.NET中将数据导出（导出）Excel文件_.net6 導出excel

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）
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 += "\t";
                        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 += "\t";
                            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);
                }
            }
}

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()+"\n";//当当前列为最后一列时要换行
                        else
                           columnHeader += dsTable.Columns[i].Caption.ToString()+"\t";     
                }
                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] + "\n";//当当前列为最后一列时换行
                        else
                            columnContent += dr[j] + "\t";
                    }
                    Response.Write(columnContent);
                    columnContent = "";
                }
                Response.End();   
            }
        }

 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;
        }