把.dat文件中的数据画柱状图显示
using System;using System.Collections.Generic;
using
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Imaging;
using System.Data.SqlClient;
namespace DrawColumn
{
public partial class Frm_Main : Form
{
public Frm_Main()
{
InitializeComponent();
}
SqlConnection con;
SqlCommand cmd;
private void button1_Click(object sender, EventArgs e)
{
}
private void Conn()
{
con = new SqlConnection("server=WRET-MOSY688YVW\\MRGLL;uid=sa;pwd=;database=db_TomeOne");
con.Open();
}
private void ShowPic()
{
Conn(); //打开数据库连接
using (cmd = new SqlCommand("SELECT TOP 3 * FROM tb_Rectangle order by t_Num desc", con))
{
SqlDataReader dr = cmd.ExecuteReader(); //创建SqlDataReader对象
Bitmap bitM = new Bitmap(this.panel1.Width, this.panel1.Height); //创建画布
Graphics g = Graphics.FromImage(bitM); //创建Graphics对象
g.Clear(Color.White); //设置画布背景
for (int j = 0; j < 4; j++) //开始读取数据库中的数据并绘图
{
if (dr.Read()) //读取记录集
{
int x, y, w, h; //声明变量存储坐标和大小
g.DrawString(dr[0].ToString(), new Font("宋体", 8, FontStyle.Regular), new SolidBrush(Color.Black), 76 + 40 * j, this.panel1.Height - 16); //绘制文字
x = 78 + 40 * j; //x坐标
y = this.panel1.Height - 20 - Convert.ToInt32((Convert.ToDouble(Convert.ToDouble(dr[1].ToString()) * 20 / 100))); //y坐标
w = 24; //宽
h = Convert.ToInt32(Convert.ToDouble(dr[1].ToString()) * 20 / 100);//高
g.FillRectangle(new SolidBrush(Color.FromArgb(56, 129, 78)), x, y, w, h);//开始绘制柱形图
}
}
this.panel1.BackgroundImage = bitM; //显示绘制的柱形图
}
}
private void button1_Click_1(object sender, EventArgs e)
{
ShowPic();
}
}
}
上面这个例子给出的是把数据库的数据画成柱状图显示，我是新手，还不了解数据库，请问能把.DAT文件中的数据画成柱状图吗？怎么做？谢谢！
