数据库编程

开发平台：
Visual C++

showImage .cs：源码内容
							﻿using System;
using System.Web;
using System.Web.UI;
using System.Drawing;
using System.Collections;
using System.Drawing.Imaging;
using System.Drawing.Drawing2D;
using System.Data;
using System.Data.SqlClient;
using System.Web.Configuration;
public class showImage 
{
    struct department
    {
        public string name;
        public int number;
    }
    
    public void ProcessRequest ()
    {
        ArrayList departments = new ArrayList();
        department dp;
       
        SolidBrush sb = new SolidBrush(Color.Aqua);
        Random rd = new Random();
        SqlConnection connection = DB.connect_la();
        int sum = 0;
        int success = 0;
        int startAngle = 0;
        int sweepAngle = 45;
        //connect the database
        try
        {
            connection.Open();
           
             SqlCommand comm1 = new SqlCommand("select count(sut_id) from stu_tea where state = '已选择'", connection);
             SqlDataReader dr1 = comm1.ExecuteReader();
             if (dr1.Read())
             {
                 dp.name = "已确定导师";
                 dp.number = Convert.ToInt32(dr1.GetInt32(0));
                 success = dr1.GetInt32(0);
                 departments.Add(dp);
             }
             dr1.Close();
             SqlCommand comm2 = new SqlCommand("select count(stu_id) from stu_id_num", connection);
             SqlDataReader dr2 = comm2.ExecuteReader();
             if (dr2.Read())
             {
                 dp.name = "未确定导师";
                 sum = dr2.GetInt32(0);
                 dp.number = sum-success;
                 departments.Add(dp);
             }
             dr2.Close();
         }
         catch (Exception ex)
         {
             throw new Exception(ex.Message);
         }
         finally
         {
             connection.Close();
         }
         //Draw the pie of the every department
         if (departments.Count > 0)
         {
             using (Bitmap bm = new Bitmap(200,260))
             {
                 using (Graphics gp = Graphics.FromImage(bm))
                 {
                     gp.SmoothingMode = SmoothingMode.AntiAlias;
                     gp.Clear(Color.White);
                     //Rectangle rect = new Rectangle(0, 0, 200, 200);
                     int pointX = 0;
                     int pointY = 20;
                     gp.DrawLine(Pens.Black, 10, 204, 190, 204);
                     bool single = true;
                     int y = 210;
                     for (int i = 0; i < departments.Count; i++)
                     {
                        dp = (department)departments[i];
                         sb.Color = Color.FromArgb(rd.Next(255), rd.Next(255), rd.Next(255));
                         sweepAngle = Convert.ToInt32(360 * Convert.ToSingle(dp.number) / Convert.ToSingle(sum));
                         //gp.FillPie(sb, rect, startAngle, sweepAngle);
                        if (startAngle < 180)
                        {
                            for (int height = 0; height < 8; height++)
                            {
                                gp.FillPie(Brushes.Black, pointX, pointY + height, 200, 100, startAngle, sweepAngle);
                            }
                        }
                        gp.FillPie(sb, pointX, pointY, 200, 100, startAngle, sweepAngle);
                        startAngle += sweepAngle;
                        if (single)
                        {
                            gp.FillRectangle(sb, new Rectangle(10, y, 20, 15));
                            gp.DrawString(dp.name, new Font("Tahoma", 8, FontStyle.Regular), Brushes.Black, new PointF(30, y));
                            single = false;
                        }
                        else
                        {
                            gp.FillRectangle(sb, new Rectangle(110, y, 20, 15));
                            gp.DrawString(dp.name, new Font("Tahoma", 8, FontStyle.Regular), Brushes.Black, new PointF(130, y));
                            single = true;
                            y += 20;
                        }
                   }
                    //save the image in the page
                    gp.DrawLine(Pens.Black, 10, 258, 190, 258);
                    string path = System.AppDomain.CurrentDomain.BaseDirectory+"\image\graph1.gif";
                    bm.Save(path);
                }
            }
        }
    }
 
   
   
}

						