关于利用DLL,在VB和VC之间数据通信的问题
我做了个DLL,在VB当中调用,现在想通过参数(lpResult)把结果传回VB,但是却不行。各位老大帮我看看,谢了!
extern "C" _declspec(dllexport) int Check_Bank(LPTSTR lpBankCD, LPTSTR lpResult)
{
try{
LPTSTR sRetOK = "BankCD Exist";
LPTSTR sRetFail = "BankCD didn't Exist";
LPTSTR lpSql;
ODynaset oDyna;
lpSql = "select bank_cd from bank where bank_cd='0001'";
oDyna.Open(datab,lpSql);
if(oDyna.IsEOF())
{
SysReAllocStringLen((BSTR*)lpResult,(BSTR)sRetFail,strlen(sRetFail));
return 0;
}else
{
SysReAllocStringLen((BSTR*)lpResult,(BSTR)sRetOK,strlen(sRetOK));
return -1;
}
}catch(...)
{
return 0;
}
}