📄 rs232.cpp
字号:
////////////////////////////////////////////////////////////////////////////////
//// ////
//// RS232 ////
//// ////
//// Author: MonkeyKing Aug 31th, 2003 ////
//// ////
////////////////////////////////////////////////////////////////////////////////
#include <windows.h>
class RS232 {
public:
RS232( void );
RS232( LPCSTR lpszPortNum );
~RS232();
// For more definitions see <winbase.h>
int open( LPCSTR lpszPortNum = "com1", // 串口号
DWORD dwBaudRate = CBR_9600, // 波特率
BYTE byParity = NOPARITY, // 奇偶校验
BYTE byStopBits = ONESTOPBIT,// 停止位个数
BYTE byByteSize = 8 ); // 字节长度
DWORD output( LPCVOID pdata, DWORD len );
DWORD input( LPVOID pdest, DWORD len, DWORD dwMaxWait = 500 );
LPSTR GetErrorMessage( void );
void close();
private:
VOID ErrorToString( LPCSTR lpszMessage );
BOOL IsNT( void );
TCHAR m_lpszErrorMessage[256];
HANDLE m_hCom; // 串口句柄
OVERLAPPED m_ov; // 包含异步输入输出操作信息的结构
};
////////////////////////////////////////////////////////////////////////////////
//// ////
//// RS232::RS232() ////
//// ////
////////////////////////////////////////////////////////////////////////////////
RS232::RS232( void )
{
m_hCom = 0;
m_lpszErrorMessage[0] = '\0';
ZeroMemory(&m_ov, sizeof(m_ov));
}
RS232::RS232( LPCSTR lpszPortNum )
{
RS232::RS232();
RS232::open( lpszPortNum );
}
////////////////////////////////////////////////////////////////////////////////
//// ////
//// RS232::~RS232() ////
//// ////
////////////////////////////////////////////////////////////////////////////////
RS232::~RS232() {
close();
}
////////////////////////////////////////////////////////////////////////////////
//// ////
//// RS232::GetErrorMessage ////
//// ////
////////////////////////////////////////////////////////////////////////////////
LPSTR RS232::GetErrorMessage( void ) {
return m_lpszErrorMessage;
}
////////////////////////////////////////////////////////////////////////////////
//// ////
//// RS232::open( ) ////
//// ////
////////////////////////////////////////////////////////////////////////////////
int RS232::open( LPCSTR lpszPortNum,
DWORD dwBaudRate,
BYTE byParity,
BYTE byStopBits,
BYTE byByteSize ) {
DCB dcb; //串口设备控制块 Device Control Block
BOOL bSuccess;
// m_hCom即为函数返回的串口的句柄
m_hCom = CreateFile( lpszPortNum, // pointer to name of the file
GENERIC_READ|GENERIC_WRITE, // 允许读写。
0, // 通讯设备必须以独占方式打开。
NULL, // 无安全属性，表示该串口不可
// 被子程序继承。
OPEN_EXISTING, // 通讯设备已存在。
FILE_FLAG_OVERLAPPED, // 使用异步方式 overlapped I/O。
NULL); // 通讯设备不能用模板打开。
if ( m_hCom == INVALID_HANDLE_VALUE ) {
RS232::ErrorToString("RS232::open() CreateFile() failed, invalid handle value");
return FALSE;
}
// 与串口相关的参数非常多，当需要设置串口参数时，通常是先取得串口
// 的参数结构，修改部分参数后再将参数结构写入
bSuccess = GetCommState(m_hCom, &dcb);
if ( !bSuccess ) {
RS232::close();
RS232::ErrorToString("RS232::open() GetCommState() failed");
return FALSE;
}
dcb.BaudRate = dwBaudRate; // 串口波特率。
dcb.Parity = byParity; // 校验方式，值0~4分别对应无校验、奇
// 校验、偶校验、校验、置位、校验清零。
dcb.fParity = 0; // 为1的话激活奇偶校验检查。
dcb.ByteSize = byByteSize; // 一个字节的数据位个数，范围是5~8。
dcb.StopBits = byStopBits; // 停止位个数，0~2分别对应1位、1.5位、
// 2位停止位。
if ( !bSuccess ) {
RS232::close();
RS232::ErrorToString("RS232::open() SetCommState() failed");
return FALSE;
}
return TRUE;
}
////////////////////////////////////////////////////////////////////////////////
//// ////
//// RS232::output() ////
//// ////
////////////////////////////////////////////////////////////////////////////////
DWORD RS232::output( LPCVOID pdata, DWORD len ) {
BOOL bSuccess;
DWORD written = 0;
if ( len < 1 )
return 0;
// create event for overlapped I/O
m_ov.hEvent = CreateEvent( NULL, // pointer to security attributes
FALSE, // flag for manual-reset event
FALSE, // flag for initial state
""); // pointer to event-object name
if ( m_ov.hEvent == INVALID_HANDLE_VALUE ) {
RS232::ErrorToString( "RS232::output() CreateEvent() failed" );
return -1;
}
bSuccess = WriteFile( m_hCom, // handle to file to write to
pdata, // pointer to data to write to file
len, // number of bytes to write
&written, // pointer to number of bytes written
&m_ov ); // pointer to structure needed for overlapped I/O
// 如果函数执行成功的话检查written的值为写入的字节数，WriteFile函数执行完毕后
// 自行填充的，利用此变量的填充值可以用来检查该函数是否将所有的数据成功写入串口
if ( RS232::IsNT() ) {
bSuccess = GetOverlappedResult( m_hCom, &m_ov, &written, TRUE );
if ( !bSuccess ) {
CloseHandle( m_ov.hEvent );
RS232::ErrorToString( "RS232::output() GetOverlappedResult() failed" );
return -1;
}
}
else if ( len != written ) {
CloseHandle( m_ov.hEvent );
RS232::ErrorToString( "RS232::output() WriteFile() failed" );
return -1;
}
CloseHandle( m_ov.hEvent );
return written;
}
////////////////////////////////////////////////////////////////////////////////
//// ////
//// RS232::input() ////
//// ////
////////////////////////////////////////////////////////////////////////////////
DWORD RS232::input( LPVOID pdest, DWORD len, DWORD dwMaxWait ) {
BOOL bSuccess;
DWORD result = 0,
read = 0, // num read bytes
mask = 0; // a 32-bit variable that receives a mask
// indicating the type of event that occurred
if ( len < 1 )
return(0);
// create event for overlapped I/O
m_ov.hEvent = CreateEvent( NULL, // pointer to security attributes
FALSE, // flag for manual-reset event
FALSE, // flag for initial state
"" ); // pointer to event-object name
if ( m_ov.hEvent == INVALID_HANDLE_VALUE ) {
RS232::ErrorToString( "RS232::input() CreateEvent() failed" );
return -1;
}
// Specify here the event to be enabled
bSuccess = SetCommMask( m_hCom, EV_RXCHAR );
if ( ! bSuccess ) {
CloseHandle(m_ov.hEvent);
RS232::ErrorToString("RS232::input() SetCommMask() failed");
return -1;
}
// WaitForSingleObject
bSuccess = WaitCommEvent(m_hCom, &mask, &m_ov);
if ( !bSuccess ) {
int err = GetLastError();
if ( err == ERROR_IO_PENDING ) {
result = WaitForSingleObject(m_ov.hEvent, dwMaxWait); //wait dwMaxWait
// milli seconds before returning
if ( result == WAIT_FAILED ) {
CloseHandle(m_ov.hEvent);
RS232::ErrorToString( "RS232::input() WaitForSingleObject() failed" );
return -1;
}
}
}
// The specified event occured?
if ( mask & EV_RXCHAR )
{
bSuccess = ReadFile( m_hCom, // handle of file to read
pdest, // address of buffer that receives data
len, // number of bytes to read
&read, // address of number of bytes read
&m_ov); // address of structure for data
if ( RS232::IsNT() ) {
bSuccess = GetOverlappedResult(m_hCom, &m_ov, &read, TRUE);
if ( !bSuccess ) {
CloseHandle( m_ov.hEvent );
RS232::ErrorToString( "RS232::input() GetOverlappedResult() failed" );
return -1;
}
}
else if ( !bSuccess ) {
CloseHandle(m_ov.hEvent);
RS232::ErrorToString( "RS232::input() ReadFile() failed" );
return -1;
}
}
else {
CloseHandle(m_ov.hEvent);
wsprintf( m_lpszErrorMessage, "RS232::input() No EV_RXCHAR occured\n" );
return -1;
}
CloseHandle(m_ov.hEvent);
return read;
}
////////////////////////////////////////////////////////////////////////////////
//// ////
//// RS232::Close() ////
//// ////
////////////////////////////////////////////////////////////////////////////////
void RS232::close( void ) {
if ( m_hCom > 0 )
CloseHandle( m_hCom );
m_hCom = 0;
}
////////////////////////////////////////////////////////////////////////////////
//// ////
//// RS232::IsNT ////
//// ////
////////////////////////////////////////////////////////////////////////////////
VOID RS232::ErrorToString( LPCSTR lpszMessage ) {
LPVOID lpMessageBuffer;
DWORD error = GetLastError();
FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM, // source and processing options
NULL, // pointer to message source
error, // requested message identifie
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // the user default language.
( LPTSTR ) &lpMessageBuffer, // pointer to message buffer
0, // maximum size of message buffer
NULL); // address of array of message inserts
// and copy it in our error string
wsprintf(m_lpszErrorMessage,"%s: (%d) %s\n", lpszMessage, error, lpMessageBuffer);
LocalFree(lpMessageBuffer);
}
////////////////////////////////////////////////////////////////////////////////
//// ////
//// RS232::IsNT ////
//// ////
////////////////////////////////////////////////////////////////////////////////
BOOL RS232::IsNT( void ) {
OSVERSIONINFO osvi;
osvi.dwOSVersionInfoSize = sizeof( OSVERSIONINFO );
GetVersionEx( &osvi );
if ( osvi.dwPlatformId == VER_PLATFORM_WIN32_NT )
return TRUE;
else
return FALSE;
}
////////////////////////////////////////////////////////////////////////////////
//// ////
//// The End of RS232 ////
//// ////
////////////////////////////////////////////////////////////////////////////////⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -