实例详解：MFC坐标轴实现

需求：MFC坐标轴实现-----最好有步骤啊，刚刚才接触C++和MFC啊。MFC怎样在特定区域建立坐标轴,x轴自适应,y轴有固定范围,最好有网格。

解决思路：VC 内存绘图,不闪屏，具体代码如下：

// 先上传代码，在.h 文件中：

#pragma once  

#include <afxtempl.h>  

#define TEXT_AREA_WIDTH     (60)            ///< 文字区宽度,单位 像素
#define X_AXIS_GRAD         (600)           ///< X 轴刻度值
#define Y_AXIS_GRAD         (50)            ///< X 轴刻度值  

class My_Draw  : public CStatic
{
    // 构造/析构 函数
public:
        My_Draw();
        virtual ~My_Draw();
public:
    struct
    {
        unsigned char Show_Max_Grid                 :;         // 是否显示大网格
        unsigned char Show_Min_Grid                 :;         // 是否显示小网格
        unsigned char Draw_Enable                   :;         // 放大/缩小使能位
        unsigned char Draw_Line_Choice              :;         // 线被选择
        unsigned char LButton_Down_Flag             :;         // 鼠标左键按下标志
        unsigned char LButton_Up_Flag               :;         // 鼠标左键弹起标志
        unsigned char LButton_Double_Down_Flag      :;         // 鼠标左键双击按下标志
    }Bool_Flag;  

    unsigned int TextAreaWidth;
    int xAxisGrad,yAxisGrad;
    unsigned short xMaxGrad,xMinGrad;
    unsigned short yMaxGrad,yMinGrad;  

    int Limit_Min,Limit_Max;  

    POINT Mouse_Current_Point;                      // 鼠标当前坐标
    POINT Button_Down_Point;                        // 记录鼠标左键按下时的坐标
    POINT LButton_Double_Down_Point;                // 记录鼠标左键双击按下的坐标
    POINT Old_LButton_Double_Down_Point;  

    // 画笔列表
    CPen* pBrack;       // 黑色画笔
    CPen* pBlue;        // 蓝色画笔
    CPen* pYellow;      // 黄色画笔
    CPen* pGren;        // 绿色画笔
    CPen* pPink;        // 紫色画笔
    CPen* pRed;         // 红色画笔
    CPen* pGray;        // 灰色画笔  

    CRect Draw_Size;
    CDC memDC;
    CBitmap memBitmap;
    CBitmap* pOldBmp;  

    unsigned short SheetMaxH;  

    CWnd *pWnd;  

    void Draw();
    void Drawing(CDC *pDC);       // 绘制图表
    void Draw_xAxis(CDC *pDC);
    void Draw_yAxis(CDC *pDC);
    void Draw_Cross_Cursor(CDC *pDC);  

    void My_Draw::SaveBmpToFile();
protected:  

    afx_msg void OnLButtonDown(UINT nFlags, CPoint point);
    afx_msg void OnMouseMove(UINT nFlags, CPoint point);
    afx_msg void OnLButtonUp(UINT nFlags, CPoint point);
    afx_msg void OnLButtonDblClk(UINT nFlags, CPoint point);
    DECLARE_MESSAGE_MAP()
}; 

// .CPP 文件中：

#include "stdafx.h"
#include "Draw_Static_Text.h"
#include "conio.h"
#include "direct.h"  

#ifdef _DEBUG
#define new DEBUG_NEW
#endif  

// 构造函数
My_Draw::My_Draw()
{
    Bool_Flag.Show_Max_Grid = false;
    Bool_Flag.Show_Min_Grid = false;
    Bool_Flag.Draw_Enable = false;
    Bool_Flag.Draw_Line_Choice = false;
    Bool_Flag.LButton_Down_Flag = false;
    Bool_Flag.LButton_Up_Flag = false;
    Bool_Flag.LButton_Double_Down_Flag = false;  

    TextAreaWidth = TEXT_AREA_WIDTH;
    xAxisGrad = X_AXIS_GRAD;
    yAxisGrad = Y_AXIS_GRAD;  

    pBrack = new CPen();        // 黑色画笔
    pBlue = new CPen();         // 蓝色画笔
    pYellow = new CPen();       // 黄色画笔
    pGren = new CPen();         // 绿色画笔
    pRed = new CPen();          // 红色画笔
    pPink = new CPen();         // 紫色画笔
    pGray = new CPen();         // 灰色画笔  

    pBrack->CreatePen(PS_SOLID,,RGB(,,));
    pBlue->CreatePen(PS_SOLID,,RGB(,,));
    pYellow->CreatePen(PS_SOLID,,RGB(,,));
    pGren->CreatePen(PS_SOLID,,RGB(,,));
    pRed->CreatePen(PS_SOLID,,RGB(,,));
    pPink->CreatePen(PS_SOLID,,RGB(,,));
    pGray->CreatePen(PS_DOT,,RGB(,,));  

#ifdef _DEBUG
    AllocConsole();
    _cprintf("Debuging....\r\n");
#endif
}  

// 析构函数
My_Draw::~My_Draw()
{
    delete pBrack;        // 黑色画笔
    delete pBlue;         // 蓝色画笔
    delete pYellow;       // 黄色画笔
    delete pGren;         // 绿色画笔
    delete pRed;          // 红色画笔
    delete pPink;         // 紫色画笔
    delete pGray;         // 灰色画笔
}  

BEGIN_MESSAGE_MAP(My_Draw, CStatic)
    ON_WM_LBUTTONDOWN()
    ON_WM_MOUSEMOVE()
    ON_WM_LBUTTONUP()
    ON_WM_LBUTTONDBLCLK()
END_MESSAGE_MAP()  

void My_Draw::SaveBmpToFile()       // 保存图表为 Bmp 图片
{
    CFileDialog dlg(false,NULL,NULL,OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,
        "位图文件(*.bmp)|*.bmp|",NULL);  

    if (dlg.DoModal()!= IDOK) return;
    CString filename = dlg.GetFileName() + ".bmp";  

    // 获取绘制坐标的文本框
    this->GetClientRect(&Draw_Size);    // 获取窗口大小
    CDC *pDC = this->GetDC();     // 获取 dc
    this->Invalidate();
 this->UpdateWindow();  

    //内存绘图
    memDC.CreateCompatibleDC(pDC);
    memBitmap.CreateCompatibleBitmap(pDC,Draw_Size.right,Draw_Size.bottom);
    pOldBmp = memDC.SelectObject(&memBitmap);
    memDC.BitBlt(Draw_Size.left,Draw_Size.top,Draw_Size.right,Draw_Size.bottom,pDC,,,SRCCOPY);
    Drawing(&memDC);       // 绘制坐标  

    BITMAP bmp;
    memBitmap.GetBitmap(&bmp);                                               // 获得位图信息
    FILE *fp;
    fopen_s(&fp,filename, "w+b");
    BITMAPINFOHEADER bih = {};                                              // 位图信息头
    bih.biBitCount = bmp.bmBitsPixel;                                        // 每个像素字节大小
    bih.biCompression = BI_RGB;
    bih.biHeight = bmp.bmHeight;                                             // 高度
    bih.biPlanes = ;
    bih.biSize = sizeof(BITMAPINFOHEADER);
    bih.biSizeImage = bmp.bmWidthBytes * bmp.bmHeight;                       // 图像数据大小
    bih.biWidth = bmp.bmWidth;                                               // 宽度
    BITMAPFILEHEADER bfh = {};                                              // 位图文件头
    bfh.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);     // 到位图数据的偏移量
    bfh.bfSize = bfh.bfOffBits + bmp.bmWidthBytes * bmp.bmHeight;            // 文件总的大小
    bfh.bfType = (WORD)0x4d42;
    fwrite(&bfh, , sizeof(BITMAPFILEHEADER), fp);                           // 写入位图文件头
    fwrite(&bih, , sizeof(BITMAPINFOHEADER), fp);                           // 写入位图信息头
    byte * p = new byte[bmp.bmWidthBytes * bmp.bmHeight];                    // 申请内存保存位图数据
    GetDIBits(memDC.m_hDC, (HBITMAP) memBitmap.m_hObject, , Draw_Size.Height(), p,  (LPBITMAPINFO) &bih, DIB_RGB_COLORS);                                    //获取位图数据
    fwrite(p, , bmp.bmWidthBytes * bmp.bmHeight, fp);                       // 写入位图数据
    delete [] p;
    fclose(fp);  

    memDC.SelectObject(pOldBmp);
    memDC.DeleteDC();                                                       // 释放 Dc
    memBitmap.DeleteObject();
}  

void My_Draw::Draw()
{
    this->Invalidate();
 this->UpdateWindow();
    this->GetClientRect(&Draw_Size);    // 获取窗口大小
    CDC *pDC = this->GetDC();     // 获取 dc
    //内存绘图
    memDC.CreateCompatibleDC(pDC);
    memBitmap.CreateCompatibleBitmap(pDC,Draw_Size.right,Draw_Size.bottom);
    pOldBmp = memDC.SelectObject(&memBitmap);
    memDC.BitBlt(Draw_Size.left,Draw_Size.top,Draw_Size.right,Draw_Size.bottom,pDC,,,SRCCOPY);
    Drawing(&memDC);       // 绘制坐标
    pDC->BitBlt(Draw_Size.left,Draw_Size.top,Draw_Size.right,Draw_Size.bottom,&memDC,,,SRCCOPY);  

    memDC.SelectObject(pOldBmp);
    memDC.DeleteDC();
    memBitmap.DeleteObject();  

    ReleaseDC(pDC);
}  

void My_Draw::Drawing(CDC *pDC)
{
    pDC->SelectObject(pBrack);                         // 选择当前画笔颜色
    pDC->Rectangle(,,Draw_Size.Width(),Draw_Size.Height());       // 设定绘制范围  

    //绘出文字  

 pDC->SetTextColor(RGB(,,));
 pDC->SetBkMode(TRANSPARENT);
 pDC->TextOutA(,,"输");
 pDC->TextOutA(,,"出");
 pDC->TextOutA(,,"电");
 pDC->TextOutA(,,"压");
 pDC->TextOutA(,,"|");
 pDC->TextOutA(,,"单");
 pDC->TextOutA(,,"位");
 pDC->TextOutA(,,"(V)");  

 pDC->TextOutA(Draw_Size.Width()/-,Draw_Size.Height()-,"行    程--单位 (%)");  

    SheetMaxH = Draw_Size.Height()-TextAreaWidth;  

    Draw_xAxis(pDC);
    Draw_yAxis(pDC);
    Draw_Cross_Cursor(pDC);  

    ReleaseDC(pDC);
}  

void My_Draw::Draw_xAxis(CDC *pDC)
{
    CString StrScale;           // 转换刻度字符串存放点
    unsigned short drawCount;   // 画王格计数
    unsigned short temp;
    unsigned int girdSize;  

    //绘制x轴坐标
 pDC->MoveTo(TextAreaWidth,SheetMaxH);
 pDC->LineTo(Draw_Size.Width(),SheetMaxH);
 //绘制箭头
 pDC->LineTo(Draw_Size.Width()-,SheetMaxH-);
 pDC->MoveTo(Draw_Size.Width(),SheetMaxH);
 pDC->LineTo(Draw_Size.Width()-,SheetMaxH+);  

    //绘制x轴刻度
 drawCount = ;
 if(xAxisGrad > Draw_Size.Width())
 {
  xAxisGrad/=;
  girdSize = ;
 }
 else
  girdSize = ;  

 xMaxGrad = int((Draw_Size.Width() - TextAreaWidth) / xAxisGrad);
 for(int i=TextAreaWidth; i<=Draw_Size.Width(); i+=xMaxGrad)
 {
  pDC->SelectObject(pBrack);
  pDC->MoveTo(i,SheetMaxH);
  if(xMaxGrad<)
   temp = xMaxGrad*;
  else
   temp = xMaxGrad*;
  if((i-TextAreaWidth)%temp==)
  {
   pDC->LineTo(i,SheetMaxH+);                            // 整数刻度，绘制长刻度  

   //输出对应的文本
   if(drawCount < )
   {
    //pDC->SelectObject(font1);                         //选择当前字体
    StrScale.Format(" %d", drawCount*girdSize);
    pDC->SetTextColor(RGB(, , ));
    pDC->TextOutA(i-, SheetMaxH+, StrScale);          //修正文本显示坐标  3位数内，显示方式  

                if(Bool_Flag.Show_Max_Grid)
                {
                    pDC->SelectObject(pGray);                       //使用虚线灰色画笔
                    pDC->MoveTo(i,SheetMaxH);
                    pDC->LineTo(i,);
                }
   }
   else
   {
    StrScale.Format(" %d", drawCount*girdSize);
    pDC->TextOutA(i-, SheetMaxH+, StrScale);          //修正文本显示坐标  4位数内，显示方式  

                if(Bool_Flag.Show_Max_Grid)
                {
                    pDC->SelectObject(pGray);                       //使用虚线灰色画笔
                    pDC->MoveTo(i, SheetMaxH);
                    pDC->LineTo(i, );
                }
   }
  }
  else
  {
   pDC->LineTo(i,SheetMaxH+);                             //小数刻度，绘制短刻度
  }
  drawCount++;
 }  

    ReleaseDC(pDC);
}  

void My_Draw::Draw_yAxis(CDC *pDC)
{
    unsigned int drawCount;
 CString StrScale;     //转换刻度字符串存放点  

    drawCount = ;
    //绘制y轴坐标
 pDC->MoveTo(TextAreaWidth, SheetMaxH);
 pDC->LineTo(TextAreaWidth, );
 //绘制箭头
 pDC->LineTo(TextAreaWidth-, );
 pDC->MoveTo(TextAreaWidth, );
 pDC->LineTo(TextAreaWidth+, );  

 yMaxGrad = int(SheetMaxH / yAxisGrad);
 for(int i=SheetMaxH; i>=; i-=yMaxGrad)
 {
        pDC->SelectObject(pBrack);
  StrScale.Format("%d", drawCount / );
  pDC->MoveTo(TextAreaWidth, i);  

  if(drawCount % ==)
  {
   pDC->LineTo(TextAreaWidth-, i);                        //整数刻度，绘制长刻度  

            if(Bool_Flag.Show_Max_Grid)
            {
                pDC->SelectObject(pGray);                           //使用实线灰色画笔
                pDC->MoveTo(TextAreaWidth, i);
                pDC->LineTo(Draw_Size.Width()-, i);
            }  

   pDC->SetTextColor(RGB(, , ));
   pDC->TextOutA(TextAreaWidth-, i-, StrScale+"V");       //输出对应的文本
  }
  else
  {
   pDC->LineTo(TextAreaWidth-, i);                         //小数刻度，绘制短刻度
  }
  drawCount++;
 }  

    ReleaseDC(pDC);
}  

void My_Draw::Draw_Cross_Cursor(CDC *pDC)
{
    int m_intVoltage;
    int m_intAngle;  

    // 十字光标和显示坐标信息
    if(Bool_Flag.LButton_Double_Down_Flag)
    {
        if((LButton_Double_Down_Point.x > TextAreaWidth)
            &&(LButton_Double_Down_Point.x < Draw_Size.Width())
            &&(LButton_Double_Down_Point.y > )
            &&(LButton_Double_Down_Point.y < SheetMaxH))
        {
            if(Bool_Flag.Draw_Line_Choice)
                pDC->SelectObject(pGren);
            else
                pDC->SelectObject(pRed);  

            pDC->MoveTo(LButton_Double_Down_Point.x, );
            pDC->LineTo(LButton_Double_Down_Point.x, SheetMaxH-);  

            pDC->MoveTo(TextAreaWidth+, LButton_Double_Down_Point.y);
            pDC->LineTo(Draw_Size.Width()-,LButton_Double_Down_Point.y);  

            Old_LButton_Double_Down_Point = LButton_Double_Down_Point;  

            m_intVoltage = yAxisGrad;
            m_intVoltage = (SheetMaxH - LButton_Double_Down_Point.y)/m_intVoltage;
            m_intVoltage /= ;
            m_intAngle = xAxisGrad;
            m_intAngle = (LButton_Double_Down_Point.x - TextAreaWidth)/m_intAngle;
#ifdef _DEBUG
            _cprintf("Voltage = %0.2f,Angle = %0.2f\r\n",xAxisGrad,m_intAngle);
#endif
            UpdateData(FALSE);
        }
    }  

    if(Bool_Flag.LButton_Down_Flag)
    {
        pDC->SelectObject(pBrack);
        pDC->MoveTo(Button_Down_Point);
        pDC->LineTo(Mouse_Current_Point.x,Button_Down_Point.y);  

        pDC->MoveTo(Mouse_Current_Point.x,Button_Down_Point.y);
        pDC->LineTo(Mouse_Current_Point);  

        pDC->MoveTo(Mouse_Current_Point);
        pDC->LineTo(Button_Down_Point.x,Mouse_Current_Point.y);  

        pDC->MoveTo(Button_Down_Point.x,Mouse_Current_Point.y);
        pDC->LineTo(Button_Down_Point);  

    }
    ReleaseDC(pDC);
}  

void My_Draw::OnMouseMove(UINT nFlags, CPoint point)
{
    // TODO: 在此添加消息处理程序代码和/或调用默认值
    Mouse_Current_Point = point;  

    if(Bool_Flag.Draw_Line_Choice)
    {
        Limit_Min = point.x - ;
        Limit_Max = point.x + ;
        LButton_Double_Down_Point = point;
    }  

    if((Bool_Flag.LButton_Down_Flag)
    ||(Bool_Flag.LButton_Up_Flag))
        Draw();  

    CStatic::OnMouseMove(nFlags, point);
}  

void My_Draw::OnLButtonDown(UINT nFlags, CPoint point)
{
    // TODO: 在此添加消息处理程序代码和/或调用默认值
    if((Bool_Flag.LButton_Double_Down_Flag)
        &&(point.x >= Limit_Min)
        &&(point.x <= Limit_Max))
    {
        if(Bool_Flag.Draw_Line_Choice)
            Bool_Flag.Draw_Line_Choice = FALSE;
        else
            Bool_Flag.Draw_Line_Choice = TRUE;  

        LButton_Double_Down_Point = point;
    }
    else
    {
        if((Bool_Flag.LButton_Down_Flag == FALSE)
            &&(Bool_Flag.Draw_Line_Choice == FALSE))
        {
            Bool_Flag.LButton_Down_Flag = true;
            Button_Down_Point = point;
        }
    }
    Draw();  

    CStatic::OnLButtonDown(nFlags, point);
}  

void My_Draw::OnLButtonUp(UINT nFlags, CPoint point)
{
    // TODO: 在此添加消息处理程序代码和/或调用默认值
    if(Bool_Flag.LButton_Down_Flag)
    {
        Bool_Flag.LButton_Up_Flag = true;
        Bool_Flag.LButton_Down_Flag = FALSE;
        Draw();
    }  

    CStatic::OnLButtonUp(nFlags, point);
}  

void My_Draw::OnLButtonDblClk(UINT nFlags, CPoint point)
{
    // TODO: 在此添加消息处理程序代码和/或调用默认值  

    LButton_Double_Down_Point = point;  

    Limit_Min = LButton_Double_Down_Point.x - ;
    Limit_Max = LButton_Double_Down_Point.x + ;  

    Bool_Flag.LButton_Double_Down_Flag = TRUE;
    Draw();  

    CStatic::OnLButtonDblClk(nFlags, point);
}  

程序运行效果图

现在说明一下

1.  新建一个 MFC 应用程序

2. 选择“基于对话框”

3. 添加一个 “Picture 控件”

4. 为控件添加一个变量 my_Graw

5. 将源文件包含进来，并在 My_ClassDlg.h 中包含 #include "My Draw.h"

6. 在 My_ClassDlg.h 头文件中将刚才声明的 Picture  控件变量 CStatic my_Graw ; 改成  My_Draw my_Graw;

7. 在 My_ClassDlg.cpp 文件 void CMy_ClassDlg::OnPaint() 尾部添加 my_Graw.Draw();

8. 编译运行

读者可根据自己的需要在响应的地方改下就好了。
示例下载 http://download.csdn.net/detail/longzhishen/7227255