public static extern int QuerySMStatusA(
uint SM_ID,
char OrgTON,
char OrgNPI,
string OrgAddr,
char[] DestTON,
char[] DestNPI,
string DestAddr,
string Final_date,
out  uint   SM_Status,
out uint  Error_Code);
......
char[]  DestTON={'0'};
char[] DestNPI={'0'};
string Final_date="";
string DestAddr="";
uint Sm_Status,Error_Code;

int i=QuerySMStatusA(sm_id,'2','1',"999999",DestTON,DestNPI, DestAddr,Final_date,out  Sm_Status, out Error_Code);

i,SM_Status,Error_Code 能返回正确的值.