Question

在vb中，怎么实现读取SQL2005中的数据，把它绘出曲线图呢？

数据库中有数据，一组时间和其它几组数据，我想以时间为横轴，另一组数据为纵轴，怎么在VB中绘出曲线图呢？求详解！
QQ：328278575

Answer 1

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Drawing.Drawing2D;

using System.Drawing.Imaging;

using System.Drawing;

using System.IO;

/**//// <summary>

/// DrawClass 的摘要说明

/// </summary>

public class DrawClass

...{

public DrawClass()

...{

//

// TODO: 在此处添加构造函数逻辑

//

}

public MemoryStream draw(DataSet ds, int Tnum)

...{

//取得记录数量

int count = ds.Tables[0].Rows.Count;

//记算图表宽度

int wd = 80 + 20 * (count - 1);

//设置最小宽度为800

if (wd < 800) wd = 800;

//生成Bitmap对像

Bitmap img = new Bitmap(wd, 400);

//生成绘图对像

Graphics g = Graphics.FromImage(img);

//定义黑色画笔

Pen Bp = new Pen(Color.Black);

//定义红色画笔

Pen Rp = new Pen(Color.Red);

//定义银灰色画笔

Pen Sp = new Pen(Color.Silver);

//定义大标题字体

Font Bfont = new Font("Arial", 12, FontStyle.Bold);

//定义一般字体

Font font = new Font("Arial", 6);

//定义大点的字体

Font Tfont = new Font("Arial", 9);

//绘制底色

g.DrawRectangle(new Pen(Color.White, 400), 0, 0, img.Width, img.Height);

//定义黑色过渡型笔刷

LinearGradientBrush brush = new LinearGradientBrush(new Rectangle(0, 0, img.Width, img.Height), Color.Black, Color.Black, 1.2F, true);

//定义蓝色过渡型笔刷

LinearGradientBrush Bluebrush = new LinearGradientBrush(new Rectangle(0, 0, img.Width, img.Height), Color.Blue, Color.Blue, 1.2F, true);

//绘制大标题

g.DrawString(ds.Tables[0].Rows[0]["sendid"].ToString() + "号订单发送情况曲线图", Bfont, brush, 40, 5);

//取得当前发送量

int nums = 0;

for (int i = 0; i < count; i++)

...{

nums += Convert.ToInt32(ds.Tables[0].Rows[i]["sendmum"]);

}

//绘制信息简报

string info = "订单发送时间：" + ds.Tables[0].Rows[0]["sendtime"].ToString() + " 曲线图生成时间：" + DateTime.Now.ToString() + " 订单总量：" + Tnum.ToString() + " 当前发送总量：" + nums.ToString();

g.DrawString(info, Tfont, Bluebrush, 40, 25);

//绘制图片边框

g.DrawRectangle(Bp, 0, 0, img.Width - 1, img.Height - 1);

//绘制竖坐标线

for (int i = 0; i < count; i++)

...{

g.DrawLine(Sp, 40 + 20 * i, 60, 40 + 20 * i, 360);

}

//绘制时间轴坐标标签

for (int i = 0; i < count; i += 2)

...{

string st = Convert.ToDateTime(ds.Tables[0].Rows[i]["sendtime"]).ToString("hh:mm");

g.DrawString(st, font, brush, 30 + 20 * i, 370);

}

//绘制横坐标线

for (int i = 0; i < 10; i++)

...{

g.DrawLine(Sp, 40, 60 + 30 * i, 40 + 20 * (count - 1), 60 + 30 * i);

int s = 2500 - 50 * i * 5;

//绘制发送量轴坐标标签

g.DrawString(s.ToString(), font, brush, 10, 60 + 30 * i);

}

//绘制竖坐标轴

g.DrawLine(Bp, 40, 55, 40, 360);

//绘制横坐标轴

g.DrawLine(Bp, 40, 360, 45 + 20 * (count - 1), 360);

//定义曲线转折点

Point[] p = new Point[count];

for (int i = 0; i < count; i++)

...{

p[i].X = 40 + 20 * i;

p[i].Y = 360 - Convert.ToInt32(ds.Tables[0].Rows[i]["sendmum"]) / 5 * 3 / 5;

}

//绘制发送曲线

g.DrawLines(Rp, p);

for (int i = 0; i < count; i++)

...{

//绘制发送记录点的发送量

g.DrawString(ds.Tables[0].Rows[i]["sendmum"].ToString(), font, Bluebrush, p[i].X, p[i].Y - 10);

//绘制发送记录点

g.DrawRectangle(Rp, p[i].X - 1, p[i].Y - 1, 2, 2);

}

//绘制竖坐标标题

g.DrawString("发送量", Tfont, brush, 5, 40);

//绘制横坐标标题

g.DrawString("发送时间", Tfont, brush, 40, 385);

//保存绘制的图片

MemoryStream stream = new MemoryStream();

img.Save(stream, ImageFormat.Jpeg);

return stream;

}

}

然后在页面文件中调用输出

DrawClass dc = new DrawClass();

OracleConnection conn = new OracleConnection(con);

string sql = "select * from atest";

OracleDataAdapter da = new OracleDataAdapter(sql, conn);

DataSet ds = new DataSet();

da.Fill(ds, "atest");

MemoryStream ss=dc.draw(ds, 6);

Response.ContentType = "image/jpeg";

Response.BinaryWrite(ss.ToArray());

图片输出到page页面中也有另外一种方式

FileStream fs = new FileStream(@"c:Curve.jpg", FileMode.Open, FileAccess.Read);

byte[] mydata = new byte[fs.Length];

int Length = Convert.ToInt32(fs.Length);

fs.Read(mydata, 0, Length);

fs.Close();

this.Response.OutputStream.Write(mydata, 0, Length);

this.Response.End();

Answer 2

添加新项里不是有报表吗？要例子吗？
到51aspx.com里输入报表源码的！！自己下载来看看就明白 了