What are the meanings of C ++ callback and winapi Macros?

During programming, you may see two macros, callback and winapi, In the function declaration or definition. They are also synonymous with _ stdcall. Check the content in windef. h:

# Define callback _ stdcall

# Define winapi _ stdcall

_ Stdcall is the call type. The call types include __fastcall, _ cdecl, and _ stdcall.

1. _ cdecl call Type: this is the c call rule. This is the default call rule for all functions that are not c ++ member functions or functions that are not labeled _ stdcall or _ fastcall.

2. _ fastcall: this is a fast call. Because the CPU registers are used to store the first few parameters in the function parameter list.

3. _ stdcall call type: The call only uses the stack to push and pop parameters.