When you use generic types in C#, it is sometimes hard to understand what the generic argument can represent. For example, what do the strings represent in Dictionary<string, string>? To make the code clearer, you can use type aliases. // ❌ What does the string means? _ = new Dictionary<string, string>(); // Create aliases using UserId = string; using ProjectId = string; // Use the type aliases // ✅ It's… [read more]

In an older post, I wrote about how to compute code coverage for a .NET Core project with Coverlet. In this post, I'll show you how to get code coverage without any additional dependency. Indeed, the .NET SDK 8 now includes all you need to compute code coverage. Microsoft also provides a .NET tool to process the coverage files. Let's start by creating a new xUnit project and removing the dependency on… [read more]

Ico files are old but still widely used. One specificity of the ico format is that it can contain multiple images of different sizes. The format is not very complicated but there are not a lot of free tools to create an ico file from a list of images. Let's create one in .NET! The specification of the ico format is available on Wikipedia. The following code is a simple implementation of the specification.… [read more]

It is often useful to validate JSON documents against a JSON schema. For example, you may want to validate the JSON document that you receive from a REST API or a configuration file written by a user. In this post, I describe how to validate JSON data against a JSON schema in .NET. Using PowerShell, you can use the Test-Json cmdlet to validate JSON data against a JSON schema. .NET doesn't support JSON… [read more]

This post is an update of the original post to take advantage of new .NET 8 features. It is inspired by the following pull request in dotnet/aspire When you display DateTime data to a user, you may want to convert the value to the user's time zone. With server-side Blazor, the code is executed on the server, so DateTime.Now corresponds to the time zone of the server instead of the user's time zone. At the… [read more]

The OpenAPI specification is a powerful tool to describe and document APIs. It is a standard that allows you to define the structure of your API, including the endpoints, the request and response models, and the security requirements. The OpenAPI specification is a JSON or YAML file that can be used to generate documentation, client libraries, and server stubs. Most .NET developers generate the… [read more]

Microsoft Edge can be configured using the setting pages edge://settings. However, some settings are not available in the UI. For instance, you cannot replace the new tab page. You can only configure the content of the page... So, you have to stick with the Edge-like page with news and other stuff you don't care about. Hopefully, you can configure Microsoft Edge using policies. There are multiple ways to… [read more]

In .NET, optional parameters are not always the last parameters. While C# does not allow the declaration of optional parameters in the middle of the parameter list, it is possible to do so in IL or from other languages like VB.NET or F#. Also, the compiler may lower some features and create methods with optional parameters in the middle of the parameter list. Why does it matter? If you write a source… [read more]

If you need to enable AutoLogin in Windows, you can use the registry. However, the password is stored in clear text. It's not a good idea to store a password in clear text. Instead, you can use the LSA to encrypt the password. Note that this is what SysInternals Autologon does. Also, note that the password is not encrypted using the user password. It's encrypted using a key stored in the LSA, and all… [read more]

In C# you can write async code that looks like synchronous code. People using async/await expect to be able to catch specific exception types as synchronous code. This is very convenient, but sometimes you want to get all exceptions thrown from an async method. try { // This will throw multiple exception await Parallel.ForEachAsync(Enumerable.Range(1, 10), async (i, _) => { throw new… [read more]