CSharp-Coder

Learn C# exception handling best practices: custom exceptions, global handlers with IExceptionHandler, and structured logging in .NET. Read the guide now! C# exception handling is one of the first things you learn in .NET and one of the last things you master. Most developers can write a try-catch block. Fewer can build a system where errors are caught in the right place, logged with enough context to fix them, and shown to users as safe, consistent responses. In this guide we cover C# exception handling best practices for .NET 8, 9 and 10: when to throw, when to catch, how to design custom exceptions, how to set up a global exception handler in ASP.NET Core, and how to log exceptions so they help you in production. Whether you're a beginner looking up "try catch C#" or a senior engineer standardizing error handling across microservices, you'll find runnable code and the reasoning behind each recommendation. What Is Exception Handling in C#? An exception ...

Learn dependency injection in C# from scratch. Build loosely coupled, testable .NET code with runnable examples, service lifetimes and best practices. Start now! If you've opened an ASP.NET Core project, you've already used dependency injection in C# , even if you didn't know it. Controllers get services "for free," ILogger<T> just shows up, and Program.cs is full of AddScoped and AddSingleton calls. Many developers copy these lines without knowing why they work. In this tutorial we build dependency injection from scratch. We start with tightly coupled code, fix it by hand, write a small IoC container of our own, and then move to the built-in Microsoft.Extensions.DependencyInjection container. By the end you'll know how DI works, when to use each service lifetime, and how it makes your code much easier to unit test. What Is Dependency Injection in C#? Dependency injection (DI) is a design pattern. A class receives the objects it depends on...

Learn SOLID principles in C# with real-world code examples. Master SRP, OCP, LSP, ISP and DIP in .NET — read the guide and write cleaner code today. If you have been writing C# for a while, you have probably opened a class with 2,000 lines, 40 dependencies, and a comment that says "don't touch this" . SOLID principles in C# are the best-known way to stop code from getting like that. This guide covers all five principles (Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion) with real-world C# code examples you can run in a modern .NET project. It also explains why each principle matters and where developers usually go wrong. If you are a beginner learning object-oriented design, an intermediate developer looking for best practices, or a senior engineer getting ready for design interviews, this complete guide to SOLID principles will help you write C# code that is easier to test, extend, and maintain. What Are S...

Learn ASP.NET Core SignalR step by step: build real-time chat and live notifications in C# with hubs, groups, auth, and scaling. Start coding today! Users expect apps to update on their own. A chat message should show up as soon as it is sent. An order status should change without a page refresh. If your app still polls the server every five seconds, you are wasting bandwidth and your users can feel the delay. ASP.NET Core SignalR is Microsoft's built-in library for real-time web features in C#. It lets the server push data to connected clients as soon as something happens. In this SignalR tutorial you will build two common real-time features: a multi-room chat application and user-targeted live notifications . The examples use .NET 10 and cover strongly typed hubs, groups, authentication, sending messages from background services, and scaling out. Along the way we explain why each piece works the way it does, so you can avoid the mistakes that tend to show up in production....

Learn OpenTelemetry .NET step by step: set up distributed tracing, metrics, and logs in ASP.NET Core with runnable C# examples. Start tracing today! A single request in a modern .NET app can pass through an API gateway, three microservices, a message queue, and a database before it returns. When that request becomes slow or fails, log files alone rarely tell you why. OpenTelemetry .NET fixes this. It gives you one vendor-neutral way to collect distributed traces , metrics , and logs from your C# applications. It works with any backend, including Jaeger, Grafana, Prometheus, Azure Monitor, Datadog, Honeycomb, and the .NET Aspire dashboard. This guide covers OpenTelemetry in ASP.NET Core from scratch. You'll learn how distributed tracing works, how to add custom spans and metrics, how to carry trace context through message queues, and which best practices matter in production. It also explains why each piece exists, so you can make good decisions in your own systems. What Is...