Many benchmarks that are using ArrayPool, or more specificly ArryPool<T>.Shared, are not actually measuring a "real" scenarion or the benchmark is flawed in some way. Let's examine a bit on what is going on.
You need some advice around Random? Sure there is something on LinkedIn for that. Let's have a look.
In this - somewhat technical and barely usable - blog post, we will have a look at inlining and structs in C#. And how they can optimize performance in some interesting ways.
This is a very small blog post on why you should use CancellationTokens in your API.
Another day, another dollar. LinkedIn has the tips for you! Performance, performance! Let's get right into it.
For a lack of a better title, this blog post shows a database improvement that helped me quite a bit and what to do to make it work.
Did you ever wonder if there is a noticeable difference between:
List<int> a = [1, 2, 3];
// And
List<int> b = new() {1,2,3};
Let's find out:
Architectural Unit tests are nice to constraint your system (like which parts of your application can access other parts of your application). This blog post is not about that - that is covered a lot in the internet. No, I want to show what I did in a recent project: Checking if all controllers do use CancellationToken and some other entities are sealed.
Some while ago I was explaining what "Lowering" is. And the interesting part is that List behaves differently like an array while also a List is backed by an array. But why?
Last year I wrote an article about how ToListAsync was slow in Entity Framework titled: "Be careful with ToListAsync and ToArrayAsync in Entity Framework Core". Things have evolved since then, so let's celebrate!
Did you ever try to have a switch expression in Blazor? Yes, and did it go well? Sometimes not. Let's see why!
As every year, the dotnet team adjusted the runtime and libraries to improve performance. So let's go over some of the highlights. I will link the corresponding blog post or GitHub issue for each item, so you can read more about it if you are interested.
And of course: You will find the benchmarks at the end of the article.
If you want to be up to date with dotnet development, you can obviously follow the official blogs from Microsoft and release notes. But what if you want to pick into the future or smaller details that aren't released or covered? Then let's go to GitHub!
If we have a List<T> and an IList<T>, enumerating over the List<T> is faster than enumerating over the IList<T>. Why is that?
For good reasons, many folks don't want to use reflection. Since .NET 8, we have a better way of dealing with this in most of the cases (when known in advance). But we can go the opposite: Make it even unsafer for a tiny bit performance!
In C# we have many nice guards sitting on top of static exceptions classes like ArgumentNullException, ArgumentOutOfRangeException, etc: As ArgumentException.ThrowIfNullOrEmpty, ArgumentException.ThrowIfNullOrWhiteSpace. Now we can extend them easily!
The dotnet documentation gets hints about using GitHub Copilot. Is this an ad? And can we expect more in the future?
New dotnet version means new features and improvements. There is a nice update to the HttpClient class in .NET 10.
With the latest preview: .NET 10 preview 3, we did get an overhaul on extensions. It might enable some nice tricks in the future.
Sometimes you want to have a custom 404 page - and since .NET 8 and "Blazor WebApps" the <NotFound> tag of the Router doesn't work anymore, so let's create a custom page for that.
Long title - short intro? Well - I recently came across my own stupidity and wanted to display that to the world. Basically, how to dynamically selecting a column with Entity Framework.
Tailwind version 4 was just released. With the new CLI, it is just so much easier to use tailwindcss with Blazor. So in this post, I will show you how to use the new CLI to create a new Blazor project with Tailwind v4.
Short disclaimer: If you still want to use version 3, I already wrote an article about this some time ago: "Blazor with TailwindCSS".
During my recent browsing on LinkedIn I saw that question: IEnumerable vs IEnumerator in C#: One is 2x Faster – Which One?
Naturally, I was very suspicious. So let's find out what is going on here.
Very small update - as the work on .NET 10 starts - or better - continues with full force, I did update the LINQ MindMap.
The .NET provided DI container has some means to check if the container can be created. This is useful to ensure that all dependencies can be resolved and that the container is correctly configured. Let's have a quick look.
Did you ever ask yourself: When will the good ol' .NET Framework retire? The short answer: I don't know, but we can make a good guess!
Almost all applications are using CORS (Cross-Origin Resource Sharing) to allow the client to access the resources from the server. When the client sends a request to the server, the server will respond with the Access-Control-Allow-Origin header to allow the client to access the resources.
Fabian Gosebrink and I finally launch our new website: developer-academy.ch. A website meant for developers that want to level up their skills!
Debugging is important, and it's often useful to be able to inspect the state of objects in the debugger. However sometimes you're working with 3rd party types that don't have any debugging capabilities, so you can't see their internal state easily. In this blog post we will have a look on how to equip 3rd party types with debugging capabilities.
Recently, there were two new features merged in .NET 10 I think are small little quality of life improvements: Avoid Blocking on startup with BackgroundServices and a new string comparer.
LINQ has a Join operator, that basically translates to something like a SQL INNER JOIN. There is no built in operator for a LEFT JOIN in LINQ, but you can achieve the same result by using a combination of GroupJoin, SelectMany and DefaultIfEmpty. But there is a chance that this might change in the future, as there is a proposal to add a LeftJoin operator in .net 10.
Just as a heads up: This blog post will probably bring you 0 value in your daily life - well, maybe a short smile. Let's put ValueTuple to its extreme!
Ahhhh dear LinkedIn - a pool of gems where everyone is expert in everything. Over the time I collected some trophies from there and today I want to discuss one of them: "Always use early returns".
I already showcased a simple modal dialog in a previous post. However, the dialog was not awaitable. In this post, I'll show you how to create an awaitable modal dialog.
Today, we are going to benchmark the performance of the Minimal API in ASP.NET 9 (and for reference against ASP.NET 8 as well) against the classic Controllers. We will test a few scenarios and check how the performance of the Minimal API compares to the classic Controllers. Let's get right into it!
I know that there is a lot of fuse about TUnit and I am here writing about xUnit. I might cover TUnit in the future, but for now, the topic is the v3 prerelease of xUnit!
Join us for an exciting seminar with Fabian Gosebrink about .NET 8, Nx, and Angular! Learn the latest trends and best practices. More details: here
In async code it is very common to pass a CancellationToken to the method that is being awaited. This allows the caller to cancel the operation if it is no longer needed. But this will lead to some ceremonial code that is repeated in every method. In this article I will show you how to manage CancellationToken in a central service in ASP.NET.
I came across a very annoying "issue" with LINQ joins (left joins) in Entity Framework where the compiler drove me nuts!
I am a great fan of API tests. I do like to utilize the WebApplicationFactory for this. I even wrote some articles about this in the past "Introduction to WebApplicationFactory". But what if we need to "mock" HttpClient calls inside our tests?
I recently came across the FormattableStringFactory to create dynamic FormattableString instances. This is a very useful feature in combination with safe SQL queries and the SqlQuery method of Entity Framework Core.
The .NET team has been working on a new experiment called async2, which is a new implementation of the async/await pattern that is designed to be more efficient and more flexible than the current implementation. It started with green threads and ended with an experiment that moves async and await to the runtime. This post will cover the journey of async2 and the conclusion of the experiment.
Even though it was introduced in .NET 7, I came across recently the AsParametersAttribute. Let's have a look what it is good for.
.NET is big, very big! So how many API's does it have? Let's find out!
You often here that the async/await keywords leads to a state machine. But what does that mean? Let's discuss this with a simple example.
I came across a recent LinkedIn post about the let statement in LINQ and it's performance implication. And in typically influencer fashion it out right claimed that using let in LINQ is a bad idea and should be avoided. But is it a bad idea?
.NET natively knows UUID v4 aka Guid.NewGuid(). But with preview 7 we get Version 7 of UUID's natively.
In this blog post, I will show you how to use GitHub Codespaces to make it easier for contributors to get started on your open-source project. We will set up a codespace for a .NET repository and configure it to install the required dependencies and tools.
The next preview (preview 6) will bring a new type ReadOnlySet<T>. This is a read-only set that is similar to ReadOnlyCollection<T>. Let's see how it works and why it was introduced.
The last update of NCronJob was some time ago - and as always, there are some new features in the meantime. So here we are, let's go through to highlight them!
Have you ever asked yourself if your EF LINQ queries are susceptible to SQL injection attacks? Either because you are querying some user data from a text field or directly taking whatever your API hits against the database?
If you call HttpClient.GetAsync or HttpClient.PostAsync and then await the result, does the await wait only for the headers to be received or does it wait for the body to be received? Let's find out!
The StringBuilder class is used to create mutable sequences of characters. Strings are immutable, so if you need to perform multiple operations on a string, it is better to use a StringBuilder instead of a string. This is especially useful when you need to concatenate a large number of strings. But there is more magic to it, especially when we go BIG!
In today's short post, I will show you how to cancel a Task with multiple inputs (aka multiple CancellationTokens) using CancellationTokenSource and CancellationTokenSource.CreateLinkedTokenSource.
I made a memory dump in my simplest console application and there are a bunch of exception instances around, what is going on? Let’s see in this blog post, why you see a few exception instances in your memory dump.
The latest preview (.NET 9 preview 4) brought another caching structure to the .NET world - so let's order some things here.
Http files are nice and handy - but they are also a bit of a pain to update. So why not generate them from a swagger definition?
Since the last blog post a lot has happened and many new features have been added to NCronJob. In this blog post I would like to introduce you to the new features and explain how you can use them.
I am a big fan of Analyzers, and in this blog post, I will showcase some of my favorite ones!
While your software might be the best in the world, it's only as good as the libraries it uses. In this small blog post, we will discover how to check your solution for NuGet vulnerabilities or deprecated packages.
Everyone falls for that and tries to change a list while enumerating it greeted by the System.InvalidOperationException: Collection was modified; enumeration operation may not execute. message. But how does the List know that you changed it? Let's find out.
In this blog post we will discover whether or not the readonly modifier can make your code faster. So without further ado let's get started.
Sometimes, you have multiple async calls to make, and you want to do that asynchronously and get the results afterward. Let's build a fluent API to do that.
Deconstructor are a C# language feature that allows you to define a method that will be called when an object is being split up into its components. While this is straightforward to implement for your own types, it is not possible to add a deconstructor to a 3rd party type - or is it?
Pattern matching is a powerful feature in C#. It allows you to match a value against a pattern and extract information from the value. The compiler does the magic for you - and sometimes it struckles with that.
C# 13 might get a new feature soon that allows ref and unsafe in iterators and async methods.
Hangfire/Quartz or BackgroundService? Why not something in the middle? Did you ask yourself this question from time to time? Do you want to have a full-blown job scheduler with lots of setups, but more than BackgroundService is needed?
Meet: NCronJob!
Next to the big release of .NET 8, we also released the first preview bUnit v2. This release is a major release, with a lot of new features and improvements. In this post, I will highlight some of the most important changes. This includes new features but also some breaking changes.
I recently discovered this small but very useful utility in xUnit: TheoryData<T>.
A few weeks back, I wrote an article "A new lock type in .NET 9" where I showcased the new Lock type. Nothing fancy - well, at least it was more expressive. But now the dotnet team went a step further with this!
Boolean parameters are nice, but it's hard to keep track of what each one does when you have multiple of them. In this blog post, we will see why it's better to avoid multiple boolean parameters and how to refactor them.
After my first LINQ MindMap: Here is an updated version that includes everything up until .NET 9.
In this blog post, a small and (over)simplified infographic on how the Garbage Collector works.
SearchValues, which were introduced with .NET 8 will become an upgrade and becomes more usable! Let's see how.
Even though we are in the alpha of .NET 9 and .NET 8 was released not more than two months ago, the dotnet team does not sleep and pushes new changes! In this blog post, we are checking what new methods were added to everyones favorite: LINQ.
In the old .NET Framework days, you could use the BinaryFormatter class to serialize and deserialize objects. This can be convenient for cloning or storing some session states. As the BinaryFormatter has some serious security concerns, the .NET team marked it as obsolete (as error) in .NET 7 and onwards.
I am not the biggest fan of AutoMapper. It starts with good intentions but often ends up being a big mess. I have seen it used in many projects, and the configuration of the mappings is often scattered all over the place, and or they are huge!
We know the const keyword with strings - but are they really constant after all? Or can we use some tricks to modify them? Let's see.
In this blog post, I showcase a very simple lock-free ring buffer for logging. I'll show why it's useful and how it works.
There is a new sheriff in town when it comes to the lock keyword, And that is the new System.Threading.Lock type that is introduced in .NET 9. And yes, I know - we still need time to digest the big .NET 8 release.
Only one month after the big release of .NET 8, the dotnet team is already working on the next iteration: .NET 9. With that also comes new language features. The first one is about to be merged into the main development branch: Params Collections.
From time to time, it is nice to store complex objects or lists as JSON in the database. With Entity Framework 8, this is now easily possible. But this was possible all along with Entity Framework 7.
This blog post describes my journey writing a new interceptor for .NET 8. This is not meant as a general tutorial, even though I will showcase some of the code samples.
There are many new cool features with .NET 8 and Blazor in particular. In this blog post, I want to highlight a feature that I believe is very useful in the new context Blazor is living.
The latest version of the .NET (version 8) has introduced a "better" way of logging. This new way of logging is more flexible and enhanced than the previous versions. It is about the LoggerMessageAttribute.
LINQ (Language Integrated Query) is a powerful feature of C# that allows you to query data from different data sources. It is a must-have skill for every C# developer. That is why I created: https://linqmarbles.info/
In this article we will create a class, aka a reference type on the stack, and therefore don't use any managed memory!
Let's drop some "useless" knowledge here. Interfaces can have private methods. This comes with the C# 8 feature: "Default interface methods".
Ever wondered how to use TailwindCSS with Blazor? Let's make it work!
Did you ever hear about "Structured Concurrency"? If not, this article is for you. We will discover what it is, why it is useful, and what it could look like in C#.
This blog post is a small collection of questions I asked as a technical interviewer when we had candidates for software developer positions. This might be helpful for you if you are preparing for a job interview.
The new language feature "primary constructor" which will be released with C# 12 / .NET 8 this year (November 2023) allows you to remove some ceremonial code. Let's see how.
In this article, we will build a minimal version of what ASP.NET Core does - yes, you read right. We will create a very simplistic clone of ASP.NET Core to discuss how the whole thing works. Beginning with a simple console application, we will add the necessary components to make it work as a web server. Bonus points for our own middleware pipeline and dependency injection.
List<T> is one of the most versatile collection types in .NET. As it is meant for general-purpose use, it is not optimized for any specific use case. So, if we look closely enough, we will find scenarios where it falls short. One of these scenarios is when you have lots of data. This article will look at precisely this.
Since C# 8, we have nullable reference types. The word sounds odd, given the fact that reference types are always nullable. The idea is that the default is that your reference types have to be properly initialized. Here are my thoughts after a few years of using them.
Events in C# are a powerful mechanism for decoupling components and enabling a publisher/subscriber model. However, they have a significant drawback: the publisher holds a strong reference to the subscriber, and this can cause memory leaks. This article describes a pattern for implementing weak events in C#.
Are these two expressions the same?
public class MyClass
{
public int A { get; } = Random.Shared.Next(1000);
public int B => Random.Shared.Next(1000);
}
Enums are very simple structures, but some functions like Enum.TryParse can have unexpected behavior. In this short blog post, we discover why and what are the alternatives.
With respect to the current topic around Moq, I want to showcase how you can easily roll out your own fakes so that you are not depending on a third party library.¨
The famous Moq library faced some criticism due to the usage of SponsorLink. What is the problem, and what is going on here? And obviously, I will add all the sources to the articles.
The .NET 8 preview 7 will bring another exciting feature some of you probably awaiting for a long time: Keyed services.
Where C# is the most dominant language in the .NET world, other languages are built on top of the Framework that deserves their respective place. F# is strong when it comes down to functional programming! In this blog post, we will leverage the power of F# and C# to showcase where both excel!
With the famous BenchmarkDotNet library you can benchmark a lot - but it doesn't stop with a single .NET version. You can benchmark multiple versions of the same code that targets different runtimes!
Working with databases can sometimes be daunting, mainly when errors occur. These errors or exceptions can be due to many reasons, such as constraint violations, connection issues, or syntax errors. Entity Framework throws a generic DbException or DbUpdateException for most of these database issues. But we cand get more specific exceptions based on the concrete "problem"! That's where EntityFramework.Exceptions comes in.
I was recently tasked to migrate an application with around 150 projects from the "old"It is still supported .NET Framework 4.8 to a recent .NET 6. As the application is still under development and used, the migration should be done step by step over time in iterative steps rather than a big bang refactoring. This blog post will go a bit into more detail about how I approached the situation and what I learned.
This is a highly subjective post, and there are plenty of ways of approaching it - so take it with a grain of salt and mileage may vary.
In this short blog post, I want to showcase three nice tricks you can do with everybody's favorite data type: the dictionary.
It is a versatile data structure, and we can make it even more versatile!
On a recent LinkedIn Post from Saeed Esmaeelinejad, he asked what is the outcome of:
bool flag = SomeMethod();
M(flag ? 1 : 2);
void M(long number) => Console.WriteLine("long");
void M(short number) => Console.WriteLine("short");
What is the outcome?
In almost all of my projects, I only use xUnit, and here is a small love letter. Especially the one fact I do think makes it a good choice!
LINQ is a very powerful tool for querying data. As the majority of functions are built on top of IEnumerable<T> and it, in most cases returns IEnumerable<T> as well, it is very easy to chain multiple functions together. That leaves you with a question: which one should I use, Select.Where or Where.Select?
You may have heard that when you elide the await keyword in a method that returns a Task or Task<T>, you lose the stack trace. Buy why does that happen? Let's find out!
In this blog post, I'll show you the fundamentals of the Mediator pattern and how to implement it in your application from scratch. And yes, we basically implement the famous MediatR library.
A List is one of the most used data types in .NET. You can dynamically add elements without taking care of how that happens. But do you know what is going on under the hood?
There are many different memory types used in modern C# programs. The more common ones are Span<T> and Memory<T>. Occasionally there is also ReadOnlySequence<T>. What do these types do?
With the upcoming release of .NET, the team introduced an abstraction of time itself. That can bring you major benefits especially if you have to test scenarios where time is a crucial part! Until now, you had to create your own wrapper. This, of course, makes integration with 3rd party libraries tricky.
With preview 4 of .NET 8, a new terminal logger was introduced. It basically removes a lot of the noise that the default logger produces. It also adds some nice colors to the output. Let's see how to use it!
The nameof operator is a great way to get the name of a variable, type, or member. With C# 12 it's getting even better. Let's see how.
TryGetNonEnumeratedCount attempts to determine the number of elements in a sequence without forcing an enumeration. It returns true if it could and false if it couldn't. The API was added with .NET 6 - let's have a look at how that thing works.
I did already write about some useful extension methods for Task and ValueTask. Today I want to show you some useful extension methods for IEnumerable.
In this blog post, we will explore some cool things you can do with ValueTuple. Also, a short explanation of what ValueTuple is and how it works.
In Entity Framework 7, the team has added support for ordered indexes to the fluent API. In this blog post we will look at how to use this feature and what it means for your database.
In this blog post, we will have a look at the different log levels and how to control them.
Microsoft's integrated dependency injection (short DI) container is very powerful, but there are also certain pitfalls. In this article, I will show you what some of the pitfalls are and how you can verify them.
In this small blog post, I will show you how to create your own Validation attribute in ASP.NET Core to tailor-made your validation rules.
In this blog post, we will discuss the "Unit of Work" pattern and how it can be used to implement domain events in a DDD application. For that, we will also discuss how we can leverage middleware to implement the "Unit of Work" pattern in a .NET application. A lot of things are going to happen in this blog post, so let's get started.
Let's talk about Contravariance and Covariance in C# using .NET Framework examples!
Contravariance and covariance are essential concepts in C# when dealing with generics, enabling us to have more flexibility when assigning generic types. So let's have examples straight from the framework itself!
Also, we will go a bit deeper and talk what some differences between generic constraints and things like Contravariance are.
As with every .NET release, Microsoft improves the performance of the runtime and guess what: This release is no exception to this. In this blog post, I want to go through some of the improvements made so far (.NET 8 preview 3).
In this short blog post, I will show you 5 useful extensions for Task
Source Generators are more and more an integral part of the .NET ecosystem. But how does that play together with everyone's favorite: Regular Expressions?
In this blog post we will dive in how we can leverage source generators in combination with regular expression to have a debuggable, but also very performant way of executing regular expressions!
In this blog post, we will explore the use of SIMD instructions to speed up LINQ queries. We will use the Vector
In this blog post we will create a ToolTip component in Blazor from scratch. We will use the Blazor WebAssembly template to create a new project. We will then add a ToolTip component to the project and use it in the Index page. We will also add some styling to the ToolTip component.
The advantage over using a library is that we can customize the component to our needs as well as keeping it simple! So let's get started!
Source generators are a powerful feature introduced to C#, allowing developers to generate additional code during the compilation process automatically. They can help reduce boilerplate, improve performance, and simplify your codebase.
This blog post will introduce source generators, discuss how they work, and walk through an example of a source generator for generating build information.
Did you know you can use the 'is not' operator with exception filtering to simplify and improve your error handling in C#?
In this short blog post, I will show you how to use it.
In this blog post, we will discuss how we can "cache" entries from the database. We will talk about why we would do this in the first place and how to achieve that.
Also, we will talk about some implications and what "cache invalidation" is.
Sometimes you have to map an object to another representation in C#. And you think: Why isn't C# duck-typing capable?
You might hear of libraries like AutoMapper that do the tedious work of mapping one object to another with the same structure. This blog post will give a super simple introduction to how those libraries are working internally.
In the end a bit of a subjective topic on whether or not I would use such libraries.
Skip and Take are used for pagination or limit the number of elements returned by a query.
Since C# 8 you can use Take with a Range. Let's see some examples.
In this blog post we will discover how to write your own small task scheduler / job scheduler with cron notation in ASP.NET Core. You might know similar approaches under the name of Quartz or Hangfire.
With the help of BackgroundService we will build our own, lightweight version of it.
In recent months and years, there was a certain hype around benchmarking, also in the .NET community.
This blog post is meant to ground some of the benchmarking topics and put this into relation to other things so you get a better understanding if it's worth the effort.
I will put that simple question in the room: "Is a square a rectangle?" And you might thank: "Well dah, of course!"
But wait for a second and let's check it together. We will use the L in SOLID: The Liskov Substitution principle to check if this relationship makes sense for us!
The Humble Object Pattern is a design pattern to make especially unit testing easier with the goal of separating behaviors that are easy to handle (domain logic) from behaviors that are hard to handle (like external events or dependencies).
So let's have a look at what it is and how you can utilize it.
A bit back on LinkedIn, there was a discussion about read-only collection and immutability where this is not the point I want to discuss now, as I already covered that here: "ReadOnlyCollection is not an immutable collection".
This post is just about the performance of those types compared to our baseline, the good old List<T>. It also explains why we see the results we see.
In this article, we will discuss the testing pyramid - what it is and what are some problems with that.
We will also discuss a different approach: The testing diamond.
Did you ever need git-specific information like the latest tag or the current commit inside your C# code? Or even the semantic version number of your current build=
Well, there is an easy solution involving source generators.
Did you see the following error in recent days in your build-pipeline:
error NETSDK1194: The "--output" option isn't supported when building a solution.
If so - that is not necessarily your fault at all! Microsoft released a new SDK version, which breaks your builds. Let's see why and what we can do to tackle that.
System.Text.Json.JsonSerializer has a weird quirk in regard to performance and memory management. So we will discuss what is "wrong" with this code: JsonSerializer.Serialize(myObject, new JsonSerializerOptions(...));.
Did you ever ask yourself: What is a middleware, and why should I use it?
If so, this blog post is exactly for you. We will see where we could use a middleware and also how we can use the Dependecy Injection container of ASP.NET Core.
Multi-tenancy is a software architecture pattern where a single instance of a software application is used by multiple customers, with each customer having separate and isolated data, configurations, and resources. RavenDB is a NoSQL document database that provides a flexible and scalable solution for multi-tenant applications. This blog post will explore why multi-tenancy exists, the advantages of using RavenDB for multi-tenant applications, and provide code examples to get you started.
In this blog post, we'll dive into the ins and outs of the repository pattern and examine both its benefits and its potential drawbacks. We will start from the very basic to some more advanced use cases. So let's dive right into it.
Did you ever hear the word "compiler magic" or "syntactic sugar"? Probably yes and therefore we want to dissect what this "magic" really is!
We can see how we can predict performance or bugs by "lowering" our code. Also we will see how things like foreach, var, lock, using, async, await, yield, anonymous types, record, stackalloc, pattern matching, Blazor components, deconstructor, extension methods... do not really exist.
... if you need more than 3 levels of indentation, you're screwed anyway, and should fix your program.
This is written in the Linux style guide. Let's see why they have that rule and how we can overcome deeply nested code.
Another new C# 12 feature might drop soon and makes its debut with the next iteration: Primary Constructors.
The blog post will talk about what a Primary constructor is, why we already have it, and what the proposal tries to change. Exciting times are ahead of us!
Cohesion represents the degree to which the elements of a module belong together. A module or class is said to be highly cohesive if its methods and data are highly related, meaning that a change in one affects just a small number of elements.
We can use this metric to know whether or not an object is in a good shape or needs some refactoring.
Pagination is the process of dividing a set into discrete pages. In the context of Entity Framework, that means we are only getting a certain amount of entries from the database.
And we will implement a very easy solution to make that happen in 3 steps. The result will look like this:
var pagedList = DbContext.BlogPosts.ToPagedList(page: 1, pageSize: 5);
I often read that Task is used for multithreading in C# / .NET, but that is not the case. And it is crucial to understand why this isn't the case. We will also see which problem exactly Task is solving in the first place.
I want to showcase two of my many side projects. My .NET Tips and Tricks website, where I collect and categorize, well, tips and tricks around .NET-related topics as well as my ValueStringBuilder.
Strings are one of the most universal data types. We use them for URLs or regular expressions or even to define some date. With .NET 7 we have a new way of giving those strings a bit of meaning. Meet StringSyntaxAttribute.
I also show you a way how to use them in .NET 6 and earlier.
There is still a long road ahead of us until the release of .NET 8, but the first new language constructs are getting public. The first one I want to present is: Default Parameters in Lambdas.
Many know that you can take ReadOnlySpan<char> objects when dealing with strings. They give you a direct way of operating on the underlying memory. Often times you can use them interchangeably, but there are scenarios where you really have to watch out what is going on.
This blog post will have a look at a major problem with ReadOnlySpan when used like a "regular" string.
Does your Dependency Injection container is one big pile of method calls one after the other?
Are there 50 lines of just AddScoped, AddTransient, and so on? Well, let's fix this.
We can utilize extension methods to make an order to that mess!
.NET knows a big list of collection-like types like: IEnumerable, IQueryable, IList, ICollection, Array, ISet, ImmutableArray, ReadOnlyCollection, ReadOnlyList, and many more.
This blog post will give you an exhaustive list of types in .NET and when to use what.
This blog post will show you a very simple Dependency Injection container.
This will give a better understanding of what Dependency Injection is and how it is done. And sure we will see how this is related to IoC - Inversion of Control.
Sometimes you have an Id of an object and want to delete the underlying thing from the database. But it doesn't make sense to load the whole object from the database to memory first. So how can we achieve this quickly?
ChatGPT is going viral right now. Besides funny conversations, you can use that tool to generate also code for you. But does it really hold up to its reputation and it is a serious pairing partner? Let's see.
In the past, it was tricky to get if the current process runs under elevated rights. In the sense of it is run under the sudo group in *nix (Unix, Linux, macOS, you name it) or administrative rights in Windows.
But that changes with .NET 8 as we now have a unified API for that.
Abstraction and Encapsulation are two fundamental concepts in object-oriented programming. So let us have a small look what the difference is between those two.
Did you ever wonder how we can iterate through a StringBuilder? I mean, of course, we can just call ToString and use the returned string, but that means we materialize the whole thing without good reason.
We can also use a normal for-loop. But we can also find a completely different and probably dumber way! And if you wonder: No, this is not something you do in your daily life, but by doing so, I can show some cool stuff C# and .NET offer.
Do you remember how .NET 6 introduced the ArgumentNullException.ThrowIfNull guard? And afterward, with .NET 7 we've got this excellent bit: ArgumentException.ThrowIfNullOrEmpty? Guess what, there might come some new handy additions for the upcoming .NET 8 iteration.
So let's see what are those new changes and how they make the code simpler.
Analyzers did become an integral part of the .NET ecosystem. Their main responsibility is to find potential code issues and warn you. Often times this comes even with potential fixes you can directly apply.
And Microsoft will continue this journey with the upcoming .NET 8 release. This blog post will show you potential candidates, which will make the cut.
.NET 7 was freshly released but Microsoft does not sleep. .NET 8 is already in the making and I want to showcase to you one new area where the dotnet team is working on Frozen collections.
So let's have a look at what frozen collections are and how they are working.
Use always a
StringBuilder
That is what you can read from time to time. The basic idea is, that a StringBuilder is "better" to be defined.
Why are people telling that lie? Let's discuss this and see what it isn't true.
Often times we hear about allocations on the heap. How can we easily measure this? This article will show you a very easy way of doing so.
Plus we will answer the question how big is an empty array? And if you think 0 bytes, then spoiler alert, that is not the case at all.
Often times we have unit or integration tests that rely on some input data. The easiest solution is just to take some hard-coded values and move on with life. This has some major downsides:
Giving specific values in a test carries meaning, but we are often times not interested in that. We just need to pass the object around to fulfill the API. Also the simplest solution to fulfill your test is literally checking against those values.
Here is an elegant solution to that problem: AutoFixture. I will show you what it can do, especially in combination with xUnit.
You might have heard that mutable value types are evil. But why is that and why does the .NET framework use them then? Are they really that evil?
Let's have a look at a few examples and have a look what is going on!
Often times your API in your program or library evolves. So you will need a mechanism of telling that a specific API (an interface or just a simple method call) is obsolete and might be not there anymore in the next major version.
Also it can happen that you have a preview version of a API, which might not be rock-stable and the API-surface might change. How do we indicate that to the user?
This edition has the following infographics:
DebuggerDisplayAttributeExceptionDispatchInfoimplicit and explicit operator
.NET knows local functions and lambda expressions. You can almost take them interchangeably, but there are also some differences between them.
This article will show the differences between them.
You might have read, that re-throwing an exception like this: throw exc; is considered bad practice and you should just do this: throw; instead.
But why is it like that?
In this article we will have a closer look at LiteDB, a .NET NoSQL Document Store in a single data file. We will discover the advantages of LiteDB and why it is a viable candidate for your next project.
We will also explore what are the differences between a NoSQL and a classical SQL database are and what this has to do with the reminiscent SQL CE or the more modern SQLite database.
In this short blog post I want to show you two silly things so that you can apply right now! Both of them equally silly, but that is not the point (is it ever?).
We will see how to await an integer or TimeSpan and how to foreach through an integer. All of this thanks to the magic of extensions methods.
This edition has the following infographics:
ConfigureAwait on IAsyncDisposableforeachstructnull for a Task
This article will show you what exactly a WebApplicationFactory is and why it is so "mighty" when it comes down to testing. I will highlight some of the properties, which you can leverage to write powerful tests.
Sometimes I publish parts of my infographics I publish on various channels with more explanation.
And then sometimes I don't. This time I just put some of my (hopefully self-explanatory) infographics here.
In this article I will show you what is the difference between x86 (32-bit) vs x64 (64-bit) in the .NET World.
What is the impact if you choose on or another.
Pattern matching, which was introduced in C# 9, is a hell of a beast and does more than you might think.
In this small blog post I show you where the magic is and what it does under the hood.
Did you ever wonder what is a nice way of structuring your Blazor application?
I will show you how I structure my Blazor projects (as well as this very blog). What are the upside in contrast to the "default" structuring you get with the Blazor template.
This is a small story about how memory operates in your .NET application. Well not only .NET but how memory does or does not get allocated.
We will see how a 1 Gigabyte big array is only a few megabytes big to some extend. Furthermore I will discuss working set and committed memory.
NDepend is a static analysis tool for .NET managed code. The tool proposes a large number features, from dependency visualization to Quality Gates and Smart Technical Debt Estimation. For that reasons the community refers to it as the "Swiss Army Knife" for .NET Developers.
So let's check if that descriptionI shamelessly stole from Wikipedia checks out and what we can do with that tool.
Often times it is easier to have a nice illustration at hand, which explains you things the easy way. So let's do this for a lot of LINQ operations like Where, Select and friends.
Of course a small explanation will be attached as well.
You might have code where an object offers you an event to notify you when a specific operation is done. But event's can be tricky to use, especially when you want to have a continuous flow in your application.
That is where TaskCompletionSource comes into play. We can "transform" an event based function into something which is await-able from the outside world via the await keyword.
When you get started or even if you have quite some knowledge it can be confusing to juggle with those terms. So what is the difference between C# and .NET? And what does it have to do with IL and JIT?
C# offers a lot of utility especially around the delegate topic. So let's see what exactly a delegate is and how the distinct types like delegate, Action, Func, Predicate, anonymous function, lambda expressions and MulticastDelegate behave. A lot to digest and discover so let's go.
I already made a post about how the Garbage Collector works in .NET and also introduced the topic of Generation slightly. This article will look a bit more in detail into why we have those mechanisms in the first place, including the Large Object Heap.
Just imagine a car pool: There is a dealer which bought the car and lent's it to you. After a while you will return this car where you got it from. Much like that works an ObjectPool in C#. You can rent an expensive object from the pool and when you are done with it, you just return it. Sounds beautiful, doesn't it?
Let's explore the advantages and disadvantages of a ObjectPools and how they work.
RavenDB is a well known open-source document-oriented databse for .NET. And of course we want to test our logic and not only locally while developing, but also our continuous integration pipeline should be able to run our tests. So let's tackle exactly that.
This article will talk about the garbage collector in .NET. Why do we have and need him? And why it is essential to understand the behavior to know what impact on our application he has.
What is Tail-Recursion? We will discover this "special" form of recursion on the example of the Fibonacci series. Also we will check how much faster it is and why.
In C# we can add the sealed modifier to a class to indicate that no one is allowed to derive / inherit from that class.
Let's have a look at the compiler in certain scenarios what happens if you seal a class.
When we are passing objects around we can do this either via reference or by value. Which of those two methods is faster?
To answer this question we have to dive into a bit of info about what happens exactly when you pass something around and how the other side will receive this.
Besides the big announcements of .NET 6 there are also some smaller features. I want to show case a special one: static abstract interfaces. With this you have ability to extend the contract in that sense, that an implementing class has to provide also static methods. This feature is right now flagged as preview, but you can use it if you want.
This also enables generic math operations on an interface level.
.NET brings two types which seem very similiar
IEnumerableIQueryableWhat is the difference? Most are familiar with using IQueryable when we want to go to the database and back. But why not using IEnumerable?