va_arg, va_end, and va_start 等宏主要是为了方便访问函数参数而做的va_start sets arg_ptr to the first optional argument in the list of arguments passed to the function. The argument arg_ptr must have va_list type. The argument prev_param is the name of the required parameter immediately preceding the first optional argument in the argument list. If prev_param is declared with the register storage class, the macro’s behavior is undefined. va_start must be used before va_arg is used for the first time.
第一个问题: 先看WinMain函数的返回值: If the function succeeds, terminating when it receives a WM_QUIT message, it should return the exit value contained in that message's wParam parameter. If the function terminates before entering the message loop, it should return zero. 在msg的wParam中保存了退出值
先看WinMain函数的返回值:
If the function succeeds, terminating when it receives a WM_QUIT message, it should return the exit value contained in that message's wParam parameter. If the function terminates before entering the message loop, it should return zero. 在msg的wParam中保存了退出值
[email protected]
[email protected]