//        绘制外圆
        hp=CreatePen(PS_SOLID,1,RGB(255,0,255));
        SelectObject(hdc,hp);
        Ellipse(hdc,-100,-100,100,100);

//        绘制风车的叶片
//        绘制红色的叶片
        hBrush=CreateSolidBrush(RGB(255,0,0));
        SelectObject(hdc,hBrush);
        fAngle=2*PI/nMaxNum*nNum;
        nCenterX=(int)(50*cos(fAngle));
        nCenterY=(int)(50*sin(fAngle));
        Pie(hdc,nCenterX-50,nCenterY-50,nCenterX+50,nCenterY+50,(int)(nCenterX+50*cos(fAngle)),(int)(nCenterY+50*sin(fAngle)),(int)(nCenterX+50*cos(fAngle+PI)),(int)(nCenterY+50*sin(fAngle+PI)));

//        绘制蓝色的叶片
        hBrush=CreateSolidBrush(RGB(255,255,0));
        SelectObject(hdc,hBrush);
        nCenterX=(int)(50*cos(fAngle+2*PI/3));
        nCenterY=(int)(50*sin(fAngle+2*PI/3));
        Pie(hdc,nCenterX-50,nCenterY-50,nCenterX+50,nCenterY+50,(int)(nCenterX+50*cos(fAngle+2*PI/3)),(int)(nCenterY+50*sin(fAngle+2*PI/3)),(int)(nCenterX+50*cos(fAngle+PI+2*PI/3)),(int)(nCenterY+50*sin(fAngle+PI+2*PI/3)));
        
//        绘制黄色的叶片
        hBrush=CreateSolidBrush(RGB(0,255,255));
        SelectObject(hdc,hBrush);
        nCenterX=(int)(50*cos(fAngle+4*PI/3));
        nCenterY=(int)(50*sin(fAngle+4*PI/3));
        Pie(hdc,nCenterX-50,nCenterY-50,nCenterX+50,nCenterY+50,(int)(nCenterX+50*cos(fAngle+4*PI/3)),(int)(nCenterY+50*sin(fAngle+4*PI/3)),(int)(nCenterX+50*cos(fAngle+PI+4*PI/3)),(int)(nCenterY+50*sin(fAngle+PI+4*PI/3)));

        nNum++;
        Sleep(100);
        InvalidateRect(hwnd,NULL,1);
        EndPaint(hwnd,&ps);

        return 0;
    case WM_CLOSE:
        PostQuitMessage(0);