✉️ ProudCloud Weekly #5

When C# needs low level interactions, P/Invoke saves the day

If you’ve ever hit the limits of what the .NET framework or .NET libraries provide out of the box, Platform Invocation Services (P/Invoke) is your bridge to native code.

P/Invoke lets you call unmanaged functions from DLLs (like Windows APIs written in C or C++) directly from your C# code. For example, if you need access to low-level OS features, hardware integration, or performance-optimized native libraries, P/Invoke is how you get there without rewriting everything in C++.

Why should I care? Isn't C# supposed to be a high-level language?

• 🔌 Access to OS features — tap into Windows API calls not exposed in .NET.
• ⚡ Performance gains — leverage optimized native libraries for heavy computations.
• 🛠️ Integration — connect your .NET applications to existing C/C++ codebases.
• 📚 Deeper understanding — learning P/Invoke sharpens your knowledge of memory layout, calling conventions, and interop boundaries.

You don’t need to master it for day-to-day development, but having P/Invoke in your toolbox makes you a stronger, more versatile developer—especially when dealing with legacy systems, specialized APIs, or advanced performance scenarios.

Most developers paint themselves into a corner, staying at the highest level of abstraction. They deprive themselves of the more low-level interactions that set their capabilities apart from other .NET developers. Having a knowledge of this murkier, less 'safe' world can only increase your marketibility as a developer and give you something interesting to show-off in interviews.

Interop isn’t scary — P/Invoke makes it elegant.

Here’s how you can call the classic Windows MessageBox function from C# using P/Invoke:

What’s happening here:

• DllImport tells .NET which DLL contains the function (user32.dll).
• The method signature in C# matches the native one, so .NET can marshal parameters across the managed/unmanaged boundary.
• Running this will pop up a Windows message box — no C++ code required.

Want the video version?

​ Let me show you how it's done In this video, I demonstrate calls using P/Invoke Watch the video →

This video will give you the primer you need to start using P/Invoke. Don't just take my word for it. Check out the comments!

That's it for this issue. I hope you found the content useful. Stay tuned for more updates, and don't forget to stay in touch with me on LinkedIn. My DMs are open.

Keep learning and growing,

Nick Proud ProudCloud.dev ​ Stuff you should deffo check out 😁 Courses crafted for the real world - Dometrain Subscribe on YouTube Connect with me on Linkedin ​

​
​Unsubscribe · Preferences​