EXCEL终极总结分享基于NPOI扩展封装的简易操作工具类库（简单灵活易用，支持导出导入上传等常见操作）

Posted 2021-12-28 zuowj

对于EXCEL的导入、导出，我之前已分享过多次，比如：

第一种方案：《我写的一个ExcelHelper通用类，可用于读取或生成数据》这个主要是利用把EXCEL当成一个DB来进行获取数据，导出则是采用拼接成html TABLE的方式，这种在ASP.NET，ASP.NET CORE 中也是可以的，简单方便，依赖Office Excel组件，仅适用于网站服务端。 推荐指数：♥♥♥

第二种方案：《MVC导出数据到EXCEL新方法：将视图或分部视图转换为HTML后再直接返回FileResult》这个主要是实现导出EXCEL的方法，依赖MVC框架，利用视图引擎解析渲染View（view也主要是HTML表格模板）获得HTML TABLE，本质与第一种的导出相同，只是这里不用代码去拼接HTML TABLE而是写View HTML模板即可，简单方便，适用于ASP.NET MVC、ASP.NET MVC CORE； 推荐指数：♥♥♥♥

第三种方案：《NPOI导入导出EXCEL通用类，供参考，可直接使用在WinForm项目中》这个实现了EXCEL的导入、导出方法，依赖NPOI，优点是：无需安装EXCEL也能操作EXCEL，文中的实现方案及示例主要是用在C/S中，对B/S 支持不够友好，当然可以进行适当修改就能兼容WEB版。推荐指数：♥♥♥♥

第四种方案：《分享我基于NPOI+ExcelReport实现的导入与导出EXCEL类库》这个完美的灵活实现了EXCEL的各种导入、导出方法，支持基于模板导出，格式自定义等 特点，依赖：ExcelReport、NPOI、NPOI.Extend，支持C/S、B/S（C/S特有的方法除外），适用于企业级EXCEL操作比较复杂的场景：ExcelUtility，推荐指数：♥♥♥♥♥，git地址：https://gitee.com/zuowj/ExcelUtility

第五种方案：就是本文即将介绍的，依赖NPOI，实现EXCEL的导入、导出、上传等常见方法，充分借鉴第三种、第四种方案，抽出核心的实现方法，并进行适当改造，以满足绝大部份的EXCEL场景，轻量、简单、易用，支持链式操作，类库名：ExcelEasyUtil，故名思义：EXCEL简单实用工具类库。

该类库主要是基于NPOI的IWorkbook进行扩展，扩展方法实现了常见的几种导出EXCEL、导入EXCEL数据的方法：基于类型集合，基于DataTable，NPOIExtensions完整实现代码如下：

 

using Newtonsoft.Json.Linq;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq.Expressions;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Reflection;
using System.Text;

namespace ExcelEasyUtil


    /// <summary>
    /// NPOI扩展类
    /// author:zuowenjun 
    /// 2019-5-21
    /// </summary>
    public static class NPOIExtensions
    
        /// <summary>
        /// 将一个实体数据对象填充到一个EXCEL工作表中(可连续填充多个sheet，如：FillSheet(...).FillSheet(..) )
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="book"></param>
        /// <param name="sheetName"></param>
        /// <param name="headerColNames"></param>
        /// <param name="excelData"></param>
        /// <param name="getCellValueFunc"></param>
        /// <returns></returns>
        public static IWorkbook FillSheet<T>(this IWorkbook book, string sheetName, IList<T> excelData,
            IList<string> headerColNames, Func<T, List<object>> getCellValuesFunc, IDictionary<string, string> colDataFormats = null) where T : class
        
            var sheet = book.CreateSheet(sheetName);

            IRow rowHeader = sheet.CreateRow(0);
            var headerCellStyle = GetCellStyle(book, true);
            Dictionary<int, ICellStyle> colStyles = new Dictionary<int, ICellStyle>();
            List<Type> colTypes = new List<Type>();
            Type strType = typeof(string);
            for (int i = 0; i < headerColNames.Count; i++)
            
                ICell headerCell = rowHeader.CreateCell(i);
                headerCell.CellStyle = headerCellStyle;

                string colName = headerColNames[i];

                if (colName.Contains(":"))
                
                    var colInfos = colName.Split(‘:‘);
                    colName = colInfos[0];
                    colTypes.Add(GetColType(colInfos[1]));
                
                else
                
                    colTypes.Add(strType);
                

                headerCell.SetCellValue(colName);
                if (colDataFormats != null && colDataFormats.ContainsKey(colName))
                
                    colStyles[i] = GetCellStyleWithDataFormat(book, colDataFormats[colName]);
                
                else
                
                    colStyles[i] = GetCellStyle(book);
                
            

            //生成excel内容
            for (int i = 0; i < excelData.Count; i++)
            
                IRow irow = sheet.CreateRow(i + 1);
                var row = excelData[i];
                var cellValues = getCellValuesFunc(row);
                for (int j = 0; j < headerColNames.Count; j++)
                
                    ICell cell = irow.CreateCell(j);
                    string cellValue = string.Empty;
                    if (cellValues.Count - 1 >= j && cellValues[j] != null)
                    
                        cellValue = cellValues[j].ToString();
                    

                    SetCellValue(cell, cellValue, colTypes[j], colStyles);
                
            

            return book;
        

        /// <summary>
        ///  将一个实体数据对象填充到一个EXCEL工作表中(可连续填充多个sheet，如：FillSheet(...).FillSheet(..) )
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="book"></param>
        /// <param name="sheetName"></param>
        /// <param name="colMaps"></param>
        /// <param name="excelData"></param>
        /// <returns></returns>
        public static IWorkbook FillSheet<T>(this IWorkbook book, string sheetName, IList<T> excelData,
                IDictionary<string, Expression<Func<T, dynamic>>> colMaps, IDictionary<string, string> colDataFormats = null
            ) where T : class
        

            var sheet = book.CreateSheet(sheetName);

            var headerColNames = new List<string>();
            var propInfos = new List<PropertyInfo>();

            foreach (var item in colMaps)
            
                headerColNames.Add(item.Key);
                var propInfo = GetPropertyInfo(item.Value);
                propInfos.Add(propInfo);
            

            var headerCellStyle = GetCellStyle(book, true);
            Dictionary<int, ICellStyle> colStyles = new Dictionary<int, ICellStyle>();
            IRow rowHeader = sheet.CreateRow(0);
            for (int i = 0; i < headerColNames.Count; i++)
            
                ICell headerCell = rowHeader.CreateCell(i);
                headerCell.CellStyle = headerCellStyle;
                headerCell.SetCellValue(headerColNames[i]);

                if (colDataFormats != null && colDataFormats.ContainsKey(headerColNames[i]))
                
                    colStyles[i] = GetCellStyleWithDataFormat(book, colDataFormats[headerColNames[i]]);
                
                else
                
                    colStyles[i] = GetCellStyle(book);
                
            

            //生成excel内容
            for (int i = 0; i < excelData.Count; i++)
            
                IRow irow = sheet.CreateRow(i + 1);
                var row = excelData[i];
                for (int j = 0; j < headerColNames.Count; j++)
                
                    var prop = propInfos[j];

                    ICell cell = irow.CreateCell(j);
                    string cellValue = Convert.ToString(propInfos[j].GetValue(row, null));
                    SetCellValue(cell, cellValue, prop.PropertyType, colStyles);
                
            

            return book;
        

        /// <summary>
        /// 将一个数据表（DataTable）对象填充到一个EXCEL工作表中(可连续填充多个sheet，如：FillSheet(...).FillSheet(..) )
        /// </summary>
        /// <param name="book"></param>
        /// <param name="sheetName"></param>
        /// <param name="excelData"></param>
        /// <param name="colMaps"></param>
        /// <param name="colDataFormats"></param>
        /// <returns></returns>
        public static IWorkbook FillSheet(this IWorkbook book, string sheetName, DataTable excelData, IDictionary<string, string> colMaps,
            IDictionary<string, string> colDataFormats = null)
        

            if (excelData.Rows.Count <= 0) return book;

            var sheet = book.CreateSheet(sheetName);


            var headerCellStyle = GetCellStyle(book, true);
            Dictionary<int, ICellStyle> colStyles = new Dictionary<int, ICellStyle>();
            IRow rowHeader = sheet.CreateRow(0);

            int nIndex = 0;
            var headerColNames = new List<string>();

            foreach (var item in colMaps)
            
                ICell headerCell = rowHeader.CreateCell(nIndex);
                headerCell.SetCellValue(item.Value);
                headerCell.CellStyle = headerCellStyle;

                if (colDataFormats != null && colDataFormats.ContainsKey(item.Value))
                
                    colStyles[nIndex] = GetCellStyleWithDataFormat(book, colDataFormats[item.Value]);
                
                else
                
                    colStyles[nIndex] = GetCellStyle(book);
                
                headerColNames.Add(item.Key);
                nIndex++;
            

            //生成excel内容
            for (int i = 0; i < excelData.Rows.Count; i++)
            
                IRow irow = sheet.CreateRow(i + 1);
                var row = excelData.Rows[i];
                for (int j = 0; j < headerColNames.Count; j++)
                
                    ICell cell = irow.CreateCell(j);
                    string colName = headerColNames[j];
                    string cellValue = row[colName].ToNotNullString();
                    SetCellValue(cell, cellValue, excelData.Columns[colName].DataType, colStyles);
                
            

            return book;
        

        private static PropertyInfo GetPropertyInfo<T, TR>(Expression<Func<T, TR>> select)
        
            var body = select.Body;
            if (body.NodeType == ExpressionType.Convert)
            
                var o = (body as UnaryExpression).Operand;
                return (o as MemberExpression).Member as PropertyInfo;
            
            else if (body.NodeType == ExpressionType.MemberAccess)
            
                return (body as MemberExpression).Member as PropertyInfo;
            
            return null;
        

        private static Type GetColType(string colTypeSimpleName)
        
            colTypeSimpleName = colTypeSimpleName.ToUpper();
            switch (colTypeSimpleName)
            
                case "DT":
                    
                        return typeof(DateTime);
                    
                case "BL":
                    
                        return typeof(Boolean);
                    
                case "NUM":
                    
                        return typeof(Int64);
                    
                case "DEC":
                    
                        return typeof(Decimal);
                    
                default:
                    
                        return typeof(String);
                    
            
        


        private static void SetCellValue(ICell cell, string value, Type colType, IDictionary<int, ICellStyle> colStyles)
        
            if (colType.IsNullableType())
            
                colType = colType.GetGenericArguments()[0];
            

            string dataFormatStr = null;
            switch (colType.ToString())
            
                case "System.String": //字符串类型
                    cell.SetCellType(CellType.String);
                    cell.SetCellValue(value);
                    break;
                case "System.DateTime": //日期类型
                    DateTime dateV = new DateTime();
                    if (DateTime.TryParse(value, out dateV))
                    
                        cell.SetCellValue(dateV);
                    
                    else
                    
                        cell.SetCellValue(value);
                    
                    dataFormatStr = "yyyy/mm/dd hh:mm:ss";
                    break;
                case "System.Boolean": //布尔型
                    bool boolV = false;
                    if (bool.TryParse(value, out boolV))
                    
                        cell.SetCellType(CellType.Boolean);
                        cell.SetCellValue(boolV);
                    
                    else
                    
                        cell.SetCellValue(value);
                    
                    break;
                case "System.Int16": //整型
                case "System.Int32":
                case "System.Int64":
                case "System.Byte":
                    int intV = 0;
                    if (int.TryParse(value, out intV))
                    
                        cell.SetCellType(CellType.Numeric);
                        cell.SetCellValue(intV);
                    
                    else
                    
                        cell.SetCellValue(value);
                    
                    dataFormatStr = "0";
                    break;
                case "System.Decimal": //浮点型
                case "System.Double":
                    double doubV = 0;
                    if (double.TryParse(value, out doubV))
                    
                        cell.SetCellType(CellType.Numeric);
                        cell.SetCellValue(doubV);
                    
                    else
                    
                        cell.SetCellValue(value);
                    
                    dataFormatStr = "0.00";
                    break;
                case "System.DBNull": //空值处理
                    cell.SetCellType(CellType.Blank);
                    cell.SetCellValue(string.Empty);
                    break;
                default:
                    cell.SetCellType(CellType.Unknown);
                    cell.SetCellValue(value);
                    break;
            

            if (!string.IsNullOrEmpty(dataFormatStr) && colStyles[cell.ColumnIndex].DataFormat <= 0) //没有设置，则采用默认类型格式
            
                colStyles[cell.ColumnIndex] = GetCellStyleWithDataFormat(cell.Sheet.Workbook, dataFormatStr);
            
            cell.CellStyle = colStyles[cell.ColumnIndex];

            ReSizeColumnWidth(cell.Sheet, cell);
        


        private static ICellStyle GetCellStyleWithDataFormat(IWorkbook workbook, string format)
        
            ICellStyle style = GetCellStyle(workbook);

            var dataFormat = workbook.CreateDataFormat();
            short formatId = -1;
            if (dataFormat is HSSFDataFormat)
            
                formatId = HSSFDataFormat.GetBuiltinFormat(format);
            
            if (formatId != -1)
            
                style.DataFormat = formatId;
            
            else
            
                style.DataFormat = dataFormat.GetFormat(format);
            
            return style;
        


        private static ICellStyle GetCellStyle(IWorkbook workbook, bool isHeaderRow = false)
        
            ICellStyle style = workbook.CreateCellStyle();

            if (isHeaderRow)
            
                style.FillPattern = FillPattern.SolidForeground;
                style.FillForegroundColor = NPOI.HSSF.Util.HSSFColor.Grey25Percent.Index;
                IFont f = workbook.CreateFont();
                f.FontHeightInPoints = 11D;
                f.Boldweight = (short)FontBoldWeight.Bold;
                style.SetFont(f);
            

            style.BorderBottom = NPOI.SS.UserModel.BorderStyle.Thin;
            style.BorderLeft = NPOI.SS.UserModel.BorderStyle.Thin;
            style.BorderRight = NPOI.SS.UserModel.BorderStyle.Thin;
            style.BorderTop = NPOI.SS.UserModel.BorderStyle.Thin;
            return style;
        

        private static void ReSizeColumnWidth(ISheet sheet, ICell cell)
        
            int cellLength = (Encoding.Default.GetBytes(cell.ToString()).Length + 2) * 256;
            const int maxLength = 60 * 256; //255 * 256;
            if (cellLength > maxLength) //当单元格内容超过30个中文字符（英语60个字符）宽度，则强制换行
            
                cellLength = maxLength;
                cell.CellStyle.WrapText = true;
            
            int colWidth = sheet.GetColumnWidth(cell.ColumnIndex);
            if (colWidth < cellLength)
            
                sheet.SetColumnWidth(cell.ColumnIndex, cellLength);
            
        

        private static ISheet GetSheet(IWorkbook workbook, string sheetIndexOrName)
        
            int sheetIndex = 0;
            ISheet sheet = null;

            if (int.TryParse(sheetIndexOrName, out sheetIndex))
            
                sheet = workbook.GetSheetAt(sheetIndex);
            
            else
            
                sheet = workbook.GetSheet(sheetIndexOrName);
            
            return sheet;
        

        /// <summary>
        /// 从工作表中解析生成DataTable
        /// </summary>
        /// <param name="workbook"></param>
        /// <param name="sheetIndexOrName"></param>
        /// <param name="headerRowIndex"></param>
        /// <param name="startColIndex"></param>
        /// <param name="colCount"></param>
        /// <returns></returns>
        public static DataTable ResolveDataTable(this IWorkbook workbook, string sheetIndexOrName, int headerRowIndex, short startColIndex = 0, short colCount = 0)
        
            DataTable table = new DataTable();

            ISheet sheet = GetSheet(workbook, sheetIndexOrName);

            IRow headerRow = sheet.GetRow(headerRowIndex);
            int cellFirstNum = (startColIndex > headerRow.FirstCellNum ? startColIndex : headerRow.FirstCellNum);
            int cellCount = (colCount > 0 && colCount < headerRow.LastCellNum ? colCount : headerRow.LastCellNum);

            for (int i = cellFirstNum; i < cellCount; i++)
            
                if (headerRow.GetCell(i) == null || headerRow.GetCell(i).StringCellValue.Trim() == "")
                
                    // 如果遇到第一个空列，则不再继续向后读取
                    cellCount = i;
                    break;
                
                DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);
                table.Columns.Add(column);
            

            for (int i = (headerRowIndex + 1); i <= sheet.LastRowNum; i++)
            
                IRow row = sheet.GetRow(i);
                if (row != null)
                
                    List<string> cellValues = new List<string>();
                    for (int j = cellFirstNum; j < cellCount; j++)
                    
                        if (row.GetCell(j) != null)
                        
                            cellValues.Add(row.GetCell(j).ToNotNullString());
                        
                        else
                        
                            cellValues.Add(string.Empty);
                        
                    

                    table.Rows.Add(cellValues.ToArray());
                
            

            return table;
        

        /// <summary>
        /// 从工作表中解析生成指定的结果对象列表
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="workbook"></param>
        /// <param name="sheetIndexOrName"></param>
        /// <param name="headerRowIndex"></param>
        /// <param name="buildResultItemFunc"></param>
        /// <param name="startColIndex"></param>
        /// <param name="colCount"></param>
        /// <returns></returns>
        public static List<T> ResolveAs<T>(this IWorkbook workbook, string sheetIndexOrName, int headerRowIndex, Func<List<string>, T> buildResultItemFunc,
            short startColIndex = 0, short colCount = 0)
        
            ISheet sheet = GetSheet(workbook, sheetIndexOrName);

            IRow headerRow = sheet.GetRow(headerRowIndex);
            int cellFirstNum = (startColIndex > headerRow.FirstCellNum ? startColIndex : headerRow.FirstCellNum);
            int cellCount = (colCount > 0 && colCount < headerRow.LastCellNum ? colCount : headerRow.LastCellNum);

            List<T> resultList = new List<T>();
            for (int i = (headerRowIndex + 1); i <= sheet.LastRowNum; i++)
            
                IRow row = sheet.GetRow(i);
                if (row != null)
                
                    List<string> cellValues = new List<string>();
                    for (int j = cellFirstNum; j < cellCount; j++)
                    
                        if (row.GetCell(j) != null)
                        
                            cellValues.Add(row.GetCell(j).ToNotNullString());
                        
                        else
                        
                            cellValues.Add(string.Empty);
                        
                    

                    resultList.Add(buildResultItemFunc(cellValues));
                
            

            return resultList;
        

        public static MemoryStream ToExcelStream(this IWorkbook book)
        
            if (book.NumberOfSheets <= 0)
            
                throw new Exception("无有效的sheet数据");
            

            MemoryStream stream = new MemoryStream();

            stream.Seek(0, SeekOrigin.Begin);
            book.Write(stream);

            return stream;
        

        public static byte[] ToExcelBytes(this IWorkbook book)
        
            using (MemoryStream stream = ToExcelStream(book))
            
                return stream.ToArray();
            
        

        public static JObject HttpUpload(this IWorkbook book, string uploadUrl, IDictionary<string, object> fieldData = null, string exportFileName = null)
        
            using (HttpClient client = new HttpClient())
            
                MultipartFormDataContent formData = new MultipartFormDataContent();
                ByteArrayContent fileContent = new ByteArrayContent(ToExcelBytes(book));
                //StreamContent fileContent = new StreamContent(ToExcelStream(book)); 二者都可以
                fileContent.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
                fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data");

                if (string.IsNullOrWhiteSpace(exportFileName))
                
                    exportFileName = Guid.NewGuid().ToString("N") + ((book is XSSFWorkbook) ? ".xlsx" : ".xls");
                

                fileContent.Headers.ContentDisposition.FileName = exportFileName;
                fileContent.Headers.ContentDisposition.Name = "file";
                formData.Add(fileContent);

                Func<string, StringContent> getStringContent = (str) => new StringContent(str, Encoding.UTF8);

                if (fieldData != null)
                
                    foreach (var header in fieldData)
                    
                        formData.Add(getStringContent(header.Value.ToNotNullString()), header.Key);
                    
                


                HttpResponseMessage res = client.PostAsync(uploadUrl, formData).Result;
                string resContent = res.Content.ReadAsStringAsync().Result;
                return JObject.Parse(resContent);
            
        

        public static string SaveToFile(this IWorkbook book, string filePath)
        
            if (File.Exists(filePath))
            
                File.SetAttributes(filePath, FileAttributes.Normal);
                File.Delete(filePath);
            

            using (FileStream fs = new FileStream(filePath, FileMode.OpenOrCreate, FileAccess.ReadWrite))
            
                book.Write(fs);
            

            return filePath;
        


    

 

　如上代码都比较简单没有什么复杂要，故不再细述。还有一个Core类，这个只是一个入口帮助类，如果已有获得IWorkbook的自定义方法，该类可以不用，代码如下：

using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
using System;
using System.Collections.Generic;
using System.Text;

namespace ExcelEasyUtil

    /// <summary>
    /// NPOI 相关核心入口方法帮助类
    /// author:zuowenjun
    /// 2019-5-21
    /// </summary>
    public static class Core
    
        /// <summary>
        /// 创建一个基本XLSX格式的EXCEL工作薄对象
        /// </summary>
        /// <returns></returns>
        public static IWorkbook CreateXlsxWorkBook()
        
            return new XSSFWorkbook();
        

        /// <summary>
        /// 创建一个基本XLS格式的EXCEL工作薄对象
        /// </summary>
        /// <returns></returns>
        public static IWorkbook CreateXlsWorkBook()
        
            return new HSSFWorkbook();
        

        /// <summary>
        /// 打开指定文件的EXCEL工作薄对象
        /// </summary>
        /// <param name="filePath">Excel文件路径</param>
        /// <returns></returns>
        public static IWorkbook OpenWorkbook(string filePath)
        
            bool isCompatible = filePath.EndsWith(".xls", StringComparison.OrdinalIgnoreCase);
            var fileStream = System.IO.File.OpenRead(filePath);
            if (isCompatible)
            
                return new HSSFWorkbook(fileStream);
            
            else
            
                return new XSSFWorkbook(fileStream);
            
        

    

　虽然代码简单，但方法命名稍有些讲究，易阅读与理解，CreateXlsxWorkBook就是表现创建一个新的基于xlsx格式的工作薄对象，而CreateXlsWorkBook就是表现创建一个新的基于xls格式的工作薄对象，我并没合成一个方法，然后使用一个bool参数或enum参数来区分，我觉得在这个追求极简、高效的开发理念中，方法名要易于理解与快速上手，不应产生歧义，也无需太多的参数。OpenWorkbook就是打开一个已有的EXCEL文件工作薄对象。

 代码虽简单，但我通过合理的封装入参，委托参数等，实现了简单但又不失灵活的EXCEL操作方式，没有一味追求极简，把所有的复杂操作全部封装，从而导致本来简单的事情搞得复杂化，比如：将一个List<T>导出到EXCEL中，常见的实现方式肯定就是通过反射获得属性信息，再利用属性信息获得值，这是做虽入参简单，但性能不好，而本文的这个类库将取值或赋值的方式通过Func委托交由给具体使用的地方，从而避免了反射带来的性能损失，好了，如下展示几个使用示例，帮助大家理解和使用。

第一种填充sheet方式：(重点在表格头的映射设置，通过Lamba属性表达式与要生成的EXCEL表头进行关联映射)

var book= ExcelEasyUtil.Core.CreateXlsxWorkBook()
                .FillSheet("人员列表1", peoples,//填充第一个表格
                //new Dictionary<string, Expression<Func<People, dynamic>>> //设置表格头，原始类型
               new PropertyColumnMapping<People> //设置表格头，专用简化类型
               
                "姓名",p=>p.Name ,"年龄",p=>p.Age ,"生日",p=>p.Birthday ,"住址",p=>p.Address ,"学历",p=>p.Education ,
                 "有工作否",p=>p.hasWork ,"备注",p=>p.Remark 
               ,
               new Dictionary<string, string> //为指定的列设置单元格格式
               
                 "年龄","0岁","生日","yyyy年mm月dd日"
               );

 第二种填充sheet方式：(重点在表格头类型设置【:XXX表示生成的EXCEL该列为某种格式的单元格，如：生日:DT表示是生日这列导出是日期类型格式】，第二个参数返回List<object>这个是可以很好的控制导出时需要的填充数据，可以自由控制数据，比如示例代码中额外增加了一列判断的数据列内容，第三个参数是为指定的列设置单元格的具体应用格式)

var book= ExcelEasyUtil.Core.CreateXlsxWorkBook() 
.FillSheet("人员列表2", peoples,  //填充第二个表格
               new List<string>
               
                   "姓名","年龄:NUM","生日:DT","住址","学历","有工作否:BL","备注","额外填充列"
               , (p) =>
               
                   return new List<object> 
                       p.Name,p.Age,p.Birthday,p.Address,p.Education,p.hasWork?"有":"无",p.Remark,(p.Age<=30 && p.hasWork)?"年轻有为":"要么老了要么没工作，生活堪忧"
                   ;
               , new Dictionary<string, string>
               
                    "生日","yyyy-mm-dd"
               );

　第三种填充sheet方式：（重点仍然是在表头映射，由于这里的数据源是DataTable，故只是设置DataTable的列与EXCEL要导出的列名映射即可，无需指定列类型，第二个参数是为指定的列设置单元格的具体应用格式）

var book= ExcelEasyUtil.Core.CreateXlsxWorkBook()  
 .FillSheet("人员列表3", peoplesTable, //填充第三个表格
               new Dictionary<string, string> 
                   "Name","姓名" ,"Birthday","生日" ,"Address","住址" ,"Education","学历" , "hasWork","有工作否" ,"Remark","备注" 
               
               , new Dictionary<string, string>
               
                    "生日","yyyy-mm-dd"
               );

　由于实现了FillSheet方法后仍返回IWorkBook实例本身，即可采用链式的方式来快速完成多个sheet导出的，合并代码如下：

 string savedPath = ExcelEasyUtil.Core.CreateXlsxWorkBook()
                .FillSheet("人员列表1", peoples,//填充第一个表格
               //new Dictionary<string, Expression<Func<People, dynamic>>> //设置表格头，原始类型
               new PropertyColumnMapping<People> //设置表格头，专用简化类型
               
                "姓名",p=>p.Name ,"年龄",p=>p.Age ,"生日",p=>p.Birthday ,"住址",p=>p.Address ,"学历",p=>p.Education ,
                 "有工作否",p=>p.hasWork ,"备注",p=>p.Remark 
               ,
               new Dictionary<string, string> //为指定的列设置单元格格式
               
                 "年龄","0岁","生日","yyyy年mm月dd日"
               )
               .FillSheet("人员列表2", peoples,  //填充第二个表格
               new List<string>
               
                   "姓名","年龄:NUM","生日:DT","住址","学历","有工作否:BL","备注","额外填充列"
               , (p) =>
               
                   return new List<object> 
                       p.Name,p.Age,p.Birthday,p.Address,p.Education,p.hasWork?"有":"无",p.Remark,(p.Age<=30 && p.hasWork)?"年轻有为":"要么老了要么没工作，生活堪忧"
                   ;
               , new Dictionary<string, string>
               
                    "生日","yyyy-mm-dd"
               )
               .FillSheet("人员列表3", peoplesTable, //填充第三个表格
               new Dictionary<string, string> 
                   "Name","姓名" ,"Birthday","生日" ,"Address","住址" ,"Education","学历" , "hasWork","有工作否" ,"Remark","备注" 
               
               , new Dictionary<string, string>
               
                    "生日","yyyy-mm-dd"
               )
               .SaveToFile(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "testdata123.xlsx"));

            Console.WriteLine("导出EXCEL文件路径：" + savedPath);

　感觉如何，EXCEL导出既能设置列头，列格式，还能控制填充的数据值，认为是否够方便呢，我个人觉得还是可以满足日常大部份的使用EXCEL的需求。

　说了导出EXCEL方法再来贴出导入EXCEL数据（这里称为解析EXCEL数据）的示例用法：

 var xlsTable = ExcelEasyUtil.Core.OpenWorkbook(savedPath).ResolveDataTable("人员列表1", 0);
            foreach (DataRow row in xlsTable.Rows)
            
                string rowStr = string.Join("\\t", row.ItemArray);
                Console.WriteLine(rowStr);
            

            var xlsPeoples = ExcelEasyUtil.Core.OpenWorkbook(savedPath).ResolveAs<People>("人员列表2", 0, list =>
            
                return new People
                
                    Name = list[0],
                    Birthday = ConvertToDate(list[2]),//日期处理相对较麻烦
                    Address = list[3]
                ;
            , 0, 4);

            Console.WriteLine("-".PadRight(30,‘-‘));
            foreach (var p in xlsPeoples)
            
                string rowStr = string.Join("\\t", p.Name, p.Age, p.Birthday, p.Address);
                Console.WriteLine(rowStr);
            

这里仅实现了解析到DataTable或解析到所需的对象集合，一般也能满足常见的导入数据的要求。

当然还有：HttpUpload方法，这个主要是把生成的内存EXCEL文件直接上传至指定的文件服务器的，如果是在ASP.NET，ASP.NET CORE服务端需要下载，那么则可以采用先使用：book.ToExcelBytes()，然后构造文件字节流Result即可，比如：MVC中的File，可以参照我本文一开始列举的第二中方法中的导出，在此就不再贴示例了。

好了，以上就是本文的全部内容，可能大神们认为这太简单了，但我认为简单高效的实用类库还是需要的，因为ExcelEasyUtil本身就是为简单、轻量、实用而封装的，故不会有太多复杂的东西，如果需要复杂的EXCEL操作就使用我上面说的第四种方案：ExcelUtility。

若有不足之处或好的建议，欢迎评论，谢谢！

本文ExcelEasyUtil源代码地址：https://github.com/zuowj/ExcelEasyUtil   （文中的所有示例代码在github均有）

为了方便开发者使用，还封装成了NuGet包：　

Packge Manager：Install-Package ExcelEasyUtil -Version 1.0.0

.NET CLI：dotnet add package ExcelEasyUtil --version 1.0.0 OR <PackageReference Include="ExcelEasyUtil" Version="1.0.0" />