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();
            }
        }

    }
}