NET中将数据导出（导入）Excel文件

我们在WinForm应用程序或者Web程序中都会遇到需要将DataGridView或者DataSet中的数据导出成为Excel类型的.xls文件。下面就通过一个示例向大家演示在WinForm程序中如何将DataGridView中的数据导出为Excel文件，从DataSet中将数据导出为Excel的方法跟这个差不多的，这里就不再介绍了。

Private void DataGridViewToExcel(DataGridView dgv)
{
            SaveFileDialog sfDialog = new SaveFileDialog();//保存导出的excel对话框
            sfDialog.Filter = 'Excel Files(*.xls)|*.xls';//文件过滤器，只能保存为.xls类型的文件
            sfDialog.CheckFileExists = false;//如果用户指定不存在的文件名是否提示
            sfDialog.CheckPathExists = false;//如果用户指定不存在的路径是否提示
            sfDialog.FilterIndex = 0;
            sfDialog.RestoreDirectory = true;
            sfDialog.CreatePrompt = true;//如果该文件不存在则提示用户创建新文件
            sfDialog.Title = '保存为Excel 文件！';
             if (sfDialog.ShowDialog() == DialogResult.OK)
            {
                Stream saveStream = sfDialog.OpenFile();//打开要保存的excel文件
                StreamWriter sw = new StreamWriter(saveStream, Encoding.GetEncoding(-0));//以特定的编码向流中插入字符，GetEncoding（-0）<BR>首选编码的代码页标识符。- 或 - 0
                string columnTitle = '';
                try
                {
                    for (int i = 0; i < dgv.ColumnCount; i++)
                    {
                        if (i > 0)
                            columnTitle += ' ';
                        columnTitle += dgv.Columns[i].HeaderText;
                    }
                    sw.WriteLine(columnTitle);//写入标题行
                    for (int j = 0; j < dgv.RowCount; j++)
                    {
                        string columnValue='';
                        for(int k=0;k<dgv.ColumnCount;k++)
                        {
                            if(k>0)
                            columnValue += ' ';
                            if (dgv.Rows[j].Cells[k].Value.ToString() == '')
                            {
                                columnValue += '';
                            }
                            else
columnValue += dgv.Rows[j].Cells[k].Value.ToString().Trim();
                        }
                        sw.WriteLine(columnValue);//将信息逐条的写入excel文件
                    }
                    sw.Close();
                    saveStream.Close();
                }
                catch(Exception e)
                {
                    MessageBox.Show(e.Message);
                }
            }
}

下面向大家演示一下如何在Asp.net中如何将数据导出为Excel 文件，这里只是做一个简单的演示，所以并没有太多的布局，页面只有一个按钮，我们在按钮里处理事件如下：

protected void btndstoexcel_Click(object sender, EventArgs e)
        {
            using (SqlConnection sqlConn = new SqlConnection('Initial Catalog=Manager;Integrated Security=true;data source=.'))
            {
                sqlConn.Open();
                SqlCommand sqlCmd = new SqlCommand('select * from associator',sqlConn);
                SqlDataAdapter sdAdapter = new SqlDataAdapter(sqlCmd);
                DataSet ds = new DataSet();
                sdAdapter.Fill(ds, 'Result');//连接数据库，并将信息读进DataSet中
                Response.ContentEncoding = Encoding.GetEncoding('GB2312');//设置编码格式
           Response.ContentType='application/vnd.ms-excel';//设置输入类型为Excel文件，指定返回的是一个不能被客户端读取的流，必须被下载
                Response.AddHeader('Content-Disposition', 'attachment;filename=Test.xls');//添加Http表头，将文件保存为Test.xls
                string columnHeader = '';//保存表头字符
                string columnContent = '';//保存每行的数据内容
                DataTable dsTable = ds.Tables['Result'];
                for (int i = 0; i < dsTable.Columns.Count; i++)
                {
                        if (i == dsTable.Columns.Count - 1)
                            columnHeader += dsTable.Columns[i].Caption.ToString()+' ';//当当前列为最后一列时要换行
                        else
                           columnHeader += dsTable.Columns[i].Caption.ToString()+' ';     
                }
                Response.Write(columnHeader);
  //添加每行的数据信息            
    foreach(DataRow dr in dsTable.Rows)
                {
                    for(int j=0;j<dsTable.Columns.Count;j++)
                    {
                        if (j == dsTable.Columns.Count - 1)
                            columnContent += dr[j] + ' ';//当当前列为最后一列时换行
                        else
                            columnContent += dr[j] + ' ';
                    }
                    Response.Write(columnContent);
                    columnContent = '';
                }
                Response.End();   
            }
        }

说完了数据导出，我们再来谈一下数据的导入，这里演示从Excel文件中读取数据，代码很简单，在这里就不做过多的累述了。希望可以给大家有所启发。

private void ExcelToDataGridView(DataGridView dgv)
       {
           OpenFileDialog dlg = new OpenFileDialog();
           dlg.Filter = 'Execl files (*.xls)|*.xls';
           dlg.CheckFileExists = false;
           dlg.CheckPathExists = false;
           dlg.FilterIndex = 0;
           dlg.RestoreDirectory = true;
           dlg.Title = '将Excel文件数据导入到DataSet';
           dlg.ShowDialog();
 
           DataSet ds = new DataSet();
           string strConn = 'Provider=Microsoft.Jet.OLEDB.4.0;Data Source=' + dlg.FileName.Trim() + ';Extended Properties='Excel 8.0;HDR=False;IMEX=1'';
           using (OleDbConnection OleConn = new OleDbConnection(strConn))
           {
               OleConn.Open();
               String sql = 'SELECT * FROM [Sheet1$]';
               OleDbDataAdapter OleDaExcel = new OleDbDataAdapter(sql, OleConn);
               OleDaExcel.Fill(ds);
               OleConn.Close();
           }
               dgv.DataSource = ds.Tables[0].DefaultView;
       }