关于VC方面的一个小问题

这是代码,,那个高手指点小第一下啊,,
// USBPortDlg.cpp : implementation file
//#include "stdafx.h"
#include "USBPort.h"
#include "USBPortDlg.h"
#include "setupapi.h"
#include "hidsdi.h"#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App Aboutclass CAboutDlg : public CDialog
{
public:
CAboutDlg();// Dialog Data
//{{AFX_DATA(CAboutDlg)
enum { IDD = IDD_ABOUTBOX };
//}}AFX_DATA // ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CAboutDlg)
protected:
virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
//}}AFX_VIRTUAL// Implementation
protected:
//{{AFX_MSG(CAboutDlg)
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
//{{AFX_DATA_INIT(CAboutDlg)
//}}AFX_DATA_INIT
}void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CAboutDlg)
//}}AFX_DATA_MAP
}BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
//{{AFX_MSG_MAP(CAboutDlg)
// No message handlers
//}}AFX_MSG_MAP
END_MESSAGE_MAP()/////////////////////////////////////////////////////////////////////////////
// CUSBPortDlg dialogCUSBPortDlg::CUSBPortDlg(CWnd* pParent /*=NULL*/)
: CDialog(CUSBPortDlg::IDD, pParent)
{
//{{AFX_DATA_INIT(CUSBPortDlg)
// NOTE: the ClassWizard will add member initialization here
//}}AFX_DATA_INIT
// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}void CUSBPortDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(CUSBPortDlg)
// NOTE: the ClassWizard will add DDX and DDV calls here
//}}AFX_DATA_MAP
}BEGIN_MESSAGE_MAP(CUSBPortDlg, CDialog)
//{{AFX_MSG_MAP(CUSBPortDlg)
ON_WM_SYSCOMMAND()
ON_WM_PAINT()
ON_WM_QUERYDRAGICON()
ON_BN_CLICKED(IDC_FIND, OnSearch)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()/////////////////////////////////////////////////////////////////////////////
// CUSBPortDlg message handlersBOOL CUSBPortDlg::OnInitDialog()
{
CDialog::OnInitDialog(); // Add "About..." menu item to system menu. // IDM_ABOUTBOX must be in the system command range.
ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
ASSERT(IDM_ABOUTBOX < 0xF000); CMenu* pSysMenu = GetSystemMenu(FALSE);
if (pSysMenu != NULL)
{
CString strAboutMenu;
strAboutMenu.LoadString(IDS_ABOUTBOX);
if (!strAboutMenu.IsEmpty())
{
pSysMenu->AppendMenu(MF_SEPARATOR);
pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
}
} // Set the icon for this dialog.  The framework does this automatically
//  when the application's main window is not a dialog
SetIcon(m_hIcon, TRUE); // Set big icon
SetIcon(m_hIcon, FALSE); // Set small icon

// TODO: Add extra initialization here
GetDlgItem(IDC_FIND)->SetFocus();
return FALSE;  // return TRUE  unless you set the focus to a control
}void CUSBPortDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
if ((nID & 0xFFF0) == IDM_ABOUTBOX)
{
CAboutDlg dlgAbout;
dlgAbout.DoModal();
}
else
{
CDialog::OnSysCommand(nID, lParam);
}
}// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.void CUSBPortDlg::OnPaint() 
{
if (IsIconic())
{
CPaintDC dc(this); // device context for painting SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0); // Center icon in client rectangle
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; // Draw the icon
dc.DrawIcon(x, y, m_hIcon);
}
else
{
CDialog::OnPaint();
}
}// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CUSBPortDlg::OnQueryDragIcon()
{
return (HCURSOR) m_hIcon;
}void CUSBPortDlg::OnSearch() 
{
// TODO: Add your control notification handler code here
m_strLog.Empty(); m_strLog = _T("正在查找系统中HID类的GUID标识...\r\n");
SetDlgItemText(IDC_EDIT_REPORT,m_strLog); // 查找本系统中HID类的GUID标识
GUID guidHID;
HidD_GetHidGuid(&guidHID);
m_strLog += _T("HID类的GUID标识为\r\n"); CString strShow;
strShow.Format("%08x-%04x-%04x-%02x-%02x-%02x-%02x-%02x-%02x-%02x-%02x\r\n",
guidHID.Data1,guidHID.Data2,guidHID.Data3,guidHID.Data4[0],
guidHID.Data4[1],guidHID.Data4[2],guidHID.Data4[3],guidHID.Data4[4],
guidHID.Data4[5],guidHID.Data4[6],guidHID.Data4[7]); m_strLog += strShow;
SetDlgItemText(IDC_EDIT_REPORT,m_strLog); // 准备查找符合HID规范的USB设备
HDEVINFO hDevInfo = SetupDiGetClassDevs(&guidHID,NULL,0,
DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);

UINT nIndex = 0;
m_strLog += _T("正在查找可用的USB设备...\r\n");
SetDlgItemText(IDC_EDIT_REPORT,m_strLog); // 查找USB设备接口
SP_DEVICE_INTERFACE_DATA strtInterfaceData;
BOOL bSuccess = SetupDiEnumDeviceInterfaces(hDevInfo,NULL,&guidHID,0,
&strtInterfaceData);
if (!bSuccess)
{
m_strLog += _T("抱歉，未找到可用的USB设备");
SetupDiDestroyDeviceInfoList(hDevInfo);
return;
} // 若找到了设备，则读取设备路径名
SP_DEVICE_INTERFACE_DETAIL_DATA strtDetailData;
if (!SetupDiGetDeviceInterfaceDetail(hDevInfo,&strtInterfaceData,
&strtDetailData,sizeof(strtDetailData),NULL,NULL))
{
AfxMessageBox(_T("查找设备路径时出错!"));
SetupDiDestroyDeviceInfoList(hDevInfo);
return;
} // 找到了设备路径
m_strPath = strtDetailData.DevicePath;
strShow.Format("可以通过路径%s访问设备\r\n",m_strPath);
m_strLog += strShow;
SetDlgItemText(IDC_EDIT_REPORT,m_strLog); // 开放与设备的通信
HANDLE hCom = CreateFile(m_strPath,GENERIC_READ | GENERIC_WRITE,
0,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,NULL);
if (hCom = INVALID_HANDLE_VALUE)
{
AfxMessageBox(_T("无法打开通信端口"));
SetupDiDestroyDeviceInfoList(hDevInfo);
return;
} // 查询设备标识
HIDD_ATTRIBUTES strtAttrib;
m_strPath += _T("正在读取设备的标识...\r\n");
SetDlgItemText(IDC_EDIT_REPORT,m_strPath); if (!HidD_GetAttributes(hCom,&strtAttrib))
{
AfxMessageBox(_T("查询设备状态时出错!"));
CloseHandle(hCom);
SetupDiDestroyDeviceInfoList(hDevInfo);
} // 将有关该设备的标识显示出来
m_strPath += _T("已读取，见右边所示\r\n");
SetDlgItemText(IDC_EDIT_REPORT,m_strPath); // 显示供应商标识
strShow.Format("0x%x",strtAttrib.VendorID);
SetDlgItemText(IDC_ID_VENDOR,strShow); // 显示产品标识
strShow.Format("0x%x",strtAttrib.ProductID);
SetDlgItemText(IDC_ID_PRODUCT,strShow); // 显示产品版本号
strShow.Format("%d",strtAttrib.VersionNumber);
SetDlgItemText(IDC_ID_VERSION,strShow); // 释放资源
CloseHandle(hCom);
SetupDiDestroyDeviceInfoList(hDevInfo);
}