c#使用NPOI快速導出到Excel

接上篇博文《C#快速導出到excel》：因爲此種方法不能導出成.xlsx格式，爲解決此問題，本次分享使用NPOI。

參考：https://www.cnblogs.com/lazyneal/p/6148912.html

一、添加程序包。

在項目名右鍵。

選擇管理NuGet程序包，瀏覽處搜索NPOI並安裝。

二、代碼引用。

using System.IO;
using System.Data.SqlClient;
using System.Diagnostics;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;

三、導出Excel方法：

public void ExportDataToExcel(DataTable TableName, string FileName)
        {
            SaveFileDialog saveFileDialog = new SaveFileDialog();
            //設置文件標題
            saveFileDialog.Title = "導出Excel文件";
            //設置文件類型
            saveFileDialog.Filter = "Excel 工做簿(*.xlsx)|*.xlsx|Excel 97-2003 工做簿(*.xls)|*.xls";
            //設置默認文件類型顯示順序  
            saveFileDialog.FilterIndex = 1;
            //是否自動在文件名中添加擴展名
            saveFileDialog.AddExtension = true;
            //是否記憶上次打開的目錄
            saveFileDialog.RestoreDirectory = true;
            //設置默認文件名
            saveFileDialog.FileName = FileName;
            //按下肯定選擇的按鈕  
            if (saveFileDialog.ShowDialog() == DialogResult.OK)
            {
                //得到文件路徑 
                string localFilePath = saveFileDialog.FileName.ToString();

                //數據初始化
                int TotalCount;     //總行數
                int RowRead = 0;    //已讀行數
                int Percent = 0;    //百分比

                TotalCount = TableName.Rows.Count;
                lblStatus.Text = "共有" + TotalCount + "條數據";
                lblStatus.Visible = true;
                barStatus.Visible = true;

                //NPOI
                IWorkbook workbook;
                string FileExt = Path.GetExtension(localFilePath).ToLower();
                if (FileExt == ".xlsx")
                {
                    workbook = new XSSFWorkbook();
                }
                else if (FileExt == ".xls")
                {
                    workbook = new HSSFWorkbook();
                }
                else
                {
                    workbook = null;
                }
                if (workbook == null)
                {
                    return;
                }
                ISheet sheet = string.IsNullOrEmpty(FileName) ? workbook.CreateSheet("Sheet1") : workbook.CreateSheet(FileName);


                //秒鐘
                Stopwatch timer = new Stopwatch();
                timer.Start();

                try
                {
                    //讀取標題  
                    IRow rowHeader = sheet.CreateRow(0);
                    for (int i = 0; i < TableName.Columns.Count; i++)
                    {
                        ICell cell = rowHeader.CreateCell(i);
                        cell.SetCellValue(TableName.Columns[i].ColumnName);
                    }

                    //讀取數據  
                    for (int i = 0; i < TableName.Rows.Count; i++)
                    {
                        IRow rowData = sheet.CreateRow(i + 1);
                        for (int j = 0; j < TableName.Columns.Count; j++)
                        {
                            ICell cell = rowData.CreateCell(j);
                            cell.SetCellValue(TableName.Rows[i][j].ToString());
                        }
                        //狀態欄顯示
                        RowRead++;
                        Percent = (int)(100 * RowRead / TotalCount);
                        barStatus.Maximum = TotalCount;
                        barStatus.Value = RowRead;
                        lblStatus.Text = "共有" + TotalCount + "條數據，已讀取" + Percent.ToString() + "%的數據。";
                        Application.DoEvents();
                    }

                    //狀態欄更改
                    lblStatus.Text = "正在生成Excel...";
                    Application.DoEvents();

                    //轉爲字節數組  
                    MemoryStream stream = new MemoryStream();
                    workbook.Write(stream);
                    var buf = stream.ToArray();

                    //保存爲Excel文件  
                    using (FileStream fs = new FileStream(localFilePath, FileMode.Create, FileAccess.Write))
                    {
                        fs.Write(buf, 0, buf.Length);
                        fs.Flush();
                        fs.Close();
                    }

                    //狀態欄更改
                    lblStatus.Text = "生成Excel成功，共耗時" + timer.ElapsedMilliseconds + "毫秒。";
                    Application.DoEvents();
                    
                    //關閉秒鐘
                    timer.Reset();
                    timer.Stop();

                    //成功提示
                    if (MessageBox.Show("導出成功，是否當即打開？", "提示", MessageBoxButtons.YesNo, MessageBoxIcon.Information) == DialogResult.Yes)
                    {
                        System.Diagnostics.Process.Start(localFilePath);
                    }

                    //賦初始值
                    lblStatus.Visible = false;
                    barStatus.Visible = false;
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
                finally
                {
                    //關閉秒鐘
                    timer.Reset();
                    timer.Stop();
                    //賦初始值
                    lblStatus.Visible = false;
                    barStatus.Visible = false;
                }
            }
        }

四、結果演示：