十万个为什么 [串口] Windows 串口读写

#include <Windows.h>

#include <stdint.h>
#include <stdio.h>

// ---------------------------------------------------------------------------
class serial_t
{
public:
	~serial_t() { close(); }

	bool is_open() { return m_handle != INVALID_HANDLE_VALUE; }

public:
	void open(uint8_t index, uint32_t baud);

	void close();

	void change_baud(uint32_t baud);

	int read(uint8_t* buffer, int buffer_size);

	int write(uint8_t* buffer, int tx_size);

private:
	// 句柄
	HANDLE m_handle{INVALID_HANDLE_VALUE};

	// 上次打开的序号
	uint8_t m_last_index{0xFF};

	// 上次的波特率
	uint32_t m_last_baud{0};
};

// ---------------------------------------------------------------------------
void serial_t::open(uint8_t index, uint32_t baud)
{
	// 已经打开
	if (is_open() && m_last_index == index)
	{
		// 更换了波特率, 设置波特率
		if (baud != 0 && m_last_baud != baud)
		{
			change_baud(baud);
		}

		return;
	}

	// 关闭之前
	if (is_open())
	{
		close();
	}

	// 路径
	char path[MAX_PATH];
	snprintf(path, MAX_PATH, "\\\\.\\\\COM%d", index);

	// 打开新的
	m_handle = CreateFile(path, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
	if (is_open() == false)
	{
		return;
	}

	// 记录打开
	m_last_index = index;

	// 设置(PS:不知道设置的是什么)
	SetCommMask(m_handle, EV_RXCHAR | EV_TXEMPTY | EV_ERR);
	PurgeComm(m_handle, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);

	// 读写阻塞的时间
	COMMTIMEOUTS time_out = {0};
	time_out.ReadIntervalTimeout = 100; 	// 100ms
	SetCommTimeouts(m_handle, &time_out);

	// 设置波特率
	change_baud(baud);
}


// ---------------------------------------------------------------------------
void serial_t::close()
{
	if (m_handle != INVALID_HANDLE_VALUE)
	{
		PurgeComm(m_handle, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);
		CloseHandle(m_handle);
		m_handle = INVALID_HANDLE_VALUE;
		m_last_index = 0xFF;
		m_last_baud = 0;
	}
}


// ---------------------------------------------------------------------------
void serial_t::change_baud(uint32_t baud)
{
	if (!is_open() || baud == 0 || m_last_baud == baud)
	{
		return;
	}

	m_last_baud = baud;

	DCB dcb = {0};
	dcb.DCBlength = sizeof(DCB);
	GetCommState(m_handle, &dcb);

	dcb.fBinary 	= TRUE;
	dcb.fParity 	= FALSE;
	dcb.BaudRate 	= baud;
	dcb.ByteSize 	= 8;
	dcb.Parity 		= NOPARITY;
	dcb.StopBits 	= ONESTOPBIT;
	dcb.fDtrControl = DTR_CONTROL_DISABLE;
	dcb.fRtsControl = RTS_CONTROL_ENABLE;
	dcb.fOutxCtsFlow = 0;
	dcb.fOutxDsrFlow = 0;
	SetCommState(m_handle, &dcb);
}

// ---------------------------------------------------------------------------
int serial_t::read(uint8_t* buffer, int buffer_size)
{
	if (is_open())
	{

	}
	return 0;
}

// ---------------------------------------------------------------------------
int serial_t::write(uint8_t* buffer, int tx_size)
{
	if (is_open())
	{

	}
	return 0;
}

// ---------------------------------------------------------------------------
int main()
{
}