请问哪位用过winsnmp中的snmplisten函数

if(pSnmp.sessionID==FALSE)
{
pSnmp.CreateSession(CEmulator_MFCDlg::m_hWnd,wMsg);
pSnmp.sessionID=TRUE;
}
if((pSnmp.entity=SnmpStrToEntity(pSnmp.session,"192.168.0.170"))==SNMPAPI_FAILURE)
AfxMessageBox("SendMsg failure--entity");
if(SnmpListen(pSnmp.entity,SNMPAPI_ON )!=SNMPAPI_SUCCESS)
AfxMessageBox("SnmpListen failure--entity");
调试到SnmpListen执行时返回错"An error occurred in the network transport layer while trying to bind a socket for the entity specified by the hEntity parameter."
那位高手能指点一下的