给WINCC5.1添加报警声音，刚接触这个不太懂，从网上找到了一段代码
#include "apdefap.h"
int gscAction( void )
{
MSG_RTDATA_STRUCT mRT;
int i;
char* pszToken;
//Now is my code
#pragma code("Winmm.dll")
BOOL WINAPI sndPlaySoundA(char* szWave,DWORD dwFlag);
#pragma code()
DWORD SND_ASYNC=0x0001;
DWORD SND_LOOP=0x0008;
DWORD alarmsum,alarmunack;
LPCMN_ERROR errorunack,errorsum;
#pragma code("msrtcli.dll")
#pragma code()
LPDWORD lpdwServiceID;

MSG_SERVICE_NOTIFY_PROC lpfnNotifyProc;

LPMSG_FILTER_STRUCT lpMsgFilter;

DWORD dwNotifyMask;

LPVOID lpvUser;

LPCMN_ERROR lpError;

BOOL n1;

n1=MSRTGetMsgQuit(&alarmunack,errorunack);

SetTagDWord("number",alarmunack);

MSRTGetMsgActual(&alarmsum,errorsum);

SetTagDWord("sum",alarmsum);

if (alarmsum==0)

sndPlaySoundA(NULL,SND_ASYNC);

else

{

if (alarmunack>0)

sndPlaySoundA("C:Program FilesWindows NTPinballSOUND36.WAV",SND_ASYNCSND_LOOP);

else

sndPlaySoundA(NULL,SND_ASYNC);

}
return 1;
}
这段代码在有从首个报警就会报警，可是声音在报警消除后还是不停的响，怎么都处理不了，还有哪位能帮帮忙解释下上面那段代码，中间有很多的声明的变量搞不清楚，谢谢了，
我想做的就是在有报警时，报警的声音会响，没有了声音就自动关闭了。
请各位指点！谢谢了