数据库文件转化为excel文件

excel文件在日常生活中的作用毋庸置疑，面对小数据量，我们通常采用一一录入的方式，但是面对大量的数据的时候，我们可能就需要采用其他的办法。举个最近的例子：我们毕业设计的时候，论文选题没有使用教学管理系统，而是班委把纸质的题目集拿到班级，然后随机的抽取后汇总电子档交给院系，120多人，大量的数据需要录入，想必没有人愿意这样做~我想采用的做法是用ASP.NET制作一个网页，然后让同学登录网页，随机抽取题目，并将抽取的结果显示在页面上，等所有的同学抽取完毕，班委直接下载生成的excel表格即可。

下面是winform的演示结果

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.IO;

namespace download
{
    public partial class Form1 : Form
    {
        public void con()
        {
            SqlConnection downcon = new SqlConnection();
            downcon.ConnectionString = @"Initial Catalog=stuinfo;Data Source=(local);Integrated Security=SSPI; User Instance = false";
            downcon.Open();
            SqlCommand downcom = new SqlCommand("",downcon);
            downcom.CommandText = @"select * from stucard";
            SqlDataAdapter downda = new SqlDataAdapter(downcom);
            DataSet downset = new DataSet();
            downda.Fill(downset, "stucard");
            dataGridView1.DataSource = downset.Tables["stucard"];
            downcon.Close();
        }

        public Form1()
        {
            InitializeComponent();
            con();

        }

        private void button1_Click(object sender, EventArgs e)
        {
            SaveFileDialog newdlg = new SaveFileDialog();
            newdlg.InitialDirectory = @"C:\Documents and Settings\Administrator\桌面";
            newdlg.Filter = "Execl files (*.xls)|*.xls";
            newdlg.ShowDialog();
            Stream myStream;
            myStream = newdlg.OpenFile();
            StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding(-0));
            string str = "";

            try
            {
                for (int i = 0; i < dataGridView1.ColumnCount; i++)
                {
                    if (i > 0)
                        str += "\t";
                    str += dataGridView1.Columns[i].HeaderText;
                }
                sw.WriteLine(str);
                for (int j = 0; j < dataGridView1.Rows.Count-1; j++)
                {
                    string contentstr = "";
                    for (int k = 0; k < dataGridView1.Columns.Count; k++)
                    {
                        if (k > 0)
                        {
                            contentstr += "\t";
                        }
                        contentstr += dataGridView1.Rows[j].Cells[k].Value.ToString();
                    }
                    sw.WriteLine(contentstr);
                }
                sw.Close();
                myStream.Close();
            }
            catch (Exception g)
            {
                MessageBox.Show(g.Message);
            }
            finally
            {
                sw.Close();
                myStream.Close();
            }
        }

    }
}

上述代码是excel的列名，也是数据库的字段名称的生成。由于二者要对应，而且显示在excel的对应列上，这是\t是关键。