一、NPOI简介

1.1、NPOI是什么

NPOI是POI的.NET版本,POI是一套用Java写成的库，我们在开发中经常用到导入导出表格、文档的情况，NPOI能够帮助我们在没有安装微软Office的情况下读写Office文件，如xls, doc, ppt等。NPOI采用的是Apache 2.0许可证（poi也是采用这个许可证），这意味着它可以被用于任何商业或非商业项目，我们不用担心因为使用它而必须开放你自己的源代码，所以它对于很多从事业务系统开发的公司来说绝对是很不错的选择。

1.2、NPOI简单使用

NPOI的API十分人性化，使用起来非常容易上手。首先创建一个控制台应用程序，通过nuget获取NPOI，这里使用的是最新版本2.5.4，如下：

1.2.1、创建Excel的Sheet和给单元格添加数据【基础1】

//创建Sheet和给单元格添加数据【基础1】private void CreateSheetAndCell_BaseOne(string filePathAndName){if (string.IsNullOrEmpty(filePathAndName)) return;//创建workbook，说白了就是在内存中创建一个Excel文件IWorkbook workbook = new HSSFWorkbook();//要添加至少一个sheet,没有sheet的excel是打不开的ISheet sheet1 = workbook.CreateSheet("sheet1");ISheet sheet2 = workbook.CreateSheet("sheet2");IRow row1 = sheet1.CreateRow(0);//添加第1行,注意行列的索引都是从0开始的ICell cell1 = row1.CreateCell(0);//给第1行添加第1个单元格cell1.SetCellValue("hello npoi!");//给单元格赋值//上边3个步骤合在一起：sheet1.CreateRow(0).CreateCell(0).SetCellValue("hello npoi");//获取第一行第一列的string值Console.WriteLine(sheet1.GetRow(0).GetCell(0).StringCellValue); //输出：hello npoi//写入文件using (FileStream file = new FileStream(filePathAndName, FileMode.Create)){workbook.Write(file);}//导出成功提示ExportSuccessTips(filePathAndName);}

运行后在选择的路径创建对应的Excel文件且格式如下：

二、NPOI使用详解

2.1 单元格数据格式

用过Excel的人都知道，单元格是Excel最有意义的东西，我们做任何操作恐怕都要和单元格打交道。在Excel中我们经常要设置格式，比如说日期格式（-1-1）、小数点格式（1.20）、货币格式（$2000）、百分比格式（99.99%）等等，这些东西在过去我们恐怕只能在服务器端生成好，不但增加了服务器端的代码量，还造成了不必要的字符串替换操作，如今NPOI将让服务器从这种完全没有必要的操作中解放出来，一切都将由Excel在客户端处理。

使用NPOI时要注意，所有的格式都是通过CellStyle.DataFormat赋给单元格的，而不是直接赋给单元格，设置单元格数据展示的格式有两种方法。

2.1.1、设置excel中内置的格式：

excel内部设置了很多格式，如下图所示：

如果我们想使用这些内置的格式，可用通过DataFormat.GetBuildinFormat('格式')来使用，使用实例如下：

cellStyle.DataFormat = HSSFDataFormat.GetBuiltinFormat("0.00"); //两位小数，内置格式

2.1.2、设置自定义格式

有时候内置的格式不能满足我们的要求，这时候就可以使用workbook.CreateDataFormat().GetFormat("格式")自定义格式了，使用语法如下：

cellStyle.DataFormat= workbook.CreateDataFormat().GetFormat("yyyy年m月d日 hh时mm分ss秒");//显示中文日期和时间，自定义格式

//导出数据到Excel基础_单元格格式转换private void ExportExcel_CellFormat(string filePathAndName){if (string.IsNullOrEmpty(filePathAndName)) return;IWorkbook workbook = new HSSFWorkbook();ISheet sheet = workbook.CreateSheet("new sheet");//设置日期格式，5月5日格式ICell cell = sheet.CreateRow(0).CreateCell(0);cell.SetCellValue(new DateTime(, 5, 5, 11, 31, 56));ICellStyle cellStyle = workbook.CreateCellStyle();cellStyle.DataFormat = workbook.CreateDataFormat().GetFormat("yyyy年m月d日 hh时mm分ss秒");//cellStyle.DataFormat = workbook.CreateDataFormat().GetFormat("yyyy/mm/dd hh:mm:ss"); cell.CellStyle = cellStyle;//保留2位小数ICell cell2 = sheet.CreateRow(1).CreateCell(0);cell2.SetCellValue(12.346666);ICellStyle cellStyle2 = workbook.CreateCellStyle();cellStyle2.DataFormat = HSSFDataFormat.GetBuiltinFormat("0.00");cell2.CellStyle = cellStyle2;//货币格式ICell cell3 = sheet.CreateRow(2).CreateCell(0);cell3.SetCellValue(1234.66666);ICellStyle cellStyle3 = workbook.CreateCellStyle();cellStyle3.DataFormat = workbook.CreateDataFormat().GetFormat("￥#,##0.00");//美元的话格式为 $#,##0.00，其中#，##0表示千分号cell3.CellStyle = cellStyle3;//百分比ICell cell4 = sheet.CreateRow(3).CreateCell(0);cell4.SetCellValue(1.236666);ICellStyle cellStyle4 = workbook.CreateCellStyle();//cellStyle4.DataFormat = HSSFDataFormat.GetBuiltinFormat("0.00%");//保留两位小数cellStyle4.DataFormat = HSSFDataFormat.GetBuiltinFormat("0%");cell4.CellStyle = cellStyle4;//中文大写数字ICell cell5 = sheet.CreateRow(4).CreateCell(0);cell5.SetCellValue(111);ICellStyle cellStyle5 = workbook.CreateCellStyle();cellStyle5.DataFormat = workbook.CreateDataFormat().GetFormat("[DbNum2][$-804]0.00");//不保留小数： [DbNum2][$-804]0cell5.CellStyle = cellStyle5;//科学计数法ICell cell6 = sheet.CreateRow(5).CreateCell(0);cell6.SetCellValue(1234.6666);ICellStyle cellStyle6 = workbook.CreateCellStyle();cellStyle6.DataFormat = HSSFDataFormat.GetBuiltinFormat("0.00E+00");cell6.CellStyle = cellStyle6;using (FileStream file = new FileStream(filePathAndName, FileMode.Create)){workbook.Write(file);}//导出成功提示ExportSuccessTips(filePathAndName);}

运行程序生成的Excel文件效果如下：

2.2、单元格合并及设置风格

单元格的合并和风格这部分内容比较多，但是Api十分的简单，为了看起来清晰，我们分成两个栗子来演示这部分的功能，代码中的注释很详细，这里就直接上代码了

2.2.1、第一个栗子演示单元格合并，内容停靠，字体风格颜色大小等

//导出数据到Excel基础_单元格合并及风格设置1private void ExportExcel_MergeCellStyleSettingsOne(string filePathAndName){if (string.IsNullOrEmpty(filePathAndName)) return;HSSFWorkbook workbook = new HSSFWorkbook();ISheet sheet = workbook.CreateSheet("sheet1");//------------------单元格合并sheet.AddMergedRegion(new CellRangeAddress(1, 2, 1, 5));//合并单元格,4个参数依次为为startRow,endRow,startCol,endColICell cell = sheet.CreateRow(1).CreateCell(1);cell.SetCellValue("合并的区域");cell.Row.HeightInPoints = 40;//行高ICellStyle cellstyle = workbook.CreateCellStyle();//----------------设置单元格常用风格cellstyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Left;//水平居左，可选Right,Centercellstyle.VerticalAlignment = VerticalAlignment.Bottom;//垂直居中,可选Top,Centercellstyle.WrapText = true;//自动换行cellstyle.Indention = 4;//缩进4个字节//cellstyle.Rotation = 90;//字体旋转90度，取值范围是[-90,90]//---------------字体，字体大小、颜色IFont font = workbook.CreateFont();font.FontHeightInPoints = 24;//字号为24，可以用font.FontHeight = 24 * 20;FontHeight的单位是1/20点font.FontName = "幼圆";//字体font.Boldweight = 700;//加粗font.Color = HSSFColor.Blue.Index;//字体颜色cellstyle.SetFont(font);cell.CellStyle = cellstyle;using (FileStream file = new FileStream(filePathAndName, FileMode.Create)){workbook.Write(file);}//导出成功提示ExportSuccessTips(filePathAndName);}

生成的excel文件如下图所示：

2.2.2、第二个栗子演示单元格的宽高、背景色、边框风格等

//导出数据到Excel基础_单元格合并及风格设置2private void ExportExcel_MergeCellStyleSettingsTwo(string filePathAndName){if (string.IsNullOrEmpty(filePathAndName)) return;IWorkbook workbook = new HSSFWorkbook();ISheet sheet = workbook.CreateSheet("sheet1");ICell cell = sheet.CreateRow(1).CreateCell(1);cell.SetCellValue("hello");ICellStyle cellstyle = workbook.CreateCellStyle();//设置宽度，把第2列设成20字节宽；参数1指定列的索引；参数2指定宽度，单位是1/256个字符宽度sheet.SetColumnWidth(1, 20 * 256);//高度设成40，单位是点；也可以用cell2.Row.Height = 40 * 20;Height的单位是1/20点cell.Row.HeightInPoints = 40;//右边框设置成点画线cellstyle.BorderRight = NPOI.SS.UserModel.BorderStyle.MediumDashDot;//右边框设成粉色cellstyle.RightBorderColor = HSSFColor.Pink.Index;//前景色填充模式，实心cellstyle.FillPattern = FillPattern.SolidForeground;//前景色填充颜色，黄色cellstyle.FillForegroundColor = HSSFColor.Yellow.Index;//背景色//cellstyle2.FillBackgroundColor = HSSFColor.Green.Index;//背景色设成greencell.CellStyle = cellstyle;using (FileStream file = new FileStream(filePathAndName, FileMode.Create)){workbook.Write(file);}//导出成功提示ExportSuccessTips(filePathAndName);}

运行程序，生成的excel文件如下：

其实在NPOI中除了操作单元格的内容和风格外，还提供了添加excel文件摘要，添加批注，画图，使用公式等功能，但是这些功能我们用的比较少，所以就不一一展示了，NPOI的公式我自己很少去使用，一般通过程序直接计算结果，个人感觉在程序中计算更加灵活，当excel的结构发生变化时修改起来也更方便些。

三、封装的ExcelHelper帮助类

3.1、使用ExcelHelper帮助类导出文件

使用Nuget添加几个包：NPOI，log4net(其他的日志记录组件也可以)，System.Text.Encoding.CodePages(为了支持gb2312)，具体代码如下：

//导出数据到Excelprivate void ExportExcel(string filePathAndName){if (string.IsNullOrEmpty(filePathAndName)) return;//用于支持gb2312 Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);//测试dataTable数据源 DataTable dataTable = new DataTable();dataTable.Columns.Add("id", typeof(int));dataTable.Columns.Add("uname", typeof(string));dataTable.Columns.Add("sex", typeof(string));dataTable.Columns.Add("age", typeof(int));dataTable.Columns.Add("pwd", typeof(string));dataTable.Columns.Add("email", typeof(string));dataTable.Columns.Add("address", typeof(string));Random r = new Random();for (int i = 0; i < 1000; i++){DataRow row = dataTable.NewRow();row["id"] = i;row["uname"] = "hellox" + i.ToString();row["sex"] = r.Next(2) % 2 == 0 ? "男" : "女";row["age"] = r.Next(40) + 18;row["pwd"] = "pwd" + r.Next(5000).ToString();row["email"] = r.Next(100000) + "@";row["address"] = $"北京市，西{r.Next(4) + 1}环，xx路{r.Next(100)}号";dataTable.Rows.Add(row);}//DataTable的列名和excel的列名对应字典，因为excel的列名一般是中文的，DataTable的列名是英文的，字典主要是存储excel和DataTable列明的对应关系，当然我们也可以把这个对应关系存在配置文件或者其他地方Dictionary<string, string> dir = new Dictionary<string, string>();dir.Add("id", "编号");dir.Add("uname", "用户");dir.Add("sex", "性别");dir.Add("age", "年龄");dir.Add("pwd", "密码");dir.Add("email", "邮箱");dir.Add("address", "住址");//使用helper类导出DataTable数据到excel表格中,参数依次是 （DataTable数据源; excel表名; excel存放位置的绝对路径; 列名对应字典; 是否清空以前的数据，设置为false，表示内容追加; 每个sheet放的数据条数,如果超过该条数就会新建一个sheet存储）ExcelHelper.ExportDTtoExcel(dataTable, "考勤信息表", filePathAndName, dir, false, 400);//导出成功提示ExportSuccessTips(filePathAndName);}

运行程序，当一个sheet的数目满了后会新生产一个sheet1来存储，效果如下：

3.2、使用ExcelHelper帮助类导入文件

//从Excel中导入数据到界面private void ImportUIfFromExcel(string filePathAndName){if (string.IsNullOrEmpty(filePathAndName)) return;//用于支持gb2312 Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);//DataTable的列名和excel的列名对应字典Dictionary<string, string> dir = new Dictionary<string, string>();dir.Add("id", "编号");dir.Add("uname", "用户");dir.Add("sex", "性别");dir.Add("age", "年龄");dir.Add("pwd", "密码");dir.Add("email", "邮箱");dir.Add("address", "住址");//读取数据到DataTable，参数依此是（excel文件路径，列名对应字典，列名所在行，sheet索引）DataTable dt = ExcelHelper.ImportExceltoDt(filePathAndName, dir, 1, 0);//遍历DataTable---------------------------string tmpInfo = null;foreach (DataColumn item in dt.Columns){//显示dataTable的列名tmpInfo+=(item.ColumnName + new string('-', 10));}tmpInfo += "\r\n";//遍历DataTable中的数据foreach (DataRow row in dt.Rows){for (int i = 0; i < dt.Columns.Count; i++){tmpInfo+=(row[i].ToString() + new string(' ', 10));}tmpInfo += "\r\n";}//显示数据ShowInfo(tmpInfo);//导入成功提示ImportSuccessTips(filePathAndName);}

运行程序后的效果如下：

3.3、ExcelHelper帮助类

兼容xls和xlsx两种格式

/****Title："基础工具" 项目*主题：Excel帮助类*Description：*功能：* 1、导出数据到Excel文件中* 2、将Excel文件的数据导入到DataTable中*Date：*Version：0.1版本*Author：Coffee*Modify Recoder：*/using System;using System.Collections.Generic;using System.Data;using System.IO;using System.Text;using NPOI.HSSF.UserModel;using NPOI.SS.Formula.Eval;using NPOI.SS.UserModel;using System.Linq;using NPOI.SS.Util;using System.Text.RegularExpressions;using NPOI.XSSF.UserModel;namespace Utils{public class ExcelHelper{#region 从DataTable导出到excel文件中，支持xls和xlsx格式#region 导出为xls文件内部方法/// <summary>/// 从datatable 中导出到excel/// </summary>/// <param name="strFileName">excel文件名</param>/// <param name="dtSource">datatabe源数据</param>/// <param name="strHeaderText">表名</param>/// <param name="sheetnum">sheet的编号</param>/// <returns></returns>static MemoryStream ExportDT(String strFileName, DataTable dtSource, string strHeaderText, Dictionary<string, string> dir, int sheetnum){//创建工作簿和sheetIWorkbook workbook = new HSSFWorkbook();using (Stream writefile = new FileStream(strFileName, FileMode.OpenOrCreate, FileAccess.Read)){if (writefile.Length > 0 && sheetnum > 0){workbook = WorkbookFactory.Create(writefile);}}ISheet sheet = null;ICellStyle dateStyle = workbook.CreateCellStyle();IDataFormat format = workbook.CreateDataFormat();dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");int[] arrColWidth = new int[dtSource.Columns.Count];foreach (DataColumn item in dtSource.Columns){arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;}for (int i = 0; i < dtSource.Rows.Count; i++){for (int j = 0; j < dtSource.Columns.Count; j++){int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][j].ToString()).Length;if (intTemp > arrColWidth[j]){arrColWidth[j] = intTemp;}}}int rowIndex = 0;foreach (DataRow row in dtSource.Rows){#region 新建表，填充表头，填充列头，样式if (rowIndex == 0){string sheetName = strHeaderText + (sheetnum == 0 ? "" : sheetnum.ToString());if (workbook.GetSheetIndex(sheetName) >= 0){workbook.RemoveSheetAt(workbook.GetSheetIndex(sheetName));}sheet = workbook.CreateSheet(sheetName);#region 表头及样式{sheet.AddMergedRegion(new CellRangeAddress(0, 0, 0, dtSource.Columns.Count - 1));IRow headerRow = sheet.CreateRow(0);headerRow.HeightInPoints = 25;headerRow.CreateCell(0).SetCellValue(strHeaderText);ICellStyle headStyle = workbook.CreateCellStyle();headStyle.Alignment = HorizontalAlignment.Center;IFont font = workbook.CreateFont();font.FontHeightInPoints = 20;font.Boldweight = 700;headStyle.SetFont(font);headerRow.GetCell(0).CellStyle = headStyle;rowIndex = 1;}#endregion#region 列头及样式if (rowIndex == 1){IRow headerRow = sheet.CreateRow(1);//第二行设置列名ICellStyle headStyle = workbook.CreateCellStyle();headStyle.Alignment = HorizontalAlignment.Center;IFont font = workbook.CreateFont();font.FontHeightInPoints = 10;font.Boldweight = 700;headStyle.SetFont(font);//写入列标题foreach (DataColumn column in dtSource.Columns){headerRow.CreateCell(column.Ordinal).SetCellValue(dir[column.ColumnName]);headerRow.GetCell(column.Ordinal).CellStyle = headStyle;//设置列宽sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256 * 2);}rowIndex = 2;}#endregion}#endregion#region 填充内容IRow dataRow = sheet.CreateRow(rowIndex);foreach (DataColumn column in dtSource.Columns){ICell newCell = dataRow.CreateCell(column.Ordinal);string drValue = row[column].ToString();switch (column.DataType.ToString()){case "System.String": //字符串类型double result;if (isNumeric(drValue, out result)){//数字字符串double.TryParse(drValue, out result);newCell.SetCellValue(result);break;}else{newCell.SetCellValue(drValue);break;}case "System.DateTime": //日期类型DateTime dateV;DateTime.TryParse(drValue, out dateV);newCell.SetCellValue(dateV);newCell.CellStyle = dateStyle; //格式化显示break;case "System.Boolean": //布尔型bool boolV = false;bool.TryParse(drValue, out boolV);newCell.SetCellValue(boolV);break;case "System.Int16": //整型case "System.Int32":case "System.Int64":case "System.Byte":int intV = 0;int.TryParse(drValue, out intV);newCell.SetCellValue(intV);break;case "System.Decimal": //浮点型case "System.Double":double doubV = 0;double.TryParse(drValue, out doubV);newCell.SetCellValue(doubV);break;case "System.DBNull": //空值处理newCell.SetCellValue("");break;default:newCell.SetCellValue(drValue.ToString());break;}}#endregionrowIndex++;}using (MemoryStream ms = new MemoryStream()){workbook.Write(ms);ms.Flush();ms.Position = 0;return ms;}}#endregion#region 导出为xlsx文件内部方法/// <summary>/// 从datatable 中导出到excel/// </summary>/// <param name="dtSource">datatable数据源</param>/// <param name="strHeaderText">表名</param>/// <param name="fs">文件流</param>/// <param name="readfs">内存流</param>/// <param name="sheetnum">sheet索引</param>static void ExportDTI(DataTable dtSource, string strHeaderText, FileStream fs, MemoryStream readfs, Dictionary<string, string> dir, int sheetnum){IWorkbook workbook = new XSSFWorkbook();if (readfs.Length > 0 && sheetnum > 0){workbook = WorkbookFactory.Create(readfs);}ISheet sheet = null;ICellStyle dateStyle = workbook.CreateCellStyle();IDataFormat format = workbook.CreateDataFormat();dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");//取得列宽int[] arrColWidth = new int[dtSource.Columns.Count];foreach (DataColumn item in dtSource.Columns){arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;}for (int i = 0; i < dtSource.Rows.Count; i++){for (int j = 0; j < dtSource.Columns.Count; j++){int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][j].ToString()).Length;if (intTemp > arrColWidth[j]){arrColWidth[j] = intTemp;}}}int rowIndex = 0;foreach (DataRow row in dtSource.Rows){#region 新建表，填充表头，填充列头，样式if (rowIndex == 0){#region 表头及样式{string sheetName = strHeaderText + (sheetnum == 0 ? "" : sheetnum.ToString());if (workbook.GetSheetIndex(sheetName) >= 0){workbook.RemoveSheetAt(workbook.GetSheetIndex(sheetName));}sheet = workbook.CreateSheet(sheetName);sheet.AddMergedRegion(new CellRangeAddress(0, 0, 0, dtSource.Columns.Count - 1));IRow headerRow = sheet.CreateRow(0);headerRow.HeightInPoints = 25;headerRow.CreateCell(0).SetCellValue(strHeaderText);ICellStyle headStyle = workbook.CreateCellStyle();headStyle.Alignment = HorizontalAlignment.Center;IFont font = workbook.CreateFont();font.FontHeightInPoints = 20;font.Boldweight = 700;headStyle.SetFont(font);headerRow.GetCell(0).CellStyle = headStyle;}#endregion#region 列头及样式{IRow headerRow = sheet.CreateRow(1);ICellStyle headStyle = workbook.CreateCellStyle();headStyle.Alignment = HorizontalAlignment.Center;IFont font = workbook.CreateFont();font.FontHeightInPoints = 10;font.Boldweight = 700;headStyle.SetFont(font);foreach (DataColumn column in dtSource.Columns){headerRow.CreateCell(column.Ordinal).SetCellValue(dir[column.ColumnName]);headerRow.GetCell(column.Ordinal).CellStyle = headStyle;//设置列宽sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256 * 2);}}#endregionrowIndex = 2;}#endregion#region 填充内容IRow dataRow = sheet.CreateRow(rowIndex);foreach (DataColumn column in dtSource.Columns){ICell newCell = dataRow.CreateCell(column.Ordinal);string drValue = row[column].ToString();switch (column.DataType.ToString()){case "System.String": //字符串类型double result;if (isNumeric(drValue, out result)){double.TryParse(drValue, out result);newCell.SetCellValue(result);break;}else{newCell.SetCellValue(drValue);break;}case "System.DateTime": //日期类型DateTime dateV;DateTime.TryParse(drValue, out dateV);newCell.SetCellValue(dateV);newCell.CellStyle = dateStyle; //格式化显示break;case "System.Boolean": //布尔型bool boolV = false;bool.TryParse(drValue, out boolV);newCell.SetCellValue(boolV);break;case "System.Int16": //整型case "System.Int32":case "System.Int64":case "System.Byte":int intV = 0;int.TryParse(drValue, out intV);newCell.SetCellValue(intV);break;case "System.Decimal": //浮点型case "System.Double":double doubV = 0;double.TryParse(drValue, out doubV);newCell.SetCellValue(doubV);break;case "System.DBNull": //空值处理newCell.SetCellValue("");break;default:newCell.SetCellValue(drValue.ToString());break;}}#endregionrowIndex++;}workbook.Write(fs);fs.Close();}#endregion#region 导出excel表格/// <summary>/// DataTable导出到Excel文件，xls文件/// </summary>/// <param name="dtSource">数据源</param>/// <param name="strHeaderText">表名</param>/// <param name="strFileName">excel文件名</param>/// <param name="dir">datatable和excel列名对应字典</param>/// <param name="sheetRow">每个sheet存放的行数</param>public static void ExportDTtoExcel(DataTable dtSource, string strHeaderText, string strFileName, Dictionary<string, string> dir, bool isNew, int sheetRow = 50000){int currentSheetCount = GetSheetNumber(strFileName);//现有的页数sheetnumif (sheetRow <= 0){sheetRow = dtSource.Rows.Count;}string[] temp = strFileName.Split('.');string fileExtens = temp[temp.Length - 1];int sheetCount = (int)Math.Ceiling((double)dtSource.Rows.Count / sheetRow);//sheet数目if (temp[temp.Length - 1] == "xls" && dtSource.Columns.Count < 256 && sheetRow < 65536){if (isNew){currentSheetCount = 0;}for (int i = currentSheetCount; i < currentSheetCount + sheetCount; i++){DataTable pageDataTable = dtSource.Clone();int hasRowCount = dtSource.Rows.Count - sheetRow * (i - currentSheetCount) < sheetRow ? dtSource.Rows.Count - sheetRow * (i - currentSheetCount) : sheetRow;for (int j = 0; j < hasRowCount; j++){pageDataTable.ImportRow(dtSource.Rows[(i - currentSheetCount) * sheetRow + j]);}using (MemoryStream ms = ExportDT(strFileName, pageDataTable, strHeaderText, dir, i)){using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write)){byte[] data = ms.ToArray();fs.Write(data, 0, data.Length);fs.Flush();}}}}else{if (temp[temp.Length - 1] == "xls")strFileName = strFileName + "x";if (isNew){currentSheetCount = 0;}for (int i = currentSheetCount; i < currentSheetCount + sheetCount; i++){DataTable pageDataTable = dtSource.Clone();int hasRowCount = dtSource.Rows.Count - sheetRow * (i - currentSheetCount) < sheetRow ? dtSource.Rows.Count - sheetRow * (i - currentSheetCount) : sheetRow;for (int j = 0; j < hasRowCount; j++){pageDataTable.ImportRow(dtSource.Rows[(i - currentSheetCount) * sheetRow + j]);}FileStream readfs = new FileStream(strFileName, FileMode.OpenOrCreate, FileAccess.Read);MemoryStream readfsm = new MemoryStream();readfs.CopyTo(readfsm);readfs.Close();using (FileStream writefs = new FileStream(strFileName, FileMode.Create, FileAccess.Write)){ExportDTI(pageDataTable, strHeaderText, writefs, readfsm, dir, i);}readfsm.Close();}}}#endregion#endregion#region 从excel文件中将数据导出到datatable/datatable/// <summary>/// 将制定sheet中的数据导出到datatable中/// </summary>/// <param name="sheet">需要导出的sheet</param>/// <param name="HeaderRowIndex">列头所在行号，-1表示没有列头</param>/// <param name="dir">excel列名和DataTable列名的对应字典</param>/// <returns></returns>static DataTable ImportDt(ISheet sheet, int HeaderRowIndex, Dictionary<string, string> dir){DataTable table = new DataTable();IRow headerRow;int cellCount;try{//没有标头或者不需要表头用excel列的序号（1,2,3..）作为DataTable的列名if (HeaderRowIndex < 0){headerRow = sheet.GetRow(0);cellCount = headerRow.LastCellNum;for (int i = headerRow.FirstCellNum; i <= cellCount; i++){DataColumn column = new DataColumn(Convert.ToString(i));table.Columns.Add(column);}}//有表头，使用表头做为DataTable的列名else{headerRow = sheet.GetRow(HeaderRowIndex);cellCount = headerRow.LastCellNum;for (int i = headerRow.FirstCellNum; i <= cellCount; i++){//如果excel某一列列名不存在：以该列的序号作为Datatable的列名，如果DataTable中包含了这个序列为名的列，那么列名为重复列名+序号if (headerRow.GetCell(i) == null){if (table.Columns.IndexOf(Convert.ToString(i)) > 0){DataColumn column = new DataColumn(Convert.ToString("重复列名" + i));table.Columns.Add(column);}else{DataColumn column = new DataColumn(Convert.ToString(i));table.Columns.Add(column);}}//excel中的某一列列名不为空，但是重复了：对应的Datatable列名为“重复列名+序号”else if (table.Columns.IndexOf(headerRow.GetCell(i).ToString()) > 0){DataColumn column = new DataColumn(Convert.ToString("重复列名" + i));table.Columns.Add(column);}else//正常情况，列名存在且不重复：用excel中的列名作为datatable中对应的列名{string colName = dir.Where(s => s.Value == headerRow.GetCell(i).ToString()).First().Key;DataColumn column = new DataColumn(colName);table.Columns.Add(column);}}}int rowCount = sheet.LastRowNum;for (int i = (HeaderRowIndex + 1); i <= sheet.LastRowNum; i++)//excel行遍历{try{IRow row;if (sheet.GetRow(i) == null)//如果excel有空行，则添加缺失的行{row = sheet.CreateRow(i);}else{row = sheet.GetRow(i);}DataRow dataRow = table.NewRow();for (int j = row.FirstCellNum; j <= cellCount; j++)//excel列遍历{try{if (row.GetCell(j) != null){switch (row.GetCell(j).CellType){case CellType.String://字符串string str = row.GetCell(j).StringCellValue;if (str != null && str.Length > 0){dataRow[j] = str.ToString();}else{dataRow[j] = default(string);}break;case CellType.Numeric://数字if (DateUtil.IsCellDateFormatted(row.GetCell(j)))//时间戳数字{dataRow[j] = DateTime.FromOADate(row.GetCell(j).NumericCellValue);}else{dataRow[j] = Convert.ToDouble(row.GetCell(j).NumericCellValue);}break;case CellType.Boolean:dataRow[j] = Convert.ToString(row.GetCell(j).BooleanCellValue);break;case CellType.Error:dataRow[j] = ErrorEval.GetText(row.GetCell(j).ErrorCellValue);break;case CellType.Formula://公式switch (row.GetCell(j).CachedFormulaResultType){case CellType.String:string strFORMULA = row.GetCell(j).StringCellValue;if (strFORMULA != null && strFORMULA.Length > 0){dataRow[j] = strFORMULA.ToString();}else{dataRow[j] = null;}break;case CellType.Numeric:dataRow[j] = Convert.ToString(row.GetCell(j).NumericCellValue);break;case CellType.Boolean:dataRow[j] = Convert.ToString(row.GetCell(j).BooleanCellValue);break;case CellType.Error:dataRow[j] = ErrorEval.GetText(row.GetCell(j).ErrorCellValue);break;default:dataRow[j] = "";break;}break;default:dataRow[j] = "";break;}}}catch (Exception exception){//loger.Error(exception.ToString());}}table.Rows.Add(dataRow);}catch (Exception exception){//loger.Error(exception.ToString());}}}catch (Exception exception){//loger.Error(exception.ToString());}return table;}/// <summary>/// 读取Excel文件特定名字sheet的内容到DataTable/// </summary>/// <param name="strFileName">excel文件路径</param>/// <param name="sheet">需要导出的sheet</param>/// <param name="HeaderRowIndex">列头所在行号，-1表示没有列头</param>/// <param name="dir">excel列名和DataTable列名的对应字典</param>/// <returns></returns>public static DataTable ImportExceltoDt(string strFileName, Dictionary<string, string> dir, string SheetName, int HeaderRowIndex = 1){DataTable table = new DataTable();using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read)){if (file.Length > 0){IWorkbook wb = WorkbookFactory.Create(file);ISheet isheet = wb.GetSheet(SheetName);table = ImportDt(isheet, HeaderRowIndex, dir);isheet = null;}}return table;}/// <summary>/// 读取Excel文件某一索引sheet的内容到DataTable/// </summary>/// <param name="strFileName">excel文件路径</param>/// <param name="sheet">需要导出的sheet序号</param>/// <param name="HeaderRowIndex">列头所在行号，-1表示没有列头</param>/// <param name="dir">excel列名和DataTable列名的对应字典</param>/// <returns></returns>public static DataTable ImportExceltoDt(string strFileName, Dictionary<string, string> dir, int HeaderRowIndex = 1, int SheetIndex = 0){DataTable table = new DataTable();using (FileStream file = new FileStream(strFileName, FileMode.Open, FileAccess.Read)){if (file.Length > 0){IWorkbook wb = WorkbookFactory.Create(file);ISheet isheet = wb.GetSheetAt(SheetIndex);table = ImportDt(isheet, HeaderRowIndex, dir);isheet = null;}}return table;}#endregion/// <summary>/// 获取excel文件的sheet数目/// </summary>/// <param name="outputFile"></param>/// <returns></returns>public static int GetSheetNumber(string outputFile){int number = 0;using (FileStream readfile = new FileStream(outputFile, FileMode.OpenOrCreate, FileAccess.Read)){if (readfile.Length > 0){IWorkbook wb = WorkbookFactory.Create(readfile);number = wb.NumberOfSheets;}}return number;}/// <summary>/// 判断内容是否是数字/// </summary>/// <param name="message"></param>/// <param name="result"></param>/// <returns></returns>public static bool isNumeric(String message, out double result){Regex rex = new Regex(@"^[-]?\d+[.]?\d*$");result = -1;if (rex.IsMatch(message)){result = double.Parse(message);return true;}elsereturn false;}/// <summary>/// 验证导入的Excel是否有数据/// </summary>/// <param name="excelFileStream"></param>/// <returns></returns>public static bool HasData(Stream excelFileStream){using (excelFileStream){IWorkbook workBook = new HSSFWorkbook(excelFileStream);if (workBook.NumberOfSheets > 0){ISheet sheet = workBook.GetSheetAt(0);return sheet.PhysicalNumberOfRows > 0;}}return false;}}//Class_end}

3.4、导入导出提示

//导出成功提示private void ExportSuccessTips(string filePathAndName){if (string.IsNullOrEmpty(filePathAndName)) return;MessageBox.Show("导出成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);if (MessageBox.Show("保存成功，是否打开文件？", "提示", MessageBoxButtons.YesNo, MessageBoxIcon.Information) == DialogResult.Yes){System.Diagnostics.Process.Start(filePathAndName);}}//导入成功提示private void ImportSuccessTips(string filePathAndName){if (string.IsNullOrEmpty(filePathAndName)) return;MessageBox.Show("导入成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);}//信息提示private void ShowInfo(string info){memoEdit1.Text = info;}

3.5、Winform中获取选择的目录、文件的路径和名称

Winform中获取选择的目录、文件的路径和名称