首次OpenGL开发遇VS Error E1696：无法打开stdafx.h的原因与解决

Hey there, let's work through this E1696 error you're facing in your OpenGL project. I’ve run into this exact issue dozens of times with Visual Studio’s precompiled header (PCH) system, so here’s a clear breakdown of what’s going on and how to fix it:

What’s Causing the Error? #

The core issue boils down to how Visual Studio handles precompiled headers:

• Visual Studio requires every .cpp source file in your project to include stdafx.h as the very first line if precompiled headers are enabled. You’ve added it to main.cpp, but Twitch.cpp (which includes Engine.h) doesn’t have this line. When the compiler processes Engine.h via Twitch.cpp, it can’t find the required stdafx.h because Twitch.cpp didn’t include it first.
• If your project is set to use precompiled headers but some files skip this step, the compiler throws this error to enforce the PCH rules.

Step-by-Step Fixes #

1. Add stdafx.h to All .cpp Files #

The quickest fix is to make sure Twitch.cpp includes stdafx.h as its first line:

#include "stdafx.h"
// Then include other headers like Engine.h
#include "Engine/Engine.h"

// Rest of your Twitch.cpp code...
}

Remember: stdafx.h must be the first include in every .cpp file—Visual Studio skips all code before this line when using precompiled headers.

2. Disable Precompiled Headers (If You Don’t Need Them) #

If you don’t want to use Visual Studio’s precompiled header system at all:

• Right-click your Twitch project in Solution Explorer → Properties
• Navigate to Configuration Properties > C/C++ > Precompiled Headers
• Set the Precompiled Header dropdown to Not Using Precompiled Headers
• Click OK, then clean your project (Build → Clean Solution) and rebuild it.

3. Verify Include Paths (If stdafx.h Is in a Non-Standard Location) #

If stdafx.h isn’t in your project’s root directory, double-check that its folder is in Visual Studio’s include path:

• Right-click your project → Properties > Configuration Properties > C/C++ > General
• Under Additional Include Directories, add the full path to the folder containing stdafx.h (e.g., $(ProjectDir)/Headers if it’s in a Headers subfolder)
• Click OK and rebuild.

4. Optional: Add stdafx.h to Engine.h (Less Preferred) #

While not the most standard approach, you can add #include "stdafx.h" to the very top of Engine.h if it’s included by multiple .cpp files. That said, it’s better practice to let each .cpp file handle the PCH include first, as it keeps your headers cleaner and follows Visual Studio’s intended workflow.

内容的提问来源于stack exchange，提问作者Nitay Derei