse("11:00 PM");
var hoursWorked = 2;
var endTime = startTime.AddHours(hoursWorked);
Log(endTime, nameof(endTime)); //Outputs 1:00 AM
var isBetween = TimeOnly.Parse("12:00 AM").IsBetween(startTime, endTime);
Log(isBetween, nameof(isBetween)); //Outputs true.
static void Log<T>(T value, string name = "") => WriteLine($"{name} {value}");
$ dotnet run
date 1/1/0001
time 12:00 AM
endTime 1:00 AM
isBetween True
System.Text.Json
// ================================================================
Header("Serialization Notification");
// ================================================================
string invalidOrderJson = "{}";
var success = IgnoreErrors(() => JsonSerializer.Deserialize<Order2>(invalidOrderJson));
WriteLine($"Exception thrown: {!success}");
// IJsonOnDeserialized, IJsonOnDeserializing, IJsonOnSerialized, IJsonOnSerializing
public record class Order2 : Order, IJsonOnDeserialized
{
public void OnDeserialized() => this.Validate();
private void Validate()
{
if (this.OrderId <= 0)
throw new ArgumentException();
}
}
public record class Order
{
public int OrderId { get; init; }
public string Address { get; init; }
public int Quantity { get; init; }
}
static bool IgnoreErrors(Action operation)
{
if (operation == null)
return false;
try
{
operation.Invoke();
}
catch
{
return false;
}
return true;
}
$ dotnet run
Serialization Notification
Exception thrown: True
// ================================================================
Header("Property Ordering");
// ================================================================
Order3 order = new()
{
OrderId = 1,
Address = "Address",
Quantity = 1,
Comments = new() { "Cool", "Awesome" }
};
var serializedOrder = JsonSerializer.Serialize(order, options);
WriteLine(serializedOrder);
public record class Order3
{
[JsonPropertyOrder(-1)]
public int OrderId { get; init; }
[JsonPropertyOrder(1)]
public string Address { get; init; }
[JsonPropertyOrder(2)]
public int Quantity { get; init; }
[JsonPropertyOrder(99)]
public List<string> Comments { get; init; }
}
$ dotnet run
Property Ordering
{
"OrderId": 1,
"Address": "Address",
"Quantity": 1,
"Comments": [
"Cool",
"Awesome"
]
}
// ================================================================
Header("IAsyncEnumerable support && Working with Streams");
// ================================================================
var data = new { Data = RangeAsync(1, 5) };
// SerializeAsync
using var stream = new MemoryStream();
await JsonSerializer.SerializeAsync(stream, RangeAsync(1, 5), options);
stream.Position = 0;
// DeserializeAsyncEnumerable
await foreach (var i in JsonSerializer.DeserializeAsyncEnumerable<int>(stream, options))
{
WriteLine(i);
}
static async IAsyncEnumerable<int> RangeAsync(int start, int count)
{
for (int i = 0; i < count; i++)
{
await Task.Delay(i);
yield return start + i;
}
}
$ dotnet run
1
2
3
4
5
// ================================================================
Header("Working with JSON DOM");
// ================================================================
// Parse
var node = JsonNode.Parse(serializedOrder);
WriteLine($"OrderId: {node["OrderId"].GetValue<int>()}");
WriteLine($"Order.Comments[0]: {node["Comments"][0].GetValue<string>()}");
// Create DOM Object via API
var jObjectOrder = new JsonObject
{
["OrderId"] = 1,
["Discounts"] = new JsonArray(
new JsonObject
{
["DiscountId"] = 1,
["Value"] = .05,
},
new JsonObject
{
["DiscountId"] = 2,
["Value"] = .1,
}
),
};
WriteLine(jObjectOrder.ToJsonString(options));
OrderId: 1
Order.Comments[0]: Cool
{
"OrderId": 1,
"Discounts": [
{
"DiscountId": 1,
"Value": 0.05
},
{
"DiscountId": 2,
"Value": 0.1
}
]
}
Summary
Thank you very much. I hope you find this blog post useful π.
Top comments (1)
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