在C#画饼图一中介绍了小王利用C#画了一个平面饼状图,在小王画出来之后,小王开始想入非非了--要是能画出3D的饼状图该多好,于是小王就开始修改showImage.ashx页面了,果然功夫不负有心人,居然给小王做出来了,先看结果:
Yeh!看起来的确比原来帅多了,其实很简单,就是将原来的饼状图画成为椭圆,并在Y轴方向上向下多画了几个饼图,并将其重合在一起而已(这就是3D啦)!
修改后的showImage.ashx代码:
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<%@ WebHandler Language="C#" Class="showImage" %>
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using System;
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using System.Web;
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using System.Drawing;
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using System.Collections;
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using System.Drawing.Imaging;
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using System.Drawing.Drawing2D;
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using System.Data;
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using System.Data.SqlClient;
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using System.Web.Configuration;
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public class showImage : IHttpHandler
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{
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struct department
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{
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public string name;
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public int number;
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}
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public void ProcessRequest (HttpContext context)
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{
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ArrayList departments = new ArrayList();
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department dp;
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int sum=0;
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SolidBrush sb = new SolidBrush(Color.Aqua);
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Random rd = new Random();
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string connstr = "server=(local);database=test;uid=sa;pwd=sa13";
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SqlConnection conn = new SqlConnection(connstr);
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int startAngle = 0;
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int sweepAngle = 45;
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//connect the database
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try
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{
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conn.Open();
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SqlCommand comm = new SqlCommand("select * from department", conn);
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SqlDataReader dr = comm.ExecuteReader();
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while (dr.Read())
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{
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dp.name = dr["departmentName"].ToString();
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dp.number = Convert.ToInt32(dr["departmentNum"]);
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sum += dp.number;
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departments.Add(dp);
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}
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dr.Close();
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}
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catch (Exception ex)
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{
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throw new Exception(ex.Message);
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}
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finally
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{
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conn.Close();
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}
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//Draw the pie of the every department
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if (departments.Count > 0)
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{
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using (Bitmap bm = new Bitmap(200,260))
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{
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using (Graphics gp = Graphics.FromImage(bm))
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{
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gp.SmoothingMode = SmoothingMode.AntiAlias;
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gp.Clear(Color.White);
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//Rectangle rect = new Rectangle(0, 0, 200, 200);
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int pointX = 0;
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int pointY = 20;
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gp.DrawLine(Pens.Black, 10, 204, 190, 204);
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bool single = true;
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int y = 210;
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for (int i = 0; i < departments.Count; i++)
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{
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dp = (department)departments[i];
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sb.Color = Color.FromArgb(rd.Next(255), rd.Next(255), rd.Next(255));
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sweepAngle = Convert.ToInt32(360 * Convert.ToSingle(dp.number) / Convert.ToSingle(sum));
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//gp.FillPie(sb, rect, startAngle, sweepAngle);
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if (startAngle < 180)
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{
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for (int height = 0; height < 8; height++)
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{
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gp.FillPie(Brushes.Black, pointX, pointY + height, 200, 100, startAngle, sweepAngle);
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}
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}
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gp.FillPie(sb, pointX, pointY, 200, 100, startAngle, sweepAngle);
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startAngle += sweepAngle;
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if (single)
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{
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gp.FillRectangle(sb, new Rectangle(10, y, 20, 15));
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gp.DrawString(dp.name, new Font("Tahoma", 8, FontStyle.Regular), Brushes.Black, new PointF(30, y));
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single = false;
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}
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else
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{
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gp.FillRectangle(sb, new Rectangle(110, y, 20, 15));
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gp.DrawString(dp.name, new Font("Tahoma", 8, FontStyle.Regular), Brushes.Black, new PointF(130, y));
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single = true;
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y += 20;
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}
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}
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//save the image in the page
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gp.DrawLine(Pens.Black, 10, 258, 190, 258);
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context.Response.ContentType = "Image/GIF";
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context.Response.Clear();
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context.Response.BufferOutput = true;
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bm.Save(context.Response.OutputStream, ImageFormat.Gif);
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}
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}
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}
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}
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public bool IsReusable
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{
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get
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{
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return false;
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}
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}
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}

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