ASP.NET画图系列之实现Pie图(圆饼图)

ASP.NET自身提供的画图功能也是很强大的，在实际的项目中有时也会经常用到的，实现这样的功能方法很多，诸如水晶报表之类也可以实现，但有时我们只想实现单一的某些功能或许就可以考虑画图的功能了。实现画图其实并不难，这里介绍的是通过Graphics类来产生一个Bitmap对象，接下去你是直接写到页面还是生成某个图片保存至某个路径，看你自己方便了,gfreesky在这里选择了后者作为示例，如果各位朋友有什么不明白的可以留言或Email给我，我的Email:gfreesky@gmail.com

废话不多说，先看下效果：

好了，切入正题，首先页面部分

 

<form id="form1" runat="server">
        <div>
            <asp:Image ID="Image1" runat="server" />
        </div>
    </form>

后台cs：

using System.Data.SqlClient;
using System.Drawing;
using System.Drawing.Imaging;
using SkyNet.Chart;
using SkyNet.OA.OAWebUtility;

public partial class SkyNetChart_MyBar : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

        if (!IsPostBack)
        {
            InitChart();
        }
    }
    private void InitChart()
    {

        Bar barImg = new Bar(); //定义一个画图类实例
        barImg.Title = "2008年销售情况统计表";
        barImg.TextColor = Color.Red;
        barImg.DS = GetDSBySale(); //这里若不设置，则采用默认的

        string imgPath = "../ChartImages/" + "MyBar.jpg";
        ChartHelper.CreateChartByBar(barImg, imgPath, ImageFormat.Jpeg);
        this.Image1.ImageUrl = imgPath;
    }
    private DataSet GetDSBySale()
    {
        string constr = "server=.;database=test;uid=sa;pwd=";
        SqlConnection con = new SqlConnection(constr);
        con.Open();
        string cmdStr = "select CountryName,SaleSum from SaleOfCountry ";   //注意前面第一个字段对应Keys,第二个字段为Values
        SqlDataAdapter da = new SqlDataAdapter(cmdStr, con);
        DataSet ds = new DataSet();
        da.Fill(ds, "SaleOfCountry");
        return ds;
    }

}

 

我这里为了方便就把某些代码写到页面里了，读者请自行考虑！

SkyNet.Chart是一个命名空间，里面有Pie类，随后我将贴出，还包括我后面要讲的Curve类、Bar类等

其中的ChartHelper.CreateChartByPie(pieImg, imgPath, ImageFormat.Jpeg)方法我是在另外一个命名空间里定义的，命名空间是SkyNet.OA.OAWebUtility,随后我也会贴出

下面贴出SkyNet.Chart空间下的Pie类

using System.Drawing;
using System.Data;

namespace SkyNet.Chart
{
    public class Pie
    {

        #region 私有字段
        private Graphics objGraphics; //Graphics 类提供将对象绘制到显示设备的方法
        private Bitmap objBitmap; //位图对象

        private int m_Width = 700; //图像宽度
        private int m_Height = 400; //图像高度
        private string m_Title = "××公司销售情况统计表";
        private string m_Unit = "万元";
        //键
        private string[] m_Keys = new string[] { "一月", "二月", "三月", "四月", "五月", "六月", "七月", "八月", "九月", "十月", "十一月", "十二月" };
        //值
        private float[] m_Values = new float[] { 21.5f, 36.2f, 48.7f, 55.4f, 21.6f, 12.8f, 99.5f, 36.4f, 78.2f, 56.4f, 45.8f, 66.4f };
        private Color m_BgColor = Color.Snow; //背景
        private Color m_TextColor = Color.Black; //文字颜色
        private Color m_BorderColor = Color.Black; //整体边框颜色
        //Pie颜色数组
        private Color[] m_PieColor = new Color[]{Color.Green,Color.Red,Color.Yellow,Color.Blue,Color.Orange,Color.Aqua,
                Color.SkyBlue,Color.DeepPink,Color.Teal,Color.Brown,Color.Navy,Color.Pink};

        private DataSet m_ds;
        private Brush m_titleBrush = Brushes.Black; //标题的画笔颜色
        #endregion

        #region 属性设置

        public DataSet DS
        {
            get { return m_ds; }
            set { m_ds = value; }
        }
        /// <summary>
        /// 标题的画笔颜色
        /// </summary>
        public Brush TitleBrush
        {
            get { return m_titleBrush; }
            set { m_titleBrush = value; }
        }

        public string[] Keys
        {
            set
            {
                m_Keys = value;
            }
            get
            {
                return m_Keys;
            }
        }

        public float[] Values
        {
            set
            {
                m_Values = value;
            }
            get
            {
                return m_Values;
            }
        }
        public int Width
        {
            set
            {
                if (value < 300)
                {
                    m_Width = 300;
                }
                else
                {
                    m_Width = value;
                }
            }
            get
            {
                return m_Width;
            }
        }

        public int Height
        {
            set
            {
                if (value < 300)
                {
                    m_Height = 300;
                }
                else
                {
                    m_Height = value;
                }
            }
            get
            {
                return m_Height;
            }
        }

        public string Title
        {
            set
            {
                m_Title = value;
            }
            get
            {
                return m_Title;
            }
        }

        public string Unit
        {
            set
            {
                m_Unit = value;
            }
            get
            {
                return m_Unit;
            }
        }


        public Color BgColor
        {
            set
            {
                m_BgColor = value;
            }
            get
            {
                return m_BgColor;
            }
        }

        public Color TextColor
        {
            set
            {
                m_TextColor = value;
            }
            get
            {
                return m_TextColor;
            }
        }

        public Color BorderColor
        {
            set
            {
                m_BorderColor = value;
            }
            get
            {
                return m_BorderColor;
            }
        }

        public Color[] PieColor
        {
            set
            {
                m_PieColor = value;
            }
            get
            {
                return m_PieColor;
            }
        }
        #endregion

        #region 分配颜色
        private Color GetColor(int i) //分配各Pie的颜色
        {
            try
            {
                if (0 < i && i < PieColor.Length)
                {
                    return PieColor[i];
                }
                else if (i >= PieColor.Length)
                {
                    int j = i % PieColor.Length;
                    return PieColor[j];
                }
                else
                {
                    return Color.Green;
                }
            }
            catch
            {
                return Color.Green;
            }
        }
        #endregion

        //生成图像并返回bmp图像对象
        public Bitmap CreateImage()
        {
            InitializeGraph();

            DrawRight(ref objGraphics);

            DrawContent(ref objGraphics);

            return objBitmap;
        }


        //初始化Keys和Values值和填充图像区域，画出边框，初始标题
        private void InitializeGraph()
        {
            //根据DS给Keys和Values赋值
            SetKeyValues();

            //根据给定的高度和宽度创建一个位图图像
            objBitmap = new Bitmap(Width, Height);

            //从指定的 objBitmap 对象创建 objGraphics 对象 (即在objBitmap对象中画图)
            objGraphics = Graphics.FromImage(objBitmap);

            //根据给定颜色(LightGray)填充图像的矩形区域 (背景)
            objGraphics.DrawRectangle(new Pen(BorderColor, 1), 0, 0, Width, Height);
            objGraphics.FillRectangle(new SolidBrush(BgColor), 1, 1, Width - 2, Height - 2);

            //初始化标题
            CreateTitle(ref objGraphics);
        }

        //根据DS给Keys和Values赋值
        private void SetKeyValues()
        {
            if (DS != null)
            {
                DataTable dt = DS.Tables[0];
                DataRow dr;
                int rows = dt.Rows.Count;
                string[] keys = new string[rows];
                float[] values = new float[rows];
                for (int i = 0; i < rows; i++)
                {
                    dr = dt.Rows[i];
                    keys[i] = dr[0].ToString();
                    values[i] = Convert.ToSingle(dr[1]) / 10000;
                }
                Keys = keys;
                Values = values;
            }
            else
            {
                Keys = m_Keys;
                Values = m_Values;
            }
        }


        //初始化右边说明部分
        private void DrawRight(ref Graphics objGraphics)
        {
            objGraphics.DrawString(String.Format("单位：{0}", Unit), new Font("宋体", 10), new SolidBrush(TextColor), Width - 95, 30);

            Point KeysPoint = new Point(Width - 120, 50);
            Point KeysTextPoint = new Point(Width - 90, 50);
            for (int i = 0; i < Keys.Length; i++)
            {
                objGraphics.DrawRectangle(new Pen(BorderColor, 1), KeysPoint.X, KeysPoint.Y, 21, 11);
                objGraphics.FillRectangle(new SolidBrush(GetColor(i)), KeysPoint.X, KeysPoint.Y, 20, 10);
                objGraphics.DrawString(String.Format("{0} {1}", Keys[i], Values[i]), new Font("宋体", 10), new SolidBrush(TextColor), KeysTextPoint);
                KeysPoint.Y += 15;
                KeysTextPoint.Y += 15;
            }
            //画右边的矩形边框(自己画的)
            //objGraphics.DrawRectangle(Pens.Black, Width - 130, 0, 130, Height*4/5);
            //objGraphics.DrawString("示图", new Font("宋体",12,FontStyle.Bold), Brushes.Red, Width - 130 / 2 - 25, Height * 4 / 5 - 25);
        }

        private void DrawContent(ref Graphics objGraphics)
        {
            float Sum = 0;
            float StartAngle = 0;
            float SweepAngle = 0;
            float CircleHeight = 0;
            float CircleX = 0;
            float CircleY = 0;

            for (int i = 0; i < Values.Length; i++)
            {
                Sum += Values[i];
            }
            if (Width > Height)
            {
                CircleHeight = Height - 100;
            }
            else
            {
                CircleHeight = Width - 150;
            }
            CircleX = (Width - 150) / 2 - CircleHeight / 2;
            CircleY = Height - 50 - CircleHeight;
            for (int i = 0; i < Values.Length; i++)
            {
                SweepAngle = (Values[i] / Sum) * 360;
                objGraphics.DrawPie(new Pen(BorderColor, 1), CircleX, CircleY, CircleHeight, CircleHeight, StartAngle, SweepAngle);
                objGraphics.FillPie(new SolidBrush(GetColor(i)), CircleX, CircleY, CircleHeight, CircleHeight, StartAngle, SweepAngle);
                StartAngle += SweepAngle;
            }
        }
        //初始化标题
        private void CreateTitle(ref Graphics objGraphics)
        {
            objGraphics.DrawString(Title, new Font("宋体", 16, FontStyle.Bold), TitleBrush, new Point(5, 5));
        }
    }
}

 

至此，Pie结束

下面贴出ChartHelper类

 

 public class ChartHelper
    {
        /// <summary>
        /// 创建一个Pie图--圆饼图
        /// </summary>
        /// <param name="pieImg">Pie类的实例(设置标题、宽度、高度等)</param>
        /// <param name="imgPath">生成Pie图的图片路径(相对路径)</param>
        /// <param name="imgFormat">生成Pie图的图片格式(如：ImageFormat.Jpeg)</param>
        public static void CreateChartByPie(Pie pieImg,string imgPath,ImageFormat imgFormat)
        {
            try
            {
                if (pieImg == null)
                {
                    pieImg.Title = "Pie图统计表示例";
                    pieImg.TitleBrush = Brushes.Red;
                    pieImg.Width = 800;
                    pieImg.Height = 500;
                }
                Bitmap bmp = pieImg.CreateImage();
                string savePath = HttpContext.Current.Server.MapPath(imgPath);
                bmp.Save(savePath, imgFormat);
            }
            catch(Exception ee)
            {
                throw ee;
            }
        }
}

 

好到此，画图全部结束，如果以上您有看不懂的，请留言或发Email