MFC繪制直角坐標系

void CMyPicoTestDlg::DrawWave(CDC *pDC,CRect &rectPicture)
{

    CPen newPen;                  //用於創建新畫筆
    CPen *pOldPen;                  //用於存放舊畫筆
    CBrush newBrush;              //用於創建新畫筆
    CBrush *pOldBrush;            //用於存放舊畫筆        
        newBrush.CreateSolidBrush(RGB(0,0,0));    //新建黑色畫刷
    pOldBrush=pDC->SelectObject(&newBrush); //選擇新畫刷並將舊畫刷的指針保存在pOldBrush
    pDC->Rectangle(rectPicture); //黑色畫刷為繪圖控件，形成黑色背景
    pDC->SelectObject(pOldBrush);//恢復舊畫刷
    newBrush.DeleteObject(); //刪除新畫刷

    newPen.CreatePen(PS_SOLID,1,RGB(0,255,0));  //創建實心畫筆，粗度為1，顏色為綠色
    pOldPen=pDC->SelectObject(&newPen);//選擇新畫筆，並將舊畫筆的指針保存在pOldPen
/************************************************************************/
/* 坐標軸                                                               */
/************************************************************************/
//x軸
    pDC->MoveTo(0,rectPicture.Height()/2);
    pDC->LineTo(rectPicture.Width(),rectPicture.Height()/2);
//y軸
    pDC->MoveTo(rectPicture.Width()/2,0);
    pDC->LineTo(rectPicture.Width()/2,rectPicture.Height());
//x軸刻度
    
    for (int32_t i=rectPicture.Width()/2-10;i>0;i-=10)
    {
        pDC->MoveTo(i,rectPicture.Height()/2);
        pDC->LineTo(i,rectPicture.Height()/2-5);
    }
    for (int32_t i=rectPicture.Width()/2+10;i<rectPicture.Width()+1;i+=10)
    {
        pDC->MoveTo(i,rectPicture.Height()/2);
        pDC->LineTo(i,rectPicture.Height()/2-5);

    }
//y軸刻度
    for (int32_t i=rectPicture.Height()/2-10;i>0;i-=10)
    {
        pDC->MoveTo(rectPicture.Width()/2,i);
        pDC->LineTo(rectPicture.Width()/2+5,i);
    }
    for (int32_t     
         i=rectPicture.Height()/2+10;i<rectPicture.Height();i+=10)
    {
        pDC->MoveTo(rectPicture.Width()/2,i);
        pDC->LineTo(rectPicture.Width()/2+5,i);
    }
    pDC->SelectObject(pOldPen);//恢復舊畫筆
    newPen.DeleteObject();//刪除新畫筆
 }

調用

void CMyPicoTestDlg::OnBnClickedButton2()
{
    // TODO: 在此添加控件通知處理程序代碼
    
    CRect rectPicture;   
    m_picDraw.GetClientRect(&rectPicture);   
       //繪制坐標系
    DrawWave(m_picDraw.GetDC(), rectPicture);

}