串口通讯初始化问题

[xbkkl001]

m_hCom = CreateFile(m_com,GENERIC_READ|GENERIC_WRITE,0,0,OPEN_EXISTING,0,NULL);
DCB dcb;

dcb.DCBlength = sizeof(DCB);
if(!GetCommState(m_hCom, &dcb))
{
MessageBox("GetCommState error");
return false;
}
dcb.Parity = NOPARITY;
dcb.BaudRate = CBR_4800;
dcb.ByteSize = 8;
dcb.StopBits = 1;

if(!SetCommState(m_hCom, &dcb))
{
MessageBox("SetCommState error");
return false;
}
程序运行后,到 SetCommState(m_hCom, &dcb)时，返回值为0，出现“SetCommState error”，请问这是为什么，我的DCB设置有问题吗？，请帮我解答一下

[esprite2000]

ZeroMemory( &m_dcb, sizeof( DCB ) );
试试

[esprite2000]

ZeroMemory( &dcb, sizeof( DCB ) );