Reflection in C#: When and Why You Should (or Shouldn’t) Use It

Thanks to Canva.

Ever stumbled across System.Reflection in C# and thought, Wait, why would I ever need this? Or maybe you've heard someone mutter, Reflection is bad for performance, and you just nodded along like you totally knew what they meant.

Well, let’s clear that up. Reflection is one of those tools that’s insanely powerful when used right and a total footgun when misused.

So, let’s break it down — where it shines, where it burns, and what you can do instead when performance is a concern.

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What is Reflection?

In simple terms, reflection lets your C# code inspect and manipulate itself at runtime. You can dynamically load assemblies, inspect metadata, access private fields, and even invoke methods you didn’t know existed at compile time.

Think of it like this: Imagine your code is a locked safe, and reflection is that shady locksmith who can open any compartment inside — even the ones marked DO NOT TOUCH.

Type type = typeof(MyClass);
MethodInfo method = type.GetMethod("HiddenMethod", BindingFlags.NonPublic | BindingFlags.Instance);
method.Invoke(myClassInstance, null);

Cool, right? But before you go all mad scientist, let’s talk about when you should — and shouldn’t — use it.

When You Should Use Reflection

1. Plugins & Dynamic Loading

Ever built a system where users can drop in their own DLLs, and your app loads them dynamically? Reflection makes that possible. You don’t need to know which classes exist at compile time — you just load them when needed.

Assembly assembly = Assembly.LoadFrom("Plugin.dll");
Type pluginType = assembly.GetType("MyPluginNamespace.PluginClass");
object pluginInstance = Activator.CreateInstance(pluginType);

Where it’s useful:

• Modding support in games
• Custom plugin architectures (think VS Code extensions)
• Enterprise apps where you swap logic dynamically