#pragma once
class CComHelper
{
private:
	HANDLE hCom;
public:
	bool Open();
	void Set();
	DWORD Read(char str[], int length);
	bool Write(char* data, int length);
	bool Close();
};

#include "pch.h"
#include "CComHelper.h"

bool CComHelper::Open()
{
    hCom = CreateFile(_T("COM5"), GENERIC_WRITE | GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
	if (hCom==(HANDLE)-1)
	{
		return false;
	}
	return true;

}

void CComHelper::Set()
{
	SetupComm(hCom, 100, 100);
	COMMTIMEOUTS TimeOuts; //设定读超时
	TimeOuts.ReadIntervalTimeout = MAXDWORD;
	TimeOuts.ReadTotalTimeoutMultiplier = 0;
	TimeOuts.ReadTotalTimeoutConstant = 0;

	
	TimeOuts.WriteTotalTimeoutConstant = 500;//设定写超时
	TimeOuts.WriteTotalTimeoutMultiplier = 100;
	SetCommTimeouts(hCom, &TimeOuts);

	DCB dcb;
	GetCommState(hCom, &dcb);
	dcb.BaudRate = 9600; //波特率为9600
	dcb.ByteSize = 8; //每个字节有8位
	dcb.Parity = NOPARITY; //无奇偶校验位
	dcb.StopBits = TWOSTOPBITS; //两个停止位
	SetCommState(hCom, &dcb);
	PurgeComm(hCom, PURGE_TXCLEAR | PURGE_RXCLEAR);
}

DWORD CComHelper::Read(char* data, int length)
{
	
	DWORD dwCount = (DWORD)length;
	bool bReadStat = ReadFile(hCom, data, dwCount, &dwCount, NULL);
	return dwCount;

}

bool CComHelper::Write(char* data, int length)
{
	DWORD dwWrite = (DWORD)length;
	COMSTAT ComStat;
	DWORD  dwError;
	ClearCommError(hCom, &dwError, &ComStat);
	bool bWriteStat = WriteFile(hCom, data, dwWrite, &dwWrite, NULL);
	if (!bWriteStat)
	{
		return false;
	}
	PurgeComm(hCom, PURGE_TXABORT| PURGE_RXABORT|PURGE_TXCLEAR | PURGE_RXCLEAR);
	return true;
}

bool CComHelper::Close()
{
	bool result = CloseHandle(hCom);
	return result;
}

// SerialPortTestDlg.h: 头文件
//

#pragma once
#include "CComHelper.h"


// CSerialPortTestDlg 对话框
class CSerialPortTestDlg : public CDialogEx
{
// 构造
public:
	CSerialPortTestDlg(CWnd* pParent = nullptr);	// 标准构造函数

	CComHelper com;

// 对话框数据
#ifdef AFX_DESIGN_TIME
	enum { IDD = IDD_SERIALPORTTEST_DIALOG };
#endif

	protected:
	virtual void DoDataExchange(CDataExchange* pDX);	// DDX/DDV 支持


// 实现
protected:
	HICON m_hIcon;

	// 生成的消息映射函数
	virtual BOOL OnInitDialog();
	afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
	afx_msg void OnPaint();
	afx_msg HCURSOR OnQueryDragIcon();
	DECLARE_MESSAGE_MAP()
public:
	afx_msg void OnBnClickedBtnInit();
	afx_msg void OnBnClickedBtnOpen();
	afx_msg void OnBnClickedBtnWrite();
	afx_msg void OnBnClickedBtnRead();
};

// SerialPortTestDlg.cpp: 实现文件
//

#include "pch.h"
#include "framework.h"
#include "SerialPortTest.h"
#include "SerialPortTestDlg.h"
#include "afxdialogex.h"
#include "resource.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif


// 用于应用程序“关于”菜单项的 CAboutDlg 对话框

class CAboutDlg : public CDialogEx
{
public:
	CAboutDlg();

// 对话框数据
#ifdef AFX_DESIGN_TIME
	enum { IDD = IDD_ABOUTBOX };
#endif

	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV 支持

// 实现
protected:
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialogEx(IDD_ABOUTBOX)
{
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialogEx::DoDataExchange(pDX);
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialogEx)
END_MESSAGE_MAP()


// CSerialPortTestDlg 对话框



CSerialPortTestDlg::CSerialPortTestDlg(CWnd* pParent /*=nullptr*/)
	: CDialogEx(IDD_SERIALPORTTEST_DIALOG, pParent)
{
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CSerialPortTestDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialogEx::DoDataExchange(pDX);
}

BEGIN_MESSAGE_MAP(CSerialPortTestDlg, CDialogEx)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_BTN_INIT, &CSerialPortTestDlg::OnBnClickedBtnInit)
	ON_BN_CLICKED(IDC_BTN_OPEN, &CSerialPortTestDlg::OnBnClickedBtnOpen)
	ON_BN_CLICKED(IDC_BTN_WRITE, &CSerialPortTestDlg::OnBnClickedBtnWrite)
	ON_BN_CLICKED(IDC_BTN_READ, &CSerialPortTestDlg::OnBnClickedBtnRead)
END_MESSAGE_MAP()


// CSerialPortTestDlg 消息处理程序

BOOL CSerialPortTestDlg::OnInitDialog()
{
	CDialogEx::OnInitDialog();

	// 将“关于...”菜单项添加到系统菜单中。

	// IDM_ABOUTBOX 必须在系统命令范围内。
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != nullptr)
	{
		BOOL bNameValid;
		CString strAboutMenu;
		bNameValid = strAboutMenu.LoadString(IDS_ABOUTBOX);
		ASSERT(bNameValid);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// 设置此对话框的图标。  当应用程序主窗口不是对话框时，框架将自动
	//  执行此操作
	SetIcon(m_hIcon, TRUE);			// 设置大图标
	SetIcon(m_hIcon, FALSE);		// 设置小图标

	// TODO: 在此添加额外的初始化代码

	return TRUE;  // 除非将焦点设置到控件，否则返回 TRUE
}

void CSerialPortTestDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialogEx::OnSysCommand(nID, lParam);
	}
}

// 如果向对话框添加最小化按钮，则需要下面的代码
//  来绘制该图标。  对于使用文档/视图模型的 MFC 应用程序，
//  这将由框架自动完成。

void CSerialPortTestDlg::OnPaint()
{
	if (IsIconic())
	{
		CPaintDC dc(this); // 用于绘制的设备上下文

		SendMessage(WM_ICONERASEBKGND, reinterpret_cast<WPARAM>(dc.GetSafeHdc()), 0);

		// 使图标在工作区矩形中居中
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// 绘制图标
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialogEx::OnPaint();
	}
}

//当用户拖动最小化窗口时系统调用此函数取得光标
//显示。
HCURSOR CSerialPortTestDlg::OnQueryDragIcon()
{
	return static_cast<HCURSOR>(m_hIcon);
}



void CSerialPortTestDlg::OnBnClickedBtnInit()
{
	com.Set();
}


void CSerialPortTestDlg::OnBnClickedBtnOpen()
{
	bool bResult = com.Open();
}


void CSerialPortTestDlg::OnBnClickedBtnWrite()
{
	char buffer[1024];
	CString input;
	GetDlgItemText(IDC_EDIT_WRITE,input);
	char* p = input.GetBuffer(0);
	strcpy_s(buffer, p);
	bool bResult = com.Write(buffer, strlen(p));
}


void CSerialPortTestDlg::OnBnClickedBtnRead()
{
	char buffer[1024];
	DWORD length = com.Read(buffer, 1024);
	CString str = CString(buffer,length);
	SetDlgItemText(IDC_EDIT_READ, str);
}

C++ 串口通信程序

#include "windows.h"
#include <iostream>  
#include <TCHAR.H>   
#include <string.h>

using namespace std;

HANDLE handle_file; //串口句柄

int serial_open(LPCWSTR COMx, int baudrate) 
{
	//打开串口
	handle_file = CreateFile(COMx, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
	if (handle_file == INVALID_HANDLE_VALUE)
	{
		printf("打开串口失败!\n");
		return FALSE;
	}

	//设置读写缓冲区
	SetupComm(handle_file, 1024, 1024); 

	//设置读写超时 
	COMMTIMEOUTS TimeOuts;
	TimeOuts.ReadIntervalTimeout=1000;
	TimeOuts.ReadTotalTimeoutMultiplier=500;
	TimeOuts.ReadTotalTimeoutConstant=5000; 
	TimeOuts.WriteTotalTimeoutMultiplier=500;
	TimeOuts.WriteTotalTimeoutConstant = 2000;
	SetCommTimeouts(handle_file, &TimeOuts); 
	
	//设置串口配置信息
	DCB device_control_block; //串口结构体
	GetCommState(handle_file, &device_control_block);
	device_control_block.BaudRate = baudrate; //设置波特率
	device_control_block.ByteSize = 8; //8位数据位 
	device_control_block.Parity = NOPARITY; //无奇偶校验位 
	device_control_block.StopBits = ONESTOPBIT; //一个停止位
	SetCommState(handle_file, &device_control_block);	//设置参数到串口句柄
	
	//清空缓存区
	PurgeComm(handle_file, PURGE_TXCLEAR | PURGE_RXCLEAR);

	return TRUE;
}

int serial_read_write()	//读写串口
{
	COMSTAT com_start;
	DWORD errors;
	ClearCommError(handle_file, &errors, &com_start);
	
	char buffer[128];
	DWORD buffer_bytes = sizeof(buffer);
	memset(buffer, 0, sizeof(buffer));
	int result = 0;

	printf("请输入需要发送的数据：");
	gets_s(buffer);

	result = WriteFile(handle_file, buffer, buffer_bytes, &buffer_bytes, NULL);
	if (!result)
	{
		printf("写串口失败!\n");
		return FALSE;
	}
	printf("发送数据：%s。\n", buffer);
	memset(buffer, 0, sizeof(buffer));
	Sleep(100);

	result = ReadFile(handle_file, buffer, buffer_bytes, &buffer_bytes, NULL);
	if (!result)
	{
		printf("读串口失败!\n");
		return FALSE;
	}
	printf("接收数据：%s\n", buffer);
	memset(buffer, 0, sizeof(buffer));
	Sleep(100);

	PurgeComm(handle_file, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);
	return TRUE;
}

void serial_close(void)		//关闭串口
{
	CloseHandle(handle_file);
}

int main()
{
	char serial_port[20];
	memset(serial_port, 0, sizeof(serial_port));
	printf("请输入串口号：");
	gets_s(serial_port);
	printf("串口设置为：%s\n", serial_port);
	serial_open(LPCWSTR(serial_port), 9600); //打开串口，波特率
	//serial_open(_T("COM1"), 9600); //打开串口，波特率
	serial_read_write(); //接收发送字符
	serial_close(); //关闭串口
	system("pause");
	return 0;
}