改进上一篇读取EXCEL的数据到datagridview（增加导出Excel功能）

 

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

namespace WindowsApplication1
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.openFileDialog1.ShowDialog();
            this.textBox1.Text = this.openFileDialog1.FileName;
        }

        private void button2_Click(object sender, EventArgs e)
        {
           string fileName = "";
           fileName = this.textBox1.Text;
           if (this.textBox1.Text != "")
           {
               try
               {
                   string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = " + fileName + " ;Extended Properties=Excel 8.0";
                   System.Data.OleDb.OleDbConnection myConn = new System.Data.OleDb.OleDbConnection(strCon);
                   string strCom = " SELECT * FROM [punishCase$] ";
                   System.Data.OleDb.OleDbDataAdapter myCommand = new System.Data.OleDb.OleDbDataAdapter(strCom, myConn);
                   System.Data.DataTable dt = new System.Data.DataTable();
                   myCommand.Fill(dt);
                   this.dataGridView1.DataSource = dt;
                   this.label1.Text = myConn.State.ToString();
                   MessageBox.Show("导入成功");

               }
               catch
               {
                   MessageBox.Show("请选择案件导入的EXCEL");

               }
             
               
              
           }
           else
           {
               MessageBox.Show("请选择Excel文件");
           }



        }

        private void button3_Click(object sender, EventArgs e)
        {
            SaveFileDialog saveFileDialog = new SaveFileDialog();

            saveFileDialog.Filter = "Execl files (*.xls)|*.xls";

            saveFileDialog.FilterIndex = 0;

            saveFileDialog.RestoreDirectory = true;

            saveFileDialog.CreatePrompt = true;

            saveFileDialog.Title = "Export Excel File To"; 


            saveFileDialog.ShowDialog();


            Stream myStream;

            myStream = saveFileDialog.OpenFile();

            //StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding("gb2312"));

            StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding(-0));

            string str = "";

            try

            {

                //写标题

                for (int i = 0; i < dataGridView1.ColumnCount; i++)

                {

                    if (i > 0)

                    {

                        str += "\t";

                    }

                    str += dataGridView1.Columns[i].HeaderText;

                }


                sw.WriteLine(str);



                //写内容

                for (int j = 0; j < dataGridView1.Rows.Count; j++)

                {

                    string tempStr = "";

                    for (int k = 0; k < dataGridView1.Columns.Count; k++)

                    {

                        if (k > 0)

                        {

                            tempStr += "\t";

                        }

                        tempStr += dataGridView1.Rows[j].Cells[k].Value.ToString();

                    }

                    

                    sw.WriteLine(tempStr);                    

                }

                sw.Close();

                myStream.Close();

            }

            catch

            {

                

            }

            finally

            {

                sw.Close();

                myStream.Close();

            }           

      }


        
    }
}