项目编译报出如下错误:

Pcre.obj:error LNK2001:无法解析的外部符号 __imp__pcre_freePcre.obj:error LNK2001:无法解析的外部符号 __imp__pcre_compilePcre.obj:error LNK2001:无法解析的外部符号 __imp__pcre_exec

解决办法是在头文件的最开头加上宏定义#define PCRE_STATIC

疑问:为什么必须在其他#include之前呢？

请看pcre.h中48-66行

/* When an application links to a PCRE DLL in Windows, the symbols that areimported have to be identified as such. When building PCRE, the appropriateexport setting is defined in pcre_internal.h, which includes this file. So wedon't change existing definitions of PCRE_EXP_DECL and PCRECPP_EXP_DECL. */#if defined(_WIN32) && !defined(PCRE_STATIC)#  ifndef PCRE_EXP_DECL#    define PCRE_EXP_DECL  extern __declspec(dllimport)#  endif#  ifdef __cplusplus#    ifndef PCRECPP_EXP_DECL#      define PCRECPP_EXP_DECL  extern __declspec(dllimport)#    endif#    ifndef PCRECPP_EXP_DEFN#      define PCRECPP_EXP_DEFN  __declspec(dllimport)#    endif#  endif#endif

参考:

Google it , I found the thread about the error, a comment gives the solutions:Building under Windows:If you want to statically link this program against a non-dll .a file, you mustdefine PCRE_STATIC before including pcre.h, otherwise the pcre_malloc() andpcre_free() exported functions will be declared __declspec(dllimport), withunwanted results. So in this environment, uncomment the following line. *///#define PCRE_STATIC

参考链接: