C++串口通信收到的数据有一部分乱码

#include <iostream>

#include <windows.h>

using namespace std;

HANDLE hMutex;

  

DWORD WINAPI Read(LPVOID lpParamter)

{   

    //打开端口

    HANDLE hCom = CreateFileA("com7", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, 0);

    //设置超时

    COMMTIMEOUTS timeouts;

    GetCommTimeouts(hCom, &timeouts);

    timeouts.ReadIntervalTimeout = 0;

    timeouts.ReadTotalTimeoutMultiplier = 0;

    timeouts.ReadTotalTimeoutConstant = 1;

    timeouts.WriteTotalTimeoutMultiplier = 0;

    timeouts.WriteTotalTimeoutConstant = 0;

    if (!SetCommTimeouts(hCom, &timeouts))

    {

        cout<<"超时设置失败！重新";

        CloseHandle(hCom);

        return 0;

    }

  

    //取得并设置端口状态

    DCB dcb;

    GetCommState(hCom, &dcb);

    dcb.DCBlength = sizeof(DCB);

    dcb.BaudRate = 9600;

    dcb.Parity = 0;  

    dcb.ByteSize = 8;

    dcb.StopBits = ONESTOPBIT;   

    if (!SetCommState(hCom, &dcb))

    {

        cout<<"端口状态设置失败！重新";

        CloseHandle(hCom);

        return 0;

    }

  

  

    char buffer[1024];

    DWORD readsize,dwError; 

    BOOL bReadStatus;

    COMSTAT cs;

  

    WaitForSingleObject(hMutex, INFINITE);

    while(1)

    {   

        readsize = 0;

        ClearCommError(hCom,&dwError,&cs);//取得状态

        //数据是否大于所准备缓冲区

        if(cs.cbInQue>sizeof(buffer))

        {

            PurgeComm(hCom,PURGE_RXCLEAR);//清除通信端口数据

            return 0;

        }

        memset(buffer, 0 , sizeof(buffer));

        bReadStatus = ReadFile(hCom, buffer, cs.cbInQue, &readsize, 0);

        if(readsize>0)

            {

                cout<<cs.cbInQue;

                buffer[cs.cbInQue]='\0';

                std::cout<<buffer;

            }

        Sleep(5);

    }

    ReleaseMutex(hMutex);

    CloseHandle(hCom);

}

  

void main()

{

    HANDLE hThread = CreateThread(NULL, 0, Read, NULL, 0, NULL);

    hMutex = CreateMutex(NULL, FALSE, NULL);

    CloseHandle(hThread);

    while(1)

        Sleep(1000); 

}