MFC记录式文件的读写

来源：互联网发布：java 垃圾回收面试题编辑：程序博客网时间：2024/06/04 19:30

//创建

dataFileTemp.Open(strPathTemp,CFile::modeCreate|CFile::modeWrite);
dataFileTemp.SeekToBegin();

//关闭

dataFileTemp.Close();
//打开

if(dataFileTemp.Open(strPathTemp,CFile::modeWrite))
{
dataFileTemp.SeekToEnd();

   //写入
    dataFileTemp.Write(&g_TestDatas, sizeof(g_TestDatas));
    dataFileTemp.Close();
   }

//删除

dataFileTemp.Remove(strPathTemp);

*******************************************************定位读写****************************************************

typedef struct tagTestDatas
{
tagTestDatas()
{
  dTemperature = 0;
  dHumidity = 0;
  dEnvHumidity = 0;
  dFlowRate = 0;
  dOxyAD = 0;

dOTR = 0;
  dppm = 0;
  dtime = 0;
  dValtage = 0;
  dVsteam = 0;
  dZeroppm = 0;
}

double dTemperature;
double dHumidity;//上腔湿度
double dEnvHumidity;//环境湿度
double dFlowRate;
double dOxyAD;
double dOTR;
double dppm;

double dtime;
double dValtage;
double dVsteam;
double dZeroppm;
double dStandardOTR;;
} TESTDATAS;

void CDetailedDataDlg::OnBnClickedButton1()
{

DOUBLE dvalue = 0;
CString strText;
TESTDATAS data;
CFile dataFile;
dataFile.Open(strFileNameCur,CFile::modeRead);
int nRecord = dataFile.GetLength()/sizeof(data);

int i=0;
//重新定位

  int CurRecNum;
  int CurRec;
  int totalRec=0;
  if(nRecord % 1000!=0)
   totalRec=nRecord / 1000+1;
  else
   totalRec=nRecord / 1000;

if (m_RecordNum/sizeof(data)==nRecord)
  {
          CurRecNum=m_RecordNum-(1000+nRecord % 1000)*sizeof(data);
     GetDlgItem(IDC_BUTTON2)->EnableWindow(TRUE);
          CurRec=totalRec-1;
  }
  else

{
   CurRecNum=m_RecordNum-2000*sizeof(data);
   if (CurRecNum==0)
   {
             GetDlgItem(IDC_BUTTON1)->EnableWindow(FALSE);
      CurRec=1;
   }
   else
   {
     CurRec=CurRecNum/sizeof(data)/1000+1;
   }
  }

//文件绝对定位

dataFile.Seek(CurRecNum,CFile::begin);
  CString strRec;
  strRec.Format(_T("%d/%d"),CurRec,totalRec);
  if (CurRec==1)
  {
    GetDlgItem(IDC_BUTTON1)->EnableWindow(FALSE);
  }

GetDlgItem(IDC_STATIC1)->SetWindowText(strRec);

  m_RecordNum=CurRecNum+1000*sizeof(data);
  int j=CurRecNum/sizeof(data);
  //下一页可用
  GetDlgItem(IDC_BUTTON2)->EnableWindow(TRUE);
  m_DataList.DeleteAllItems();

for(i=0; i<1000; i++)
  {
   dataFile.Read(&data,sizeof(data));
           j++;
   strText.Format(_T("%d"), j);
   m_DataList.InsertItem(i, strText);

dvalue = data.dTemperature;
   strText.Format(_T("%.1f"),dvalue);
   m_DataList.SetItemText(i, 1, strText);

}
dataFile.Close();

UpdateData(FALSE);
}