mschartintroduce.txt

对MSCHART这个控件的具体操作以及一些代码操作

          //修正水平滚动条的显示   
          DrawPic();//调用函数,刷新曲线显示   
    
          CDialog::OnTimer(nIDEvent);   
  }   
  void   CAbcDlg::DrawPic()   {   
  char   s[10];   
          UINT   row   =   1;   
          pDataDB－>MoveFirst();   
  pDataDB－>Move(theApp.nBottomPos);   
  //只从数据库中取某时间段的数据进行显示   
          while   ((!pDataDB－>IsEOF())   ＆＆   (row   <=   10)){   
          m_Chart.SetRow(row);   
  m_Chart.SetRowLabel((LPCTSTR)pDataDB   
  －>m_date_time.Format(“％H:％M"));   
  //以采样时刻做x轴的标注   
          m_Chart.SetColumn(1);   
          sprintf(s,   “％6.2f",   pDataDB－>m_No1);   
          m_Chart.SetData((LPCSTR)s);   
          m_Chart.SetColumn(2);   
          sprintf(s,   “％6.2f",   pDataDB－>m_No2);   
          m_Chart.SetData((LPCSTR)s);   
          m_Chart.SetColumn(3);   
          sprintf(s,   “％6.2f",   pDataDB－>m_No3);   
          m_Chart.SetData((LPCSTR)s);   
          pDataDB－>MoveNext();   
          row＋＋;   
          }   
          while   ((row   <=   10)){   
          m_Chart.SetRow(row);   
          m_Chart.SetRowLabel((LPCTSTR)“");   
  m_Chart.GetDataGrid().SetData(row,   1,   0,   1);   
  //采样数据不足10个点,   对应的位置不显示   
          m_Chart.GetDataGrid().SetData(row,   2,   0,   1);   
          m_Chart.GetDataGrid().SetData(row,   3,   0,   1);   
          row＋＋;   
          }   
          m_Chart.Refresh();   
  }   
  void   CAbcDlg::OnHScroll(UINT   nSBCode,     
          UINT   nPos,   CScrollBar＊   pScrollBar)   
{   
          if   (pDataDB－>GetRecordCount()>10)   
      theApp.nBottomRange   =   pDataDB－>GetRecordCount()－10;   
          else   
          theApp.nBottomRange   =   0;   
    m_ScrBottom.SetScrollRange(0,   theApp.nBottomRange);   
          switch   (nSBCode){   
          case   SB_LINERIGHT:   
        if   (theApp.nBottomPos   <   theApp.nBottomRange){   
        theApp.nBottomPos   =   theApp.nBottomPos   ＋   1;   
        m_ScrBottom.SetScrollPos(theApp.nBottomPos);   
          DrawPic();   
          }   
          break;   
          case   SB_LINELEFT:   
          if   (theApp.nBottomPos   >   0){   
        theApp.nBottomPos   =   theApp.nBottomPos   －   1;   
          m_ScrBottom.SetScrollPos(theApp.nBottomPos);   
          DrawPic();   
          }   
          break;   
          }   
          CDialog::OnHScroll(nSBCode,   nPos,   pScrollBar);   
  }   
  void   CAbcDlg::OnVScroll(UINT   nSBCode,     
          UINT   nPos,   CScrollBar＊   pScrollBar)   {   
          VARIANT   var;   
          double   max1,min1,f;   
          switch   (nSBCode){   
          case   SB_LINEDOWN:   
  f   =   m_Chart.GetPlot().GetAxis(1,   var).   
      GetValueScale().GetMinimum()   －   1;   
          if   (f>=0)   {//最小刻度大于等于0,   则可以滚动   
  m_Chart.GetPlot().GetAxis(1,   var).GetValueScale().   
      SetMinimum(f);   
  f   =   m_Chart.GetPlot().GetAxis   
    (1,   var).GetValueScale().GetMaximum()   －   1;   
  m_Chart.GetPlot().GetAxis(1,   var).GetValueScale().   
  SetMaximum(f);   
      pScrollBar－>SetScrollPos(pScrollBar－>GetScrollPos()   ＋   1);   
          m_Chart.Refresh();   
          }   
          break;   
          case   SB_LINEUP:   
  f   =   m_Chart.GetPlot().GetAxis(1,   var).   
  GetValueScale().GetMaximum()   ＋   1;   
          if   (f   <=   50)   {//最大刻度小于等于50,   则可以滚动   
  m_Chart.GetPlot().GetAxis   
  (1,   var).GetValueScale().SetMaximum(f);   
  f   =   m_Chart.GetPlot().GetAxis(1,   var).   
  GetValueScale().GetMinimum()   ＋   1;   
  m_Chart.GetPlot().GetAxis(1,   var).GetValueScale().   
      SetMinimum(f);   
      pScrollBar－>SetScrollPos(pScrollBar－>GetScrollPos()   －   1);   
          m_Chart.Refresh();   
          }   
          break;   
          }   
          CDialog::OnVScroll(nSBCode,   nPos,   pScrollBar);   
  }   
    
  ----特别注意，程序中用到的关于控件的类，如CVcAxis等，   需要在AbcDlg.cpp文件的开始处说明：＃include   “VcAxis.h"。     
    
  ----限于篇幅，文中仅仅是一个简单示例的部分代码。在实际   应用中，一般会有更多的需求，比如：对坐标轴进行缩放显示；采样有可能得不到正确   的采样值时曲线显示不连续等等，这时需要根据需求编写相应代码。     
  Passing   an   Array   of   Values   to   the   Visual   C++   MSChart   OCX       
  Great   step-by-step   instructions   to   passing   data   to   the   VC++   MSChart   component     
    
  Published     July   27,   2000         
  By     JL   Colson     
      
    
    
  　     
    
  Step   1   :   Creating   the   Project   
  Start   Visual   C++   en   create   a   simple   dialog   based   application   labelled   "Graph"     
  Step   2   :   Add   the   MSChart   OCX   to   Your   Project   
  Select   "project   menu"   option   and   select   "Components   and   contols"   and   then   choose   the   MSChart   component   and   click   "add."     
    
    
      
    
    
  Step   3   :   Add   the   MSChart   OCX   to   Your   Dialog   
  Select   resources   view   tab   and   open   the   main   dialog.   (It抯   a   simple   dialog-based   application).   Drop   the   ocx   on   your   dialog   .     
  Now,   label   your   Chart   "IDC_MSCAHRT1"   
    
    
    
      
  Now,   choose   menu   option   "   Classwizard   "   to   create   a   member   variable   of   your   chart   labelled   "m_Chart"     
    
  　     
    
  Step   4:   Add   the   Code   
  Now   add   a   button   labeled   "Go"   to   your   dialog.   Double-click   it   to   edit   the   code   and   add   the   following   code   in   the   On_Go   function:     
    
  COleSafeArray   saRet;   
    
  DWORD   numElements[]   =   {10,   10};   //   10x10   
    
  //   Create   the   safe-array...   
    
  saRet.Create(VT_R8,   2,   numElements);   
    
  //   Initialize   it   with   values...   
    
  long   index[2];   
    
  for(index[0]=0;   index[0]<10;   index[0]++)   {   
    for(index[1]=0;   index[1]<10;   index[1]++)   {   
      double   val   =   index[0]   +   index[1]*10;   
      saRet.PutElement(index,   &val);   
    }   
  }   
    
  //   Return   the   safe-array   encapsulated   in   a   VARIANT...   
    
  m_Chart.SetChartData(saRet.Detach());   
    
  m_Chart.Refresh;     
    
  Step   5:   Building   and   Running   the   Application   
  Build   and   execute   your   app,   then   click   the   "Go"   button.   Here   is   the   result   .