C# (pronounced see sharp, like the musical note ) is a general-purpose, multi-paradigm programming language encompassing strong typing, lexically scoped, declarative, imperative, functional, generic, object-oriented, and component-oriented programming disciplines. It was introduced in 2000 by Microsoft as part of its .NET initiative, and later approved as an international standard by Ecma (ECMA-334) and ISO (ISO/IEC 23270:2018).
Unsafe accessors can be used to access private members of a class, just like you would with reflection. And the same can be said about changing the value of a readonly field. Let’s assume the following class: Let’s say that for some reason you want to change the value of that read-only field. You could…
In a previous article we covered how to access private members using UnsafeAccessor. This time around, we want to look at it’s performance compared to Reflection, and to see whether it’s truly zero-overhead or not. We’re going to do four benchmarks. If you want to run the benchmarks yourself, you have the code below: Benchmark…
Starting with C# 12, a new ExperimentalAttribute is introduced allowing you to mark types, methods, properties or assemblies as being experimental features. This will trigger a compiler warning during usage which can be disabled using a #pragma tag. The Experimental attribute requires a diagnosticId parameter to be passed in the constructor. That diagnostic ID will…
The ref readonly modifier enables a more transparent way of passing read-only references to a method. Passing of readonly references was already possible in C# by using the in modifier ever since version 7.2, but that syntax had some limitations, or rather too little constraints. So how does the new modifier work? Let’s assume the…
A NullReferenceException is a common runtime error which occurs when your code tries to access or manipulate an object or a member of an object, but the object reference is currently set to null (meaning it doesn’t reference any valid object in memory). In other words, you’re trying to perform an operation on something that…
Interceptors are an experimental compiler feature introduced in .NET 8, meaning it may change or be removed in a future release of the framework. To see what else is new in .NET 8, check out our What’s new in .NET 8 page. To enable the feature, you’ll need to turn on a feature flag by…
This exception is thrown when you are building an identity DbContext without providing the user and role stores using AddUserStore and AddRoleStore. You can provide both configurations with a single call to AddEntityFrameworkStores like in the example below: The full exception for reference: System.AggregateException: ‘Some services are not able to be constructed (Error while validating…
.NET 8 adds support for serializing properties from interface hierarchies. This means that all the properties from all interfaces in the hierarchy will be included in the serialization. The most important thing is where you start. Let’s take the following hierarchy as an example: Now, during serialization, if you pass along a Derived2Impl instance stored…
Similar to serializing into non-public members, you can deserialize into non-public members by providing a constructor with parameters matching the non-public member names and by annotating the non-public members with the JsonInclude attribute. Let’s jump straight to an example: Note how we haven’t annotated PublicProperty in any way and we haven’t included it in the…
JsonStringEnumConverter is not compatible with native AOT. To fix that, NET 8 introduces a new converter type JsonStringEnumConverter<TEnum> that is compatible with native AOT. To use the new type, simply annotate your types as follows: Keep in mind: enum deserialization is case insensitive, while serialization can be cusomized via JsonNamingPolicy. What happens if you try…
If you’re just getting started with interceptors, you might be getting one of the following errors: Error CS0246 The type or namespace name ‘InterceptsLocationAttribute’ could not be found (are you missing a using directive or an assembly reference?) Error CS0246 The type or namespace name ‘InterceptsLocation’ could not be found (are you missing a using…
Starting with .NET 8 you can mark JsonSerializerOptions instances as read-only, preventing further changes to the instance. To freeze the instance, simply call MakeReadOnly on the options instance. Let’s take an example: Furthermore, you can check if an instance was frozen or not by checking the IsReadOnly property. Attempting to modify a JsonSerializerOptions instance after…