Visual Studio 2017中uint8_t标识符未定义问题求助

Hey there, let's walk through the most common reasons you might be hitting this error and how to fix them—these are issues I’ve helped debug for other devs too:

• Old C language standard setting
  stdint.h was introduced in the C99 standard, but VS2017 defaults to the older C89 standard for C projects. To fix this:

  1. Right-click your project → Properties
  2. Navigate to Configuration Properties > C/C++ > Language
  3. Set C Language Standard to ISO C99 Standard (/std:c99) or a newer version.
     For C++ projects, ensure you’re using at least C++11 (VS2017 supports this by default, but double-check the setting just in case).

• Macro conflicts or conditional compilation blocking stdint.h
  Sometimes macros can prevent stdint.h from defining the types you need:

  • Make sure you haven’t defined any macros like uint8_t yourself elsewhere in your code.
  • Check if stdint.h is wrapped in conditional blocks (e.g., #ifdef SOME_FLAG #include <stdint.h> #endif) that aren’t being triggered.
  • Try adding #define __STDC_LIMIT_MACROS before including stdint.h—this ensures the standard integer type definitions are enabled.

• Missing or corrupted VS2017 components
  If your Visual Studio installation is missing key components, the system stdint.h might be incomplete or missing:

  1. Open the Visual Studio Installer
  2. Select your VS2017 installation and click Modify
  3. Ensure the Desktop development with C++ workload is checked, along with a compatible Windows SDK version (e.g., 10.0.17763.0 or newer for VS2017)
  4. Click Modify to install any missing components.

• Incorrect include path or custom stdint.h overriding the system one
  If your project has a custom stdint.h file (in your project directory or an included path), it might be replacing the system’s version which defines uint8_t:

  • Always use #include <stdint.h> (angle brackets) instead of "stdint.h" to prioritize the system header.
  • Check your project’s Properties > Configuration Properties > C/C++ > General > Additional Include Directories for any paths that might contain a conflicting stdint.h, and adjust their order or remove them if needed.

• Precompiled header issues
  If your project uses precompiled headers (like stdafx.h):

  • Make sure stdint.h is included inside the precompiled header, or after the precompiled header is included in your source files.
  • Try cleaning your project (right-click → Clean) and then rebuilding it to clear any cached precompiled header data that might be corrupted.

Give these steps a try—most of the time, it’s one of these issues causing the problem. Let me know if you need more specifics on any of these fixes!

内容的提问来源于stack exchange，提问作者Sinem