C# 將DataGridView中顯示的數據導出到Excel(.xls和.xlsx格式)—NPOI

前言

https://blog.csdn.net/IT_xiao_guang_guang/article/details/104217491

 本地數據庫表中有46785條數據，測試正常
 初次運行程序第一次導出，用時在4-5s左右；此后再導出用時在2-3s左右；可能與緩存有關
 支持導出為.xls和.xlsx格式
 可以自定義字體和字號

 exe測試文件下載地址：https://www.lanzous.com/i95st5g
  密碼：test

實現步驟

一、安裝NPOI

右鍵項目 → "管理NuGet程序包" → 搜索NPOI → 安裝

---

二、創建類

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using NPOI.SS.UserModel;
using NPOI.HSSF.UserModel;//導出xls格式用HSSF
using NPOI.XSSF.UserModel;//導出xlsx格式用XSSF
using System.IO;
using System.Runtime.InteropServices;
using System.Diagnostics;
using NPOI.SS.Util;


namespace ExportToExcel
{
    public class ExportDgvToExcel
    {
        #region  NPOI DataGridView 導出 EXCEL
        /// <summary>
        ///  NPOI DataGridView 導出 EXCEL
        ///  03版Excel-xls最大行數是65536行,最大列數是256列
        ///  07版Excel-xlsx最大行數是1048576行,最大列數是16384列
        /// </summary>
        /// <param name="fileName">默認保存文件名</param>
        /// <param name="dgv">DataGridView</param>
        /// <param name="fontname">字體名稱</param>
        /// <param name="fontsize">字體大小</param> 

        public void ExportExcel(string fileName, DataGridView dgv, string fontname, short fontsize)
        {
            IWorkbook workbook;
            ISheet sheet;
            Stopwatch sw = null;            

            //判斷datagridview中內容是否為空
            if (dgv.Rows.Count == 0)
            {
                MessageBox.Show("DataGridView中內容為空,請先導入數據!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            //保存文件
            string saveFileName = "";
            SaveFileDialog saveFileDialog = new SaveFileDialog();
            saveFileDialog.DefaultExt = "xls";
            saveFileDialog.Filter = "Excel文件(*.xls)|*.xls|Excel文件(*.xlsx)|*.xlsx";
            saveFileDialog.RestoreDirectory = true;
            saveFileDialog.Title = "Excel文件保存路徑";
            saveFileDialog.FileName = fileName;
            MemoryStream ms = new MemoryStream(); //MemoryStream
            if (saveFileDialog.ShowDialog() == DialogResult.OK)
            {            
                //**程序開始計時**//
                sw = new Stopwatch();
                sw.Start();

                saveFileName = saveFileDialog.FileName;

                //檢測文件是否被占用
                if (!CheckFiles(saveFileName))
                {
                    MessageBox.Show("文件被占用,請關閉文件" + saveFileName);
                    workbook = null;
                    ms.Close();
                    ms.Dispose();
                    return;
                }               
            }
            else
            {
                workbook = null;
                ms.Close();
                ms.Dispose();
            }            

            //*** 根據擴展名xls和xlsx來創建對象
            string fileExt = Path.GetExtension(saveFileName).ToLower();
            if (fileExt == ".xlsx")
            {
                workbook = new XSSFWorkbook();           
            }
            else if (fileExt == ".xls")
            {
                workbook = new HSSFWorkbook();        
            }
            else
            {
                workbook = null;
            }
            //***

            //創建Sheet
            if (workbook != null)
            {
                sheet = workbook.CreateSheet("Sheet1");//Sheet的名稱  
            }
            else
            {
                return;
            }                                                  

            //設置單元格樣式
            ICellStyle cellStyle = workbook.CreateCellStyle();
            //水平居中對齊和垂直居中對齊
            cellStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;
            cellStyle.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Center;
            //設置字體
            IFont font = workbook.CreateFont();
            font.FontName = fontname;//字體名稱
            font.FontHeightInPoints = fontsize;//字號
            font.Color = NPOI.HSSF.Util.HSSFColor.Black.Index;//字體顏色
            cellStyle.SetFont(font);

            //添加列名
            IRow headRow = sheet.CreateRow(0);
            for (int i = 0; i < dgv.Columns.Count; i++)
            {
                //隱藏行列不導出
                if (dgv.Columns[i].Visible == true)
                {
                    headRow.CreateCell(i).SetCellValue(dgv.Columns[i].HeaderText);
                    headRow.GetCell(i).CellStyle = cellStyle;
                }                
            }           

            //根據類型寫入內容
            for (int rowNum = 0; rowNum < dgv.Rows.Count; rowNum++)
            {
                ///跳過第一行,第一行為列名
                IRow dataRow = sheet.CreateRow(rowNum + 1);
                for (int columnNum = 0; columnNum < dgv.Columns.Count; columnNum++)
                {
                    int columnWidth = sheet.GetColumnWidth(columnNum) / 256; //列寬

                    //隱藏行列不導出
                    if (dgv.Rows[rowNum].Visible == true && dgv.Columns[columnNum].Visible == true)
                    {
                        //防止行列超出Excel限制
                        if (fileExt == ".xls")
                        {
                            //03版Excel最大行數是65536行,最大列數是256列
                            if (rowNum > 65536)
                            {
                                MessageBox.Show("行數超過Excel限制!");
                                return;
                            }
                            if (columnNum > 256)
                            {
                                MessageBox.Show("列數超過Excel限制!");
                                return;
                            }
                        }
                        else if (fileExt == ".xlsx")
                        {
                            //07版Excel最大行數是1048576行,最大列數是16384列
                            if (rowNum > 1048576)
                            {
                                MessageBox.Show("行數超過Excel限制!");
                                return;
                            }
                            if (columnNum > 16384)
                            {
                                MessageBox.Show("列數超過Excel限制!");
                                return;
                            }
                        }

                        ICell cell = dataRow.CreateCell(columnNum);
                        if (dgv.Rows[rowNum].Cells[columnNum].Value == null)
                        {
                            cell.SetCellType(CellType.Blank);
                        }
                        else
                        {
                            if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.Int32"))
                            {
                                cell.SetCellValue(Convert.ToInt32(dgv.Rows[rowNum].Cells[columnNum].Value));
                            }
                            else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.String"))
                            {
                                cell.SetCellValue(dgv.Rows[rowNum].Cells[columnNum].Value.ToString());
                            }
                            else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.Single"))
                            {
                                cell.SetCellValue(Convert.ToSingle(dgv.Rows[rowNum].Cells[columnNum].Value));
                            }
                            else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.Double"))
                            {
                                cell.SetCellValue(Convert.ToDouble(dgv.Rows[rowNum].Cells[columnNum].Value));
                            }
                            else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.Decimal"))
                            {
                                cell.SetCellValue(Convert.ToDouble(dgv.Rows[rowNum].Cells[columnNum].Value));
                            }
                            else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.DateTime"))
                            {
                                cell.SetCellValue(Convert.ToDateTime(dgv.Rows[rowNum].Cells[columnNum].Value).ToString("yyyy-MM-dd"));
                            }
                            else if (dgv.Rows[rowNum].Cells[columnNum].ValueType.FullName.Contains("System.DBNull"))
                            {
                                cell.SetCellValue("");
                            }    
                        }

                        //設置列寬
                        IRow currentRow;
                        if (sheet.GetRow(rowNum) == null)
                        {
                            currentRow = sheet.CreateRow(rowNum);
                        }
                        else
                        {
                            currentRow = sheet.GetRow(rowNum);
                        }

                        if (currentRow.GetCell(columnNum) != null)
                        {
                            ICell currentCell = currentRow.GetCell(columnNum);
                            int length = Encoding.Default.GetBytes(currentCell.ToString()).Length;

                            if (columnWidth < length)
                            {
                                columnWidth = length + 10; //設置列寬數值
                            }
                        }
                        sheet.SetColumnWidth(columnNum, columnWidth * 256);

                        //單元格樣式
                        dataRow.GetCell(columnNum).CellStyle = cellStyle;
                    }                    
                }
            }

            //保存為Excel文件                  
            workbook.Write(ms);
            FileStream file = new FileStream(saveFileName, FileMode.Create);
            workbook.Write(file);
            file.Close();
            workbook = null;
            ms.Close();
            ms.Dispose();

            //**程序結束計時**//
            sw.Stop();
            double totalTime = sw.ElapsedMilliseconds / 1000.0;

            MessageBox.Show(fileName + " 導出成功\n耗時" + totalTime + "s", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
        #endregion


        #region 檢測文件是否被占用 
        /// <summary>
        /// 判定文件是否打開
        /// </summary>   
        [DllImport("kernel32.dll")]
        public static extern IntPtr _lopen(string lpPathName, int iReadWrite);
        [DllImport("kernel32.dll")]
        public static extern bool CloseHandle(IntPtr hObject);
        public const int OF_READWRITE = 2;
        public const int OF_SHARE_DENY_NONE = 0x40;
        public readonly IntPtr HFILE_ERROR = new IntPtr(-1);

        /// <summary>
        /// 檢測文件被占用 
        /// </summary>
        /// <param name="FileNames">要檢測的文件路徑</param>
        /// <returns></returns>
        public bool CheckFiles(string FileNames)
        {
            if (!File.Exists(FileNames))
            {
                //文件不存在
                return true;
            }
            IntPtr vHandle = _lopen(FileNames, OF_READWRITE | OF_SHARE_DENY_NONE);
            if (vHandle == HFILE_ERROR)
            {
                //文件被占用
                return false;
            }
            //文件沒被占用
            CloseHandle(vHandle);
            return true;
        }
        #endregion                            
    }
}

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三、調用

private void btnExport_Click_1(object sender, EventArgs e)
{
	ExportDgvToExcel export = new ExportDgvToExcel();
	export.ExportExcel("", dgv, "宋體", 11);//默認文件名,DataGridView控件的名稱,字體,字號 
}