1.　paint函式，void CDemo_ShowRouteDlg::paint(CPoint point, double i_Scale, int i_num)。呼叫：paint(Point_Bitmap, i_scale, 2);

2.CPoint類。見百度百科。

3.CPaintDC。當前視窗作圖。https://blog.csdn.net/liuy_yy/article/details/7192567

4.CRect。矩形類，見百度百科

5.GetClientRect(&rect);  該函式獲取視窗客戶區的大小。

6.第一個點在左側中間，第二個點在右側中間，第三個點在上部中間，第四個點在下部中間

	CPoint oPt1;
	oPt1.x=30 - 3;
	oPt1.y=20 + ylong / 2;
	CPoint xPt1;
	xPt1.x=30 + xlong + 3;
	xPt1.y=20 + ylong / 2;
	CPoint yPt1;
	yPt1.x=30 + xlong / 2;
	yPt1.y=20 - 3;
	CPoint yPt2;
	yPt2.x=30 + xlong / 2;
	yPt2.y=20 + ylong + 3;

7.Pen pen(Color(50,80,40,40), 20.0f);（分別是顏色，寬度）其中color的四個引數如下：

    static ARGB MakeARGB(IN BYTE a,
                         IN BYTE r,
                         IN BYTE g,
                         IN BYTE b)
    {
        return (((ARGB) (b) <<  BlueShift) |
                ((ARGB) (g) << GreenShift) |
                ((ARGB) (r) <<   RedShift) |
                ((ARGB) (a) << AlphaShift));
    }
8.SolidBrush b_Brush(Color(50, 80, 20, 30));建立固體刷
9.GraphicsPath　　繪圖路徑　　
 
https://docs.microsoft.com/zh-cn/dotnet/api/system.drawing.drawing2d.graphicspath.-ctor?redirectedfrom=MSDN&view=netframework-4.7.2#System_Drawing_Drawing2D_GraphicsPath__ctor
10.PointF CenterPoint;    //三角形中心點。浮點型的點

class PointF
{
public:
   PointF()
   {
       X = Y = 0.0f;
   }
}

11.Bitmap點陣圖資料。

12.Graphics　　https://blog.csdn.net/hireboy/article/details/8989997

13.Direction(m_PrePoint, CenterPoint, pp);　　原函式：PointF* CDemo_ShowRouteDlg::Direction(PointF p0, PointF p1, PointF* point)

14.memDC.FillPolygon(&b_Brush, pp, 4); 填充多邊形

15.DrawImage

16.Invalidate( ) ：使整個視窗客戶區無效, 並進行更新顯示的函式