vcvars32.bat

 lib /def:yourfile.def /out:yourfile.lib

lib /def:yourfile.def /machine:x64 /out:yourfile64.lib

implib.exe /s mydll.lib mydll.dll

// Function declaration
__declspec(dllexport) void  foo(void);

// Function definition
#include <A.h>
void foo(void) {
; // definition
}

// Load time dynamic linking:
// Application should include X.lib (not X.dll) in the project setting
 #include <A.h>
 int main() {
 foo();
 return 0;
}