How to call C++ function in C#

#include "stdafx.h"
#include "QueryAPI.h"

extern "C"
{
__declspec(dllexport) unsigned long QueryUser(const wchar_t* AccountName,
wchar_t* FullUserName,
wchar_t* EmailAddress,
double* Salary,
wchar_t* CardId,
int* Old,
bool* Single)
{
cout<<*AccountName; char* name = "微软" ; ::memcpy((void*)FullUserName,name,100); char* Email = "guochao6398@126.com";
::memcpy((void*)EmailAddress,Email,100);
char* CardID = "12345678";
::memcpy((void*)CardId,CardID,20);
*Salary = 200.34;
//*CardId = "123456789";
*Old = 2;
*Single = false;
return 0;
}
}