在.h中定义了和main函数中一样的函数,在返回值前面添加修饰关键字inline即可.

.h中的生命和.cpp中的实现

1 #if !defined(AFX_STDAFX_H__CF8E6B35_199B_45D0_9F2A_929A26911DD2__INCLUDED_) 2 #define AFX_STDAFX_H__CF8E6B35_199B_45D0_9F2A_929A26911DD2__INCLUDED_ 3  4 #if _MSC_VER > 1000 5 #pragma once 6 #endif // _MSC_VER > 1000 7  8 #define WIN32_LEAN_AND_MEAN        // Exclude rarely-used stuff from Windows headers 9 10 #include 
     
      11 12 13 inline void Fun();14 15 16 // TODO: reference additional headers your program requires here17 18 //{
    {AFX_INSERT_LOCATION}}19 // Microsoft Visual C++ will insert additional declarations immediately before the previous line.20 21 #endif // !defined(AFX_STDAFX_H__CF8E6B35_199B_45D0_9F2A_929A26911DD2__INCLUDED_)
     

1 #include "stdafx.h" 2 #include 
     
       3  4 // TODO: reference any additional headers you need in STDAFX.H 5 // and not in this file 6  7 inline void Fun() 8 { 9   cout << " .h Fun()" << endl;10 }
     

 

main中的函数inline void Fun();

1 #include "stdafx.h" 2 #include 
     
       3 #include 
      
        4 #include 
       
         5  6  7 // inline void Fun(); 8  9 inline void Fun()10 {11   cout << "Main() Fun()" << endl;12 }13 14 void Fun2(int nData = 2)15 {16   17 }18 19 20 int main(int argc, char* argv[])21 {22 23   void Fun3(int&);24 25   Fun();26   Fun2(3);27 28   int nData = 4;29 30   Fun3(nData);31   32   cout << nData << endl;33   34   return 0;35 }36 37 void Fun3(int& nData )38 {39   nData = 90;40  // cout << nData << endl; 41 }
       
      
     

Fun3(int&);函数调用的时候引用,在函数中更改了数值之后,穿进去的变量的值也会更改.