MFC 使用用指定USB设备串口

在做设备串口通讯时，往往需要自动连接到想要连接的usb转串口设备上。

#include <Setupapi.h>
int CMFCApplication1Dlg::FindUSBCOM()
{
#pragma comment(lib, "setupapi.lib")
    HDEVINFO hDevInfo = SetupDiGetClassDevs(NULL, NULL, NULL, DIGCF_ALLCLASSES | DIGCF_PRESENT);
    if (hDevInfo == INVALID_HANDLE_VALUE)
    {
        AfxMessageBox(_T("获取系统设备列表失败"));
        return -1;
    }
    SP_DEVINFO_DATA deviceInfoData;
    deviceInfoData.cbSize = sizeof(SP_DEVINFO_DATA);
    deviceInfoData.DevInst = 0;
    deviceInfoData.Reserved = 0;


    DWORD regDataType;
    LPTSTR buffer = new TCHAR[200];
    DWORD buffersize = 200;

    LPTSTR bufferVid = new TCHAR[200];
    DWORD buffersizeVid = 200;

    LPTSTR bufferPortNum = new TCHAR[200];
    DWORD buffersizePortNum = 200;

    int portNum = 0;//Com1 portNum=1

    for (int i = 0; SetupDiEnumDeviceInfo(hDevInfo, i, &deviceInfoData); i++)
    {

        
        buffersize = 200;
        SetupDiGetDeviceRegistryProperty(hDevInfo, &deviceInfoData, SPDRP_CLASS, &regDataType, (PBYTE)buffer, buffersize, &buffersize);

        if (CString(buffer).MakeUpper() == "PORTS")
        {
            
            buffersizePortNum = 200;            
            SetupDiGetDeviceRegistryProperty(hDevInfo, &deviceInfoData, SPDRP_FRIENDLYNAME, &regDataType, (PBYTE)bufferPortNum, buffersizePortNum, &buffersizePortNum);
            int comIndex = CString(bufferPortNum).MakeUpper().Find(_T("COM"));
            if (comIndex > -1)
            {
                //Silicon Labs CP210x USB to UART Bridge (COM4)            
                portNum = _ttoi(CString(bufferPortNum).Mid(comIndex + 3, 1));

            }
        
            buffersizeVid = 200;
            SetupDiGetDeviceRegistryProperty(hDevInfo, &deviceInfoData, SPDRP_HARDWAREID, &regDataType, (PBYTE)bufferVid, buffersizeVid, &buffersizeVid);

            if (CString(bufferVid).MakeUpper().Find(_T("VID_10C4")) > -1)
            {
                if (buffer != nullptr)
                {
                    delete[] buffer;
                }
                if (bufferVid != nullptr)
                {
                    delete[] bufferVid;
                }
                if (bufferPortNum != nullptr)
                {
                    delete[] bufferPortNum;
                }
                // 释放设备  
                SetupDiDestroyDeviceInfoList(hDevInfo);
                return portNum;

            }

        }//end if ports


    }// end for
    if (buffer != nullptr)
    {
        delete[] buffer;
    }
    if (bufferVid != nullptr)
    {
        delete[] bufferVid;
    }
    if (bufferPortNum != nullptr)
    {
        delete[] bufferPortNum;
    }
    // 释放设备  
    SetupDiDestroyDeviceInfoList(hDevInfo);
    return portNum;
}