MFC--根据串口采集的数据借助GDI绘制曲线

  1 #pragma once
  2 
  3 
  4 
  5 //用于绘制二维曲线
  6 class CDrawView : public CWnd
  7 {
  8     DECLARE_DYNCREATE(CDrawView)
  9 
 10 public:
 11     CDrawView();        
 12     virtual ~CDrawView();
 13     DECLARE_MESSAGE_MAP()
 14 
 15 public:
 16 #ifdef _DEBUG
 17     virtual void AssertValid() const;
 18 #ifndef _WIN32_WCE
 19     virtual void Dump(CDumpContext& dc) const;
 20 #endif
 21 #endif
 22 
 23 public:
 24 
 25 
 26 
 27     CPoint m_dCurrentPosition;     //current position
 28     CPoint m_dPreviousPosition;     //previous position
 29     double m_updateRate;//数据更新率
 30     void setUpdateRate(double updateRate);
 31 
 32     CList<CPoint,CPoint&> dataList;//用于存储真实数据
 33     CList<CPoint,CPoint&> dataList1;//用于绘图
 34     CList<CPoint,CPoint&> tempDataList;//暂存数据
 35     void InvalidateCtrl();
 36     void SetYRange(double dYLower, double dYUpper, int nYDecimalPlaces);
 37     void SetXRange(int dXLower,int dXUpper,int nXDecimalPlaces);
 38     void SetXUnits(CString string);
 39     void SetYUnits(CString string);
 40     void SetGridColor(COLORREF color);
 41     void SetPlotColor(COLORREF color);
 42     void SetBackgroundColor(COLORREF color);
 43     void SetTitle(CString title);
 44     void AppendPoint(CPoint *newDataList);
 45     void Reset();
 46     void DrawPoint();
 47 
 48     //各个部分的颜色
 49     COLORREF m_crBackColor;     //backGround color
 50     COLORREF m_crGridColor;     //Grid color
 51     COLORREF m_crPlotColor;     //data plot color
 52 
 53     //设备上下文以及与其相关的位图
 54 
 55     CDC m_dcGrid;
 56     CDC m_dcPlot;
 57     CBitmap *m_pBitmapOldGrid;
 58     CBitmap *m_pBitmapOldPlot;
 59     CBitmap m_pBitmapGrid;
 60     CBitmap m_pBitmapPlot;
 61 
 62 
 63     //画图区域相关
 64     int m_nHalfShiftPixels;
 65     int m_nPlotShiftPixels;
 66     int m_nClientHeight;
 67     int m_nClientWidth;
 68     int m_nPlotHeight;
 69     int m_nPlotWidth;
 70 
 71     //坐标轴Y
 72     double m_dYLowerLimit;
 73     double m_dYUpperLimit;
 74     double m_dYRange;
 75     double m_dVerticalFactor;
 76 
 77     //坐标轴X
 78     int m_dXLowerLimit;
 79     int m_dXUpperLimit;
 80     double m_dXRange;
 81     double m_dHorizontalFactor;
 82 
 83     //title
 84     CString m_sTitile;
 85 
 86     CRect m_rectClient;
 87     CRect m_rectPlot;
 88     CPen  m_penPlot;
 89     CBrush m_brushBack;
 90 
 91     int m_nShiftPixels;          //amount  to  shift with each new point 
 92     int m_nYDecimal;
 93     int m_nXDecimal;
 94 
 95     CString m_strXUnitsString;
 96     CString m_strYUnitsString;
 97 
 98 
 99 
100 
101     CString str;
102     CList<int,int>listOfFogX;
103 
104     afx_msg void OnPaint();
105     BOOL Create(DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT nID=NULL);
106     afx_msg void OnSize(UINT nType, int cx, int cy);
107 };

  1 // DrawView.cpp : 实现文件
  2 //
  3 
  4 #include "stdafx.h"
  5 #include "IMU4.h"
  6 #include "DrawView.h"
  7 #include "math.h"
  8 
  9 
 10 // CDrawView
 11 
 12 IMPLEMENT_DYNCREATE(CDrawView, CWnd)
 13 
 14 CDrawView::CDrawView()
 15 {
 16     m_nYDecimal = 3 ;
 17 
 18     m_dPreviousPosition.x = 0;
 19     m_dPreviousPosition.y = 0;
 20 
 21     m_dCurrentPosition.x = 0;
 22     m_dCurrentPosition.y = 0;
 23 
 24     m_dYLowerLimit = -10.0 ;
 25     m_dYUpperLimit =  10.0 ;
 26     m_dYRange =  m_dYUpperLimit - m_dYLowerLimit ;   
 27 
 28     m_dXLowerLimit = 0;
 29     m_dXUpperLimit = 1000;
 30     m_dXRange = m_dXUpperLimit - m_dXLowerLimit;
 31 
 32     m_dVerticalFactor = (double)m_nPlotHeight / m_dYRange ; 
 33     m_dHorizontalFactor = (double)m_nClientWidth / m_dXRange / 100.0;
 34 
 35     m_nShiftPixels     = 4 ;
 36     m_nHalfShiftPixels = m_nShiftPixels/2 ;                     
 37     m_nPlotShiftPixels = m_nShiftPixels + m_nHalfShiftPixels ;  
 38 
 39     m_crBackColor  = RGB(  0,   0,   0) ;  
 40     m_crGridColor  = RGB(  0, 255, 255) ;  
 41     m_crPlotColor  = RGB(255, 255, 255) ;  
 42 
 43     m_penPlot.CreatePen(PS_SOLID, 0, m_crPlotColor) ;
 44     m_brushBack.CreateSolidBrush(m_crBackColor) ;
 45 
 46     m_strXUnitsString.Format(_T("")) ;  
 47     m_strYUnitsString.Format(_T("")) ;  
 48 
 49     m_pBitmapOldGrid = NULL ;
 50 }
 51 
 52 CDrawView::~CDrawView()
 53 {
 54 
 55 }
 56 
 57 
 58 BEGIN_MESSAGE_MAP(CDrawView, CWnd)
 59     ON_WM_MOUSEACTIVATE()
 60     ON_WM_DESTROY()
 61     ON_WM_PAINT()
 62     ON_WM_SIZE()
 63     ON_WM_TIMER()
 64 END_MESSAGE_MAP()
 65 
 66 
 67 
 68 #ifdef _DEBUG
 69 void CDrawView::AssertValid() const
 70 {
 71     CWnd::AssertValid();
 72 }
 73 
 74 #ifndef _WIN32_WCE
 75 void CDrawView::Dump(CDumpContext& dc) const
 76 {
 77     CWnd::Dump(dc);
 78 }
 79 #endif
 80 #endif
 81 void CDrawView::InvalidateCtrl()
 82 {
 83     //用于画坐标轴等信息的函数
 84     int i;
 85     int nCharacters;
 86     int nTopGridPix,nMidGridPix,nBottomGridPix;//分别代表绘图区的三条线（暂定）
 87 
 88     CPen *oldPen;
 89     CPen solidPen(PS_SOLID,0,m_crGridColor);//建立一个画实线的画笔对象
 90     CFont axisFont,yUnitFont,*oldFont;//建立三个字体对象
 91     CString strTemp = _T("0");
 92 
 93     CClientDC dc(this);
 94     if(m_dcGrid.GetSafeHdc() == NULL)
 95     {
 96         m_dcGrid.CreateCompatibleDC(&dc);    
 97         m_pBitmapGrid.CreateCompatibleBitmap(&dc,m_nClientWidth,m_nClientHeight);    
 98         m_pBitmapOldGrid = m_dcGrid.SelectObject(&m_pBitmapGrid);
 99     }
100     m_dcGrid.SetBkColor(m_crBackColor);
101     m_dcGrid.FillRect(m_rectClient, &m_brushBack) ;    
102     nCharacters = max(abs((int)log10(fabs(m_dYUpperLimit))),abs((int)log10(fabs(m_dYLowerLimit))));
103     nCharacters = nCharacters + 4 + m_nYDecimal;
104 
105     m_rectPlot.left = m_rectClient.left + 6 * nCharacters;
106     m_nPlotWidth = m_rectPlot.Width();
107 
108     //draw the plot rectangle
109     oldPen = m_dcGrid.SelectObject(&solidPen);
110     m_dcGrid.MoveTo(m_rectPlot.left,m_rectPlot.top);
111     m_dcGrid.LineTo(m_rectPlot.right + 1,m_rectPlot.top);
112     m_dcGrid.LineTo(m_rectPlot.right + 1,m_rectPlot.bottom + 1);
113     m_dcGrid.LineTo(m_rectPlot.left,m_rectPlot.bottom + 1);
114     m_dcGrid.LineTo(m_rectPlot.left,m_rectPlot.top);
115 
116     //draw the dotted lines,
117     //use setPixel instead of a dotted pen - this allows for a 
118     //finer  dotted line  and a more "" technical "look
119     nMidGridPix = (m_rectPlot.top + m_rectPlot.bottom) / 2;
120     nTopGridPix = nMidGridPix - m_nPlotHeight / 4;
121     nBottomGridPix = nMidGridPix + m_nPlotHeight / 4;
122 
123     for(i = m_rectPlot.left; i < m_rectPlot.right; i+= 4)
124     {
125         m_dcGrid.SetPixel(i,nTopGridPix,m_crGridColor);
126         m_dcGrid.SetPixel(i,nMidGridPix,m_crGridColor);
127         m_dcGrid.SetPixel(i,nBottomGridPix,m_crGridColor);
128     }
129 
130     //create some fonts (horiaontal  and vertical )
131     //use a height  of 14 pixels and 300 weight
132     //(this may need  to be adjusted depending on the display )
133 
134     axisFont.CreateFont (14, 0, 0, 0, 300,
135                        FALSE, FALSE, 0, ANSI_CHARSET,
136                        OUT_DEFAULT_PRECIS, 
137                        CLIP_DEFAULT_PRECIS,
138                        DEFAULT_QUALITY, 
139                        DEFAULT_PITCH|FF_SWISS, _T("Arial"));
140     yUnitFont.CreateFont (14, 0, 900, 0, 300,
141                        FALSE, FALSE, 0, ANSI_CHARSET,
142                        OUT_DEFAULT_PRECIS, 
143                        CLIP_DEFAULT_PRECIS,
144                        DEFAULT_QUALITY, 
145                        DEFAULT_PITCH|FF_SWISS, _T("Arial")) ;
146 
147     //grab the horizontal font
148     oldFont = m_dcGrid.SelectObject(&axisFont);
149 
150     //y max
151     m_dcGrid.SetTextColor(m_crGridColor);
152     m_dcGrid.SetTextAlign(TA_RIGHT|TA_TOP);
153     strTemp.Format (_T("%.*lf"),m_nYDecimal, m_dYUpperLimit) ;//*号会被m_nYDecimals取代，表示保留几位小数
154     m_dcGrid.TextOutW(m_rectPlot.left - 4,m_rectPlot.top,strTemp);
155 
156     m_dcGrid.SetTextAlign (TA_LEFT|TA_TOP) ;
157     m_dcGrid.TextOut (m_rectPlot.left - 4, m_rectPlot.bottom - (0 - m_dYLowerLimit) * m_dVerticalFactor, _T("0")) ;
158     //y min 
159     m_dcGrid.SetTextAlign(TA_RIGHT|TA_BASELINE);
160     strTemp.Format(_T("%.*lf"),m_nYDecimal,m_dYLowerLimit);
161     m_dcGrid.TextOutW(m_rectPlot.left - 4,m_rectPlot.bottom,strTemp);
162 
163     //x min
164     m_dcGrid.SetTextAlign (TA_LEFT|TA_TOP) ;
165     m_dcGrid.TextOut (m_rectPlot.left, m_rectPlot.bottom+4, _T("0")) ;
166     //横坐标
167     for(int i = 1;i <= 5;i++)
168     {
169         m_dcGrid.SetTextAlign(TA_CENTER|TA_TOP);
170         strTemp.Format(_T("%d"),m_dXUpperLimit * i / 6);
171         m_dcGrid.TextOut((m_rectPlot.left + m_nPlotWidth * i / 6),m_rectPlot.bottom + 4, strTemp);
172     }
173     // x max
174      m_dcGrid.SetTextAlign (TA_RIGHT|TA_TOP) ;
175      strTemp.Format (_T("%d"), m_dXUpperLimit) ; 
176      m_dcGrid.TextOut (m_rectPlot.right, m_rectPlot.bottom+4, strTemp) ;
177 
178      // x units
179     m_dcGrid.SetTextAlign (TA_CENTER|TA_TOP) ;
180     m_dcGrid.TextOut (m_rectPlot.right - 70, 
181                     m_rectPlot.bottom+4, m_strXUnitsString) ;
182     //title
183     m_dcGrid.SetTextAlign (TA_CENTER|TA_TOP) ;
184     m_dcGrid.TextOut ((m_rectPlot.left+m_rectPlot.right)/2, 
185         m_rectPlot.top-17, m_sTitile) ;
186 
187     // restore the font
188     m_dcGrid.SelectObject(oldFont) ;
189     // y units
190     oldFont = m_dcGrid.SelectObject(&yUnitFont) ;
191     m_dcGrid.SetTextAlign (TA_CENTER|TA_BASELINE) ;
192     m_dcGrid.TextOut ((m_rectClient.left+m_rectPlot.left)/2, 
193                     (m_rectPlot.bottom+m_rectPlot.top)/2, m_strYUnitsString) ;
194     m_dcGrid.SelectObject(oldFont) ;
195 
196     //创建画曲线的内存DC和兼容Bitmap
197     if (m_dcPlot.GetSafeHdc() == NULL)
198     {
199         m_dcPlot.CreateCompatibleDC(&dc) ;
200         m_pBitmapPlot.CreateCompatibleBitmap(&dc, m_nClientWidth, m_nClientHeight) ;
201         m_pBitmapOldPlot = m_dcPlot.SelectObject(&m_pBitmapPlot) ;
202     }
203     // make sure the plot bitmap is cleared
204     m_dcPlot.SetBkColor (m_crBackColor) ;
205     m_dcPlot.FillRect(m_rectClient, &m_brushBack) ;
206 }
207 
208 //set title
209 void CDrawView::SetTitle(CString title)
210 {
211     m_sTitile = title;
212     InvalidateCtrl();
213 }
214 void CDrawView::SetYRange(double dYLower, double dYUpper, int nYDecimalPlaces)
215 {
216   ASSERT(dYUpper > dYLower) ;
217 
218   m_dYLowerLimit     = dYLower ;
219   m_dYUpperLimit     = dYUpper ;
220   m_nYDecimal      = nYDecimalPlaces ;
221   m_dYRange          = m_dYUpperLimit - m_dYLowerLimit ;
222   m_dVerticalFactor = (double)m_nPlotHeight / m_dYRange ; 
223 
224   InvalidateCtrl() ;
225 } // SetYRange
226 
227 void CDrawView::SetXRange(int dXLower,int dXUpper,int nXDecimalPlaces)
228 {
229     ASSERT(dXUpper > dXLower);
230 
231     m_dXLowerLimit = dXLower;
232     m_dXUpperLimit = dXUpper;
233     m_nXDecimal = nXDecimalPlaces;
234     m_dXRange = m_dXUpperLimit - m_dXLowerLimit;
235     m_dHorizontalFactor = (double)m_nPlotWidth / m_dXRange / 400.0 /** (m_updateRate * 400)*/;
236 
237     InvalidateCtrl();
238 }
239 
240 void CDrawView::SetXUnits(CString string)
241 {
242     m_strXUnitsString = string ;
243     InvalidateCtrl() ;
244 
245 }  // SetXUnits
246 
247 
248 void CDrawView::SetYUnits(CString string)
249 {
250     m_strYUnitsString = string ;
251     InvalidateCtrl() ;
252 
253 }  // SetYUnits
254 
255 void CDrawView::SetGridColor(COLORREF color)
256 {
257     m_crGridColor = color ;
258     InvalidateCtrl() ;
259 
260 }  // SetGridColor
261 
262 void CDrawView::SetPlotColor(COLORREF color)
263 {
264     m_crPlotColor = color ;
265 
266     m_penPlot.DeleteObject() ;
267     m_penPlot.CreatePen(PS_SOLID, 0, m_crPlotColor) ;
268     InvalidateCtrl() ;
269 
270 }  // SetPlotColor
271 
272 void CDrawView::SetBackgroundColor(COLORREF color)
273 {
274     m_crBackColor = color ;
275 
276     m_brushBack.DeleteObject() ;
277     m_brushBack.CreateSolidBrush(m_crBackColor) ;
278     InvalidateCtrl() ;
279 
280 }  // SetBackgroundColor
281 
282 void CDrawView::AppendPoint(CPoint *newpPoint)
283 {
284     //在plotBitmap上继续画刚接收到的一个数据点，如果一次画本次接收到的所有数据，耗时严重，实时性不强
285     CPoint dPrevious;
286     
287     dPrevious = m_dCurrentPosition;
288     m_dCurrentPosition = *newpPoint;
289     //根据新来的数据点更新纵坐标
290     if(m_dCurrentPosition.y < m_dYLowerLimit)
291     {
292         m_dYLowerLimit = m_dCurrentPosition.y;
293     }
294     if(m_dCurrentPosition.y > m_dYUpperLimit)
295     {
296         m_dYUpperLimit = m_dCurrentPosition.y;
297     }
298     //将数据保存在链表里用于重绘以及后面的参数计算
299     dataList.AddTail(m_dCurrentPosition);
300     //在plotBitmap上接着画当前数据点
301     DrawPoint();
302     //在界面上显示出来
303     //在这里要注意CClientDC和CPaintDC的区别，一定要避免在OnPaint函数里直接或间接的用CClientDC，这样会使界面一直重绘，造成假死现象
304     if(IsWindow(this->m_hWnd))
305     {
306         CClientDC dc(this) ;  // device context for painting
307         CDC memDC ;            //定义一个内存设备描述表对象（即后备缓冲区）
308         CBitmap memBitmap ;    //定义一个位图对象
309         CBitmap* oldBitmap ; // bitmap originally found in CMemDC
310 
311         if(dc.GetSafeHdc() != NULL)
312         {
313             memDC.CreateCompatibleDC(&dc) ;//建立与屏幕设备描述表（前端缓冲区）兼容的内存设备描述表句柄（后备缓冲区）
314             memBitmap.CreateCompatibleBitmap(&dc, m_nClientWidth, m_nClientHeight) ;//建立一个与屏幕设备描述表（或者内存设备描述表）兼容的位图
315             oldBitmap = (CBitmap *)memDC.SelectObject(&memBitmap) ;//只有选入了位图的设备描述表才有地方绘图，画到指定的位图上
316 
317             if (memDC.GetSafeHdc() != NULL)
318             {
319                 // first drop the grid on the memory dc
320                 memDC.BitBlt(0, 0, m_nClientWidth, m_nClientHeight, 
321                          &m_dcGrid, 0, 0, SRCCOPY) ;
322              // now add the plot on top as a "pattern" via SRCPAINT.
323              // works well with dark background and a light plot
324                 memDC.BitBlt(0, 0, m_nClientWidth, m_nClientHeight, 
325                            &m_dcPlot, 0, 0, SRCPAINT) ;  //SRCPAINT
326              // finally send the result to the display
327                 dc.BitBlt(0, 0, m_nClientWidth, m_nClientHeight, 
328                           &memDC, 0, 0, SRCCOPY) ;
329             }
330 
331             memDC.SelectObject(oldBitmap) ;
332         }
333     }
334 }
335 //将当前数据点绘制到plotBitmap上    
336 void CDrawView::DrawPoint()
337 { 
338     double currX, prevX, currY, prevY ;
339 
340     CPen *oldPen ;
341     CRect rectCleanUp ;
342 
343     if (m_dcPlot.GetSafeHdc() != NULL)
344     {
345 
346         oldPen = m_dcPlot.SelectObject(&m_penPlot) ;
347      // 移到由prevX和prevY指定的前一个位置
348         prevX = m_rectPlot.left +  m_dPreviousPosition.x * m_dHorizontalFactor;
349         prevY = m_rectPlot.bottom - 
350               (long)((m_dPreviousPosition.y - m_dYLowerLimit) * m_dVerticalFactor);
351         m_dcPlot.MoveTo (prevX, prevY);
352 
353      // 画到当前点的位置
354         currX = m_rectPlot.left + m_dCurrentPosition.x * m_dHorizontalFactor;
355         currY = m_rectPlot.bottom - 
356             (long)((m_dCurrentPosition.y - m_dYLowerLimit) * m_dVerticalFactor);
357         m_dcPlot.LineTo (currX, currY);
358 
359     // restore the pen 
360         m_dcPlot.SelectObject(oldPen) ;
361     // store the current point for connection to the next point
362         m_dPreviousPosition.x = m_dCurrentPosition.x ;
363         m_dPreviousPosition.y = m_dCurrentPosition.y;
364   }
365 
366 } // end DrawPoint
367 void CDrawView::OnPaint()
368 {
369         if(m_dcGrid.GetSafeHdc() != NULL)
370         {
371             m_dcGrid.DeleteDC();
372             m_pBitmapGrid.DeleteObject();
373         }
374         if(m_dcPlot.GetSafeHdc() != NULL)
375         {
376             m_dcPlot.DeleteDC();
377             m_pBitmapPlot.DeleteObject();
378         }
379             
380     InvalidateCtrl();
381 
382     double pointX,pointY;
383     CPoint tempPoint;
384     CPen *oldPen1 ;
385     //dataList1.RemoveAll();
386     if(dataList.GetCount() > 1)
387     {
388         //绘图区域大小已经改变，需要重绘
389         if(m_dcPlot.GetSafeHdc() != NULL )
390         {
391             oldPen1 = m_dcPlot.SelectObject(&m_penPlot) ;
392             POSITION pos1 = dataList.GetHeadPosition();
393             
394             tempPoint = dataList.GetNext(pos1);
395             pointX = m_rectPlot.left + tempPoint.x * m_dHorizontalFactor;
396             pointY = m_rectPlot.bottom - 
397                 (long)((tempPoint.y - m_dYLowerLimit) * m_dVerticalFactor);
398             m_dcPlot.MoveTo(pointX,pointY);
399             CString str;
400             str.Format(_T("long is %d"),dataList.GetCount());
401             //TRACE(str);
402             for(int i = 1; i < dataList.GetCount();i++ )
403             {
404                 tempPoint = dataList.GetNext(pos1);
405                 pointX = m_rectPlot.left + tempPoint.x * m_dHorizontalFactor;
406                 pointY = m_rectPlot.bottom - 
407                 (long)((tempPoint.y - m_dYLowerLimit) * m_dVerticalFactor);
408                 m_dcPlot.LineTo(pointX,pointY);
409                 m_dcPlot.MoveTo(pointX,pointY);
410             }
411             m_dcPlot.SelectObject(oldPen1);
412         }
413     }
414 
415 
416     if(m_nClientHeight != 0)
417     {
418         CPaintDC dc(this) ;  // device context for painting
419     
420         CDC memDC ;            //定义一个内存设备描述表对象（即后备缓冲区）
421         CBitmap memBitmap ;    //定义一个位图对象
422         CBitmap* oldBitmap ; // bitmap originally found in CMemDC
423 
424         memDC.CreateCompatibleDC(&dc) ;//建立与屏幕设备描述表（前端缓冲区）兼容的内存设备描述表句柄（后备缓冲区）
425         memBitmap.CreateCompatibleBitmap(&dc, m_nClientWidth, m_nClientHeight) ;//建立一个与屏幕设备描述表（或者内存设备描述表）兼容的位图
426         oldBitmap = (CBitmap *)memDC.SelectObject(&memBitmap) ;//只有选入了位图的设备描述表才有地方绘图，画到指定的位图上
427     
428         if (memDC.GetSafeHdc() != NULL)
429         {
430             
431              //first drop the grid on the memory dc
432             memDC.BitBlt(0, 0, m_nClientWidth, m_nClientHeight, 
433                  &m_dcGrid, 0, 0, SRCCOPY) ;
434              // now add the plot on top as a "pattern" via SRCPAINT.
435          // works well with dark background and a light plot
436     
437             memDC.BitBlt(0, 0, m_nPlotWidth, m_nPlotHeight, 
438                    &m_dcPlot, 0, 0, SRCPAINT) ;  //SRCPAINT
439           //finally send the result to the display    
440             dc.BitBlt(0, 0, m_nClientWidth, m_nClientHeight, 
441                   &memDC, 0, 0, SRCCOPY) ;
442             
443         }
444 
445         memDC.SelectObject(oldBitmap) ;
446         memDC.DeleteDC();
447         memBitmap.DeleteObject();
448     }    
449 }
450 
451 
452 void CDrawView::Reset()
453 {
454   InvalidateCtrl() ;
455 }        
456 
457 
458 BOOL CDrawView::Create(DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT nID)
459 {
460     // TODO: 在此添加专用代码和/或调用基类
461     BOOL result;
462     static CString className = AfxRegisterWndClass(CS_HREDRAW|CS_VREDRAW);//注册窗口类，返回值包含创建的窗口类的信息
463     result = CWnd::CreateEx(WS_EX_CLIENTEDGE | WS_EX_STATICEDGE, 
464                           className, NULL, dwStyle, 
465                           rect.left, rect.top, rect.right-rect.left, rect.bottom-rect.top,
466                           pParentWnd->GetSafeHwnd(), (HMENU)nID) ;
467     m_dPreviousPosition.x = 0;
468     m_dPreviousPosition.y = 0;
469 
470     m_dCurrentPosition.x = 0;
471     m_dCurrentPosition.y = 0;
472     if (result != 0)
473         // InvalidateCtrl() ;
474     
475     return result ;
476 }
477 
478 
479 void CDrawView::OnSize(UINT nType, int cx, int cy)
480 {
481     CWnd::OnSize(nType, cx, cy);
482 
483     GetClientRect(&m_rectClient) ;
484     // set some member variables to avoid multiple function calls
485     m_nClientHeight = m_rectClient.Height() ;
486     m_nClientWidth  = m_rectClient.Width() ;
487     // the "left" coordinate and "width" will be modified in 
488     // InvalidateCtrl to be based on the width of the y axis scaling
489     m_rectPlot.left   = 20 ;  
490     m_rectPlot.top    = 25;
491     m_rectPlot.right  = m_rectClient.right-10 ;
492     m_rectPlot.bottom = m_rectClient.bottom-25 ;
493 
494     // set some member variables to avoid multiple function calls
495     m_nPlotHeight = m_rectPlot.Height() ;
496     m_nPlotWidth  = m_rectPlot.Width() ;
497 
498     // set the scaling factor for now, this can be adjusted 
499     // in the SetRange functions
500     m_dVerticalFactor = (double)m_nPlotHeight / m_dYRange ; 
501     m_dHorizontalFactor = (double)m_nClientWidth / m_dXRange /400.0 /** (m_updateRate * 400)*/;
502     
503 }
504 void CDrawView::setUpdateRate(double updateRate)
505 {
506     m_updateRate = updateRate;
507 }