从一个舆论调查的制作谈面向对象的编程思路（四）-.NET教程,Asp.Net开发

        public mychart()
        {
            //
            // todo: add constructor logic here
            //
            m_arritems = new arraylist() ;
            m_strtitle = "" ;
            m_objbackcolor = color.white ;
            m_intwidth = 200 ;
            m_intheight = 200 ;
            m_intcharttype = charttype.pie ;
            m_strunit = "" ;
        }

        /// <summary>
        /// 重载构造函数
        /// </summary>
        /// <param name="a_strtitle"> </param>
        /// <param name="a_objbackcolor"> </param>
        /// <param name="a_intwidth"> </param>
        /// <param name="a_intheight"> </param>
        /// <param name="a_intcharttype"> </param>
        /// <param name="a_strunit"> </param>
        public mychart(string a_strtitle , system.drawing.color a_objbackcolor ,
                        int a_intwidth , int a_intheight , charttype  a_intcharttype , string a_strunit)
        {
            m_arritems = new arraylist() ;
            m_strtitle = a_strtitle ;
            m_objbackcolor = a_objbackcolor ;
            m_intwidth = a_intwidth ;
            m_intheight = a_intheight ;
            m_intcharttype = a_intcharttype ;
            m_inttotalcount = 0 ;
            m_strunit = a_strunit ;
        }

        /// <summary>
        /// 添加一个新的统计图项目
        /// </summary>
        /// <param name="a_objitem"> </param>
        public void additem(object a_objitem)
        {
            if(a_objitem is myclass.util.chartitem)
            {
                m_arritems.add(a_objitem) ;
                m_inttotalcount += ((chartitem)a_objitem).count ;
            }
            else
            {
                throw(new exception("对象类型错误，要加入的必须是chartitem对象")) ;
            }
        }

        /// <summary>
        /// 产生统计图图片
        /// </summary>
        /// <param name="a_strfilename">要保存的文件名 </param>
        /// <remarks>
        ///  a_strfilename必须是绝对物理路径
        /// </remarks>
        public void create(string a_strfilename)
        {
            //如果没有定义统计图项，则抛出异常
            if (m_arritems.count == 0)
            {
                throw(new exception("没有定义统计图项")) ;
            }

            //根据不同统计图类型选择函数
            switch(m_intcharttype)
            {
                case charttype.bar:
                    drawbar(a_strfilename) ;
                    break;

                case charttype.pie:
                    drawpie(a_strfilename) ;
                    break ;

                case charttype.curve:
                    drawcurve(a_strfilename) ;
                    break ;

                default:
                    drawpie(a_strfilename) ;
                    break ;
            }

        }

        /// <summary>
        /// 画条形图
        /// </summary>
        /// <param name="a_strfilename">要保存的图片名称</param>
        protected void drawbar(string a_strfilename)
        {
            //绘图准备，新建一个image对象,一个graphics对象
            system.drawing.image mybmp = new bitmap(m_intwidth , m_intheight ) ;
            system.drawing.graphics g = graphics.fromimage(mybmp) ;

            //填充背景
            g.fillrectangle(new system.drawing.solidbrush(m_objbackcolor) , 0 , 0 , m_intwidth , m_intheight) ;

            //如果没有任何回答，则显示没有结果
            if (this.m_inttotalcount == 0)
            {
                g.drawstring("没有统计数字！" , new font("宋体" , m_intwidth / 14) ,
                        new solidbrush(color.red) , (m_intwidth – m_intwidth / 8 * 6) / 2 ,
                        m_intheight / 2 – m_intwidth / 8) ;
            }
            else
            {
            
                //写题目

                //g.drawstring(m_strtitle , new system.drawing.font("黑体" , m_intwidth / 30) ,
                //        new system.drawing.solidbrush(color.black) , (m_intwidth – m_strtitle.length * (m_intwidth / 30))/2  , 10 ,
                //        system.drawing.stringformat.genericdefault) ;

                //画统计图项目的矩形
                //计算每个矩形的宽度
                int intwidth = m_intwidth / (m_arritems.count * 2 – 1) ;

                //定义一个一个像素宽的黑色的笔
                system.drawing.pen pen = new system.drawing.pen(new system.drawing.solidbrush(color.black) , 1) ;

                for (int i = 0 ; i < m_arritems.count ; i ++)
                {
                    chartitem item = (chartitem)m_arritems[i] ;

                    //计算所占百分比
                    float intpercent = (float)decimal.divide(item.count * 100 , m_inttotalcount) ;

                    //计算矩形高度
                    int intheight = (int)(m_intheight/ 3 * 2 * intpercent / 100 – 10) ;

                    //计算矩形坐标
                    int ix = intwidth * i * 3 / 2 + intwidth ;
                    int iy = m_intheight /  3 * 2  – intheight ;

                    //画矩形
                    g.fillrectangle(new system.drawing.solidbrush(item.color) ,
                                    ix , iy , intwidth , intheight + 10) ;

                    //写字
                    //计算字体大小
                    int intfontsize = intwidth / this.totalcount.tostring().length ;
                    //限制一下，字体大小不能超过12
                    intfontsize = intfontsize > 12 ? 12 : intfontsize ;
                    g.drawstring(item.count.tostring() + m_strunit ,
                                new system.drawing.font("宋体" , intfontsize) ,
                                new system.drawing.solidbrush(item.color) ,
                                ix , iy – intfontsize * 2) ;

                    //画图例

                    //计算字体大小
                    intfontsize = m_intheight / 3 / m_arritems.count / 2 – 1 ;
                    intfontsize = intfontsize > 12 ? 12 : intfontsize ;
                    g.fillrectangle(new system.drawing.solidbrush(item.color) , 20 ,
                                    m_intheight / 3 * 2 + intfontsize * (i * 2 + 1) + 5 ,
                                    intfontsize , intfontsize) ;
                    g.drawstring( intpercent.toint32().tostring() + "%" ,
                                    new system.drawing.font("宋体" , intfontsize) ,
                                    new system.drawing.solidbrush(item.color) ,
                                    20 + intfontsize ,
                                    m_intheight /  3 * 2 + intfontsize * (i * 2 + 1) + 5) ;
                    g.drawstring(item.text  ,
                                    new system.drawing.font("宋体" , intfontsize) ,
                                    new system.drawing.solidbrush(item.color) , 80 ,
                                    m_intheight / 3 * 2 + intfontsize * (i * 2 + 1) + 5) ;
                
                }

                //画标志线
                g.drawline(pen , 0 , 10 , 0 , m_intheight / 3 * 2 + 10) ;
                g.drawline(pen , 0 , m_intheight / 3 * 2 + 10 , m_intwidth ,
                            m_intheight / 3 * 2 + 10) ;
                for (int i = 0 ; i < 10 ; i++)
                {
                    g.drawline( pen , 0 , m_intheight / 3 * 2 / 10 * i + 10 ,
                                5 , m_intheight / 3 * 2 / 10 * i + 10) ;
                }

                //写单位
                //g.drawstring("单位：" + m_strunit , new system.drawing.font("宋体" , m_intwidth/40) ,
                //        new solidbrush(color.black) , 10 , 10) ;

                //清空
                pen.dispose() ;
            }

            //清控对象
            g.dispose() ;

            //保存为jpg格式
            try
            {
                mybmp.save(a_strfilename , system.drawing.imaging.imageformat.jpeg) ;
            }
            catch(exception e)
            {
                throw(new exception("保存图片失败:" + e.tostring())) ;
            }

            mybmp.dispose() ;
            
        }

        /// <summary>
        /// 画饼形图
        /// </summary>
        /// <param name="a_strfilename"> </param>
        /// <remarks>
        /// 这段程序很难懂，因为需要根据图片大小决定饼图及文字的大小，所以所有计算方法
        /// 都是试验出来的。
        /// </remarks>
        protected void drawpie(string a_strfilename)
        {
            //绘图准备，新建一个image对象,一个graphics对象
            system.drawing.image mybmp = new bitmap(m_intwidth , m_intheight ) ;
            system.drawing.graphics g = graphics.fromimage(mybmp) ;

            //填充背景
            g.fillrectangle(new system.drawing.solidbrush(m_objbackcolor) , 0 , 0 , m_intwidth , m_intheight) ;

            //如果没有任何回答，则显示没有结果
            if (this.m_inttotalcount == 0)
            {
                g.drawstring("没有统计数字！" , new font("宋体" , m_intwidth / 14) ,
                        new solidbrush(color.red) , (m_intwidth – m_intwidth / 8 * 6) / 2 ,
                        m_intheight / 2 – m_intwidth / 8) ;
            }
            else
            {
                //定义一个浮点变量，记住上一个项目结束的角度
                int intangel = 180 ;
            
                //画饼形图
                for (int i = 0 ; i < m_arritems.count ; i ++)
                {
                    chartitem item = (chartitem)m_arritems[i] ;

                    //开始时从180度开始

                    //计算所占百分比
                    float intpercent = (float)decimal.divide(item.count * 100 , m_inttotalcount) ;
                    if (i == m_arritems.count – 1)
                    {
                        g.fillpie(new solidbrush(item.color) , 0 , 0 , m_intwidth * 2 / 3 ,
                                m_intheight * 2 / 3 , intangel , 540 – intangel) ;
                    }
                    else
                    {
                        g.fillpie(new solidbrush(item.color) , 0 , 0 , m_intwidth * 2 / 3,
                                m_intheight * 2 / 3 , intangel , 360 * intpercent/100) ;
                        intangel += (int)(360 * intpercent/100) ;
                    }

                    //画饼图右边图例百分数
                    //计算矩形大小
                    int intrectsize = m_intheight / 30 ;

                    //画颜色方块
                    g.fillrectangle(new solidbrush(item.color) , m_intwidth * 2 / 3 + intrectsize ,
                        intrectsize * (i * 2 + 1) + m_intheight / 2 – m_arritems.count * 2 * intrectsize
                        ,intrectsize , intrectsize) ;  

                    //写百分数
                    g.drawstring(item.count.tostring() + m_strunit ,
                            new font("宋体" , intrectsize) ,
                            new solidbrush(item.color) ,
                            m_intwidth * 2 / 3 + intrectsize * 3 ,
                            intrectsize * (i * 2 + 1) + m_intheight / 2
                            – m_arritems.count * 2 * intrectsize);

                    //画饼图下方图例文字
                    //计算矩形大小
                    intrectsize = m_intheight / 3 / (m_arritems.count * 2) – 1 ;
                    intrectsize = intrectsize > 12 ? 12 : intrectsize ;

                    //画颜色方块
                    g.fillrectangle(new solidbrush(item.color) , intrectsize * 2 ,
                        intrectsize * (i * 2 + 1) + m_intheight / 3 * 2  
                        ,intrectsize , intrectsize) ;  
                    //写文字
                    g.drawstring(intpercent.toint32().tostring() + "%  " + item.text ,
                                new font("宋体" , intrectsize) ,
                                new solidbrush(item.color) , intrectsize * 4 ,
                                intrectsize * ( i * 2 + 1) + m_intheight / 3 * 2) ;
                
                }
            }
            //清控对象
            g.dispose() ;

            //保存为jpg格式
            try
            {
                mybmp.save(a_strfilename , system.drawing.imaging.imageformat.jpeg) ;
            }
            catch(exception e)
            {
                throw(new exception("保存图片失败:" + e.tostring())) ;
            }

            mybmp.dispose() ;

        }

        /// <summary>
        /// 画折线图
        /// </summary>
        /// <param name="a_strfilename"> </param>
        protected void drawcurve(string a_strfilename)
        {
            //绘图准备，新建一个image对象,一个graphics对象
            system.drawing.image mybmp = new bitmap(m_intwidth , m_intheight ) ;
            system.drawing.graphics g = graphics.fromimage(mybmp) ;

            //填充背景
            g.fillrectangle(new system.drawing.solidbrush(m_objbackcolor) , 0 , 0 , m_intwidth , m_intheight) ;

            //如果没有任何回答，则显示没有结果
            if (this.m_inttotalcount == 0)
            {
                g.drawstring("没有统计数字！" , new font("宋体" , m_intwidth / 14) ,
                        new solidbrush(color.red) , (m_intwidth – m_intwidth / 8 * 6) / 2 ,
                        m_intheight / 2 – m_intwidth / 8) ;
            }
            else
            {
                //定义一个一个像素宽的黑色的笔
                system.drawing.pen pen = new system.drawing.pen(new system.drawing.solidbrush(color.black) , 1) ;
            
                //画标志线
                g.drawline(pen , 0 , 10 , 0 , m_intheight / 3 * 2 + 10) ;
                g.drawline(pen , 0 , m_intheight / 3 * 2 + 10 , m_intwidth , m_intheight / 3 * 2 + 10) ;
                for (int i = 0 ; i < 10 ; i++)
                {
                    g.drawline( pen , 0 , m_intheight / 3 * 2 / 10 * i + 10 , 5 , m_intheight / 3 * 2 / 10 * i + 10) ;
                }

                //写单位
                g.drawstring("单位：" + m_strunit , new system.drawing.font("宋体" , m_intwidth/40) ,
                        new solidbrush(color.black) , 10 , 10) ;

                //画折线

                //计算宽度
                int intwidth = m_intwidth / (m_arritems.count * 2) ;

                //定义两个变量，记住上一个点的x , y
                int ix = 0 ;
                int iy = 0 ;

                for ( int i = 0 ; i < m_arritems.count ; i ++)
                {
                    chartitem item = (chartitem)m_arritems[i] ;

                    //计算所占百分比
                    float intpercent = (float)decimal.divide(item.count * 100 , m_inttotalcount) ;

                    //计算点高度
                    int intheight = (int)(m_intheight / 3 * 2 * intpercent / 100) ;

                    //画点
                    g.fillellipse(new solidbrush(item.color) , intwidth * (i * 2 + 1) ,
                        m_intheight / 3 * 2 – intheight , 10 , 10) ;
                
                    //连接线
                    //定义笔，如果是升则为蓝颜色，否则是红色
                    if (iy > m_intheight /3 * 2 – intheight + 5)
                    {
                        pen = new pen(new solidbrush(color.blue) , 3) ;
                    }
                    else
                    {
                        pen = new pen(new solidbrush(color.red) , 3) ;
                    }
                    if (i != 0)
                    {
                        g.drawline(pen , ix , iy , intwidth * (i * 2 + 1) + 5 , m_intheight /3 * 2 – intheight + 5) ;                    
                    }
                    ix = intwidth * (i * 2 + 1) + 5 ;                                 
                    iy = m_intheight / 3 * 2 – intheight + 5 ;

                    //画饼图下方图例文字
                    //计算矩形大小
                    int intrectsize = m_intheight / 3 / (m_arritems.count * 2) – 1 ;
                    intrectsize = intrectsize > 12 ? 12 : intrectsize ;

                    //画颜色方块
                    g.fillrectangle(new solidbrush(item.color) , intrectsize * 2 ,
                        intrectsize * (i * 2 + 1) + m_intheight / 3 * 2 + 5
                        ,intrectsize , intrectsize) ;  
                    //写文字
                    g.drawstring(intpercent.toint32().tostring() + "%  " + item.text ,
                                new font("宋体" , intrectsize) ,
                                new solidbrush(item.color) , intrectsize * 4 ,
                                intrectsize * ( i * 2 + 1) + m_intheight / 3 * 2 + 5) ;
                }

                //清空
                pen.dispose() ;
            }

            //清控对象
            g.dispose() ;

            //保存为jpg格式
            try
            {
                mybmp.save(a_strfilename , system.drawing.imaging.imageformat.jpeg) ;
            }
            catch(exception e)
            {
                throw(new exception("保存图片失败:" + e.tostring())) ;
            }

            mybmp.dispose() ;

            
            
        }

    }

    /// <summary>
    /// 统计图项目类
    /// </summary>
    /// <remarks>
    ///  构造一个统计图项目，属性有要显示的文字、所占的百分比以及想显示的颜色。
    /// </remarks>
    public class chartitem : object
    {
        /// <summary>
        /// 要显示的文字
        /// </summary>
        private string m_strtext ;

        /// <summary>
        /// 数量
        /// </summary>
        private int m_intcount ;

        /// <summary>
        /// 颜色
        /// </summary>
        private system.drawing.color m_objcolor ;

        //属性
        public string text
        {
            get
            {
                return m_strtext ;
            }
            set
            {
                m_strtext = value ;
            }
        }

        public int count
        {
            get
            {
                return m_intcount ;
            }
            set
            {
                m_intcount = value ;
            }
        }
        public system.drawing.color color
        {
            get
            {
                return m_objcolor ;
            }
            set
            {
                m_objcolor = value ;
            }
        }

        /// <summary>
        /// 构造函数
        /// </summary>
        public chartitem()
        {
            m_strtext = "" ;
            m_intcount = 0 ;
            m_objcolor = color.white ;
        }

        /// <summary>
        /// 重载构造函数
        /// </summary>
        /// <param name="a_strtext"> </param>
        /// <param name="a_intpercent"> </param>
        /// <param name="a_objcolor"> </param>
        public chartitem(string a_strtext , int a_intcount , system.drawing.color a_objcolor)
        {
            m_strtext = a_strtext ;
            m_objcolor = a_objcolor ;
            m_intcount = a_intcount ;
        }
    }
}