asp.net(C#)之NPOI"操作Excel

我会带着你远行 2022-06-13 01:21 550阅读 0赞

1.首先到网上下载"NPOI.DLL"，引用。

2.新建一个操作类“ExcelHelper.cs”：

using System.Collections.Generic;  
    using System.Data;  
    using System.IO;  
    using System.Linq;  
    using NPOI.HSSF.UserModel;  
    using NPOI.SS.UserModel;  
    using NPOI.XSSF.UserModel;  
      
    public class ExcelHelper  
    {  
        public class x2003  
        {  
            #region Excel2003  
            /// <summary>  
            /// 将Excel文件中的数据读出到DataTable中(xls)  
            /// </summary>  
            /// <param name="file"></param>  
            /// <returns></returns>  
            public static DataTable ExcelToTableForXLS(string file)  
            {  
                DataTable dt = new DataTable();  
                using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))  
                {  
                    HSSFWorkbook hssfworkbook = new HSSFWorkbook(fs);  
                    ISheet sheet = hssfworkbook.GetSheetAt(0);  
      
                    //表头  
                    IRow header = sheet.GetRow(sheet.FirstRowNum);  
                    List<int> columns = new List<int>();  
                    for (int i = 0; i < header.LastCellNum; i++)  
                    {  
                        object obj = GetValueTypeForXLS(header.GetCell(i) as HSSFCell);  
                        if (obj == null || obj.ToString() == string.Empty)  
                        {  
                            dt.Columns.Add(new DataColumn("Columns" + i.ToString()));  
                            //continue;  
                        }  
                        else  
                            dt.Columns.Add(new DataColumn(obj.ToString()));  
                        columns.Add(i);  
                    }  
                    //数据  
                    for (int i = sheet.FirstRowNum + 1; i <= sheet.LastRowNum; i++)  
                    {  
                        DataRow dr = dt.NewRow();  
                        bool hasValue = false;  
                        foreach (int j in columns)  
                        {  
                            dr[j] = GetValueTypeForXLS(sheet.GetRow(i).GetCell(j) as HSSFCell);  
                            if (dr[j] != null && dr[j].ToString() != string.Empty)  
                            {  
                                hasValue = true;  
                            }  
                        }  
                        if (hasValue)  
                        {  
                            dt.Rows.Add(dr);  
                        }  
                    }  
                }  
                return dt;  
            }  
      
            /// <summary>  
            /// 将DataTable数据导出到Excel文件中(xls)  
            /// </summary>  
            /// <param name="dt"></param>  
            /// <param name="file"></param>  
            public static void TableToExcelForXLS(DataTable dt, string file)  
            {  
                HSSFWorkbook hssfworkbook = new HSSFWorkbook();  
                ISheet sheet = hssfworkbook.CreateSheet("Test");  
      
                //表头  
                IRow row = sheet.CreateRow(0);  
                for (int i = 0; i < dt.Columns.Count; i++)  
                {  
                    ICell cell = row.CreateCell(i);  
                    cell.SetCellValue(dt.Columns[i].ColumnName);  
                }  
      
                //数据  
                for (int i = 0; i < dt.Rows.Count; i++)  
                {  
                    IRow row1 = sheet.CreateRow(i + 1);  
                    for (int j = 0; j < dt.Columns.Count; j++)  
                    {  
                        ICell cell = row1.CreateCell(j);  
                        cell.SetCellValue(dt.Rows[i][j].ToString());  
                    }  
                }  
      
                //转为字节数组  
                MemoryStream stream = new MemoryStream();  
                hssfworkbook.Write(stream);  
                var buf = stream.ToArray();  
      
                //保存为Excel文件  
                using (FileStream fs = new FileStream(file, FileMode.Create, FileAccess.Write))  
                {  
                    fs.Write(buf, 0, buf.Length);  
                    fs.Flush();  
                }  
            }  
      
            /// <summary>  
            /// 获取单元格类型(xls)  
            /// </summary>  
            /// <param name="cell"></param>  
            /// <returns></returns>  
            private static object GetValueTypeForXLS(HSSFCell cell)  
            {  
                if (cell == null)  
                    return null;  
                switch (cell.CellType)  
                {  
                    case CellType.Blank: //BLANK:  
                        return null;  
                    case CellType.Boolean: //BOOLEAN:  
                        return cell.BooleanCellValue;  
                    case CellType.Numeric: //NUMERIC:  
                        return cell.NumericCellValue;  
                    case CellType.String: //STRING:  
                        return cell.StringCellValue;  
                    case CellType.Error: //ERROR:  
                        return cell.ErrorCellValue;  
                    case CellType.Formula: //FORMULA:  
                    default:  
                        return "=" + cell.CellFormula;  
                }  
            }  
            #endregion  
        }  
      
        public class x2007  
        {  
            #region Excel2007  
            /// <summary>  
            /// 将Excel文件中的数据读出到DataTable中(xlsx)  
            /// </summary>  
            /// <param name="file"></param>  
            /// <returns></returns>  
            public static DataTable ExcelToTableForXLSX(string file)  
            {  
                DataTable dt = new DataTable();  
                using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))  
                {  
                    XSSFWorkbook xssfworkbook = new XSSFWorkbook(fs);  
                    ISheet sheet = xssfworkbook.GetSheetAt(0);  
      
                    //表头  
                    IRow header = sheet.GetRow(sheet.FirstRowNum);  
                    List<int> columns = new List<int>();  
                    for (int i = 0; i < header.LastCellNum; i++)  
                    {  
                        object obj = GetValueTypeForXLSX(header.GetCell(i) as XSSFCell);  
                        if (obj == null || obj.ToString() == string.Empty)  
                        {  
                            dt.Columns.Add(new DataColumn("Columns" + i.ToString()));  
                            //continue;  
                        }  
                        else  
                            dt.Columns.Add(new DataColumn(obj.ToString()));  
                        columns.Add(i);  
                    }  
                    //数据  
                    for (int i = sheet.FirstRowNum + 1; i <= sheet.LastRowNum; i++)  
                    {  
                        DataRow dr = dt.NewRow();  
                        bool hasValue = false;  
                        foreach (int j in columns)  
                        {  
                            dr[j] = GetValueTypeForXLSX(sheet.GetRow(i).GetCell(j) as XSSFCell);  
                            if (dr[j] != null && dr[j].ToString() != string.Empty)  
                            {  
                                hasValue = true;  
                            }  
                        }  
                        if (hasValue)  
                        {  
                            dt.Rows.Add(dr);  
                        }  
                    }  
                }  
                return dt;  
            }  
      
            /// <summary>  
            /// 将DataTable数据导出到Excel文件中(xlsx)  
            /// </summary>  
            /// <param name="dt"></param>  
            /// <param name="file"></param>  
            public static void TableToExcelForXLSX(DataTable dt, string file)  
            {  
                XSSFWorkbook xssfworkbook = new XSSFWorkbook();  
                ISheet sheet = xssfworkbook.CreateSheet("Test");  
      
                //表头  
                IRow row = sheet.CreateRow(0);  
                for (int i = 0; i < dt.Columns.Count; i++)  
                {  
                    ICell cell = row.CreateCell(i);  
                    cell.SetCellValue(dt.Columns[i].ColumnName);  
                }  
      
                //数据  
                for (int i = 0; i < dt.Rows.Count; i++)  
                {  
                    IRow row1 = sheet.CreateRow(i + 1);  
                    for (int j = 0; j < dt.Columns.Count; j++)  
                    {  
                        ICell cell = row1.CreateCell(j);  
                        cell.SetCellValue(dt.Rows[i][j].ToString());  
                    }  
                }  
      
                //转为字节数组  
                MemoryStream stream = new MemoryStream();  
                xssfworkbook.Write(stream);  
                var buf = stream.ToArray();  
      
                //保存为Excel文件  
                using (FileStream fs = new FileStream(file, FileMode.Create, FileAccess.Write))  
                {  
                    fs.Write(buf, 0, buf.Length);  
                    fs.Flush();  
                }  
            }  
      
            /// <summary>  
            /// 获取单元格类型(xlsx)  
            /// </summary>  
            /// <param name="cell"></param>  
            /// <returns></returns>  
            private static object GetValueTypeForXLSX(XSSFCell cell)  
            {  
                if (cell == null)  
                    return null;  
                switch (cell.CellType)  
                {  
                    case CellType.Blank: //BLANK:  
                        return null;  
                    case CellType.Boolean: //BOOLEAN:  
                        return cell.BooleanCellValue;  
                    case CellType.Numeric: //NUMERIC:  
                        return cell.NumericCellValue;  
                    case CellType.String: //STRING:  
                        return cell.StringCellValue;  
                    case CellType.Error: //ERROR:  
                        return cell.ErrorCellValue;  
                    case CellType.Formula: //FORMULA:  
                    default:  
                        return "=" + cell.CellFormula;  
                }  
            }  
            #endregion  
        }  
      
        public static DataTable GetDataTable(string filepath)  
        {  
            var dt = new DataTable("xls");  
            if (filepath.Last()=='s')  
            {  
                dt = x2003.ExcelToTableForXLS(filepath);  
            }  
            else  
            {  
                dt = x2007.ExcelToTableForXLSX(filepath);  
            }  
            return dt;  
        }  
    }

3.程序后台主要代码：

using System;  
    using System.Collections.Generic;  
    using System.Web;  
    using System.Web.UI;  
    using System.Web.UI.WebControls;  
    using System.Data;  
    using System.Linq;  
    public partial class _Default : System.Web.UI.Page   
    {  
        protected void Page_Load(object sender, EventArgs e)  
        {  
      
        }  
        protected void btn_read_03_click(object o, EventArgs e)  
        {  
            var dt = ExcelHelper.GetDataTable(Server.MapPath("~/xls_tmp/2003.xls"));  
            g1.DataSource = dt;  
            g1.DataBind();  
        }  
        protected void btn_read_07_click(object o, EventArgs e)  
        {  
            var dt = ExcelHelper.GetDataTable(Server.MapPath("~/xls_tmp/2007.xlsx"));  
            g1.DataSource = dt;  
            g1.DataBind();  
        }  
        protected void btn_import_03_click(object o, EventArgs e)  
        {  
            var name = DateTime.Now.ToString("yyyyMMddhhmmss") + new Random(DateTime.Now.Second).Next(10000);  
            var path = Server.MapPath("~/xls_down/" + name + ".xls");  
            var dt = new System.Data.DataTable();  
            var Columns=Enumerable.Range(1, 10).Select(d => new DataColumn("a"+d.ToString(), typeof(string))).ToArray();  
            dt.Columns.AddRange(Columns);  
            for (int i = 0; i < 33333; i++)  
            {  
                var id = Guid.NewGuid().ToString();  
                dt.Rows.Add(id, id, id, id, id, id, id, id, id, id);  
            }  
            ExcelHelper.x2003.TableToExcelForXLS(dt, path);  
            downloadfile(path);  
        }  
        protected void btn_import_07_click(object o, EventArgs e)  
        {  
            var name = DateTime.Now.ToString("yyyyMMddhhmmss") + new Random(DateTime.Now.Second).Next(10000);  
            var path = Server.MapPath("~/xls_down/" + name + ".xlsx");  
            var dt = new System.Data.DataTable();  
            var Columns = Enumerable.Range(1, 10).Select(d => new DataColumn("a" + d.ToString(), typeof(string))).ToArray();  
            dt.Columns.AddRange(Columns);  
            for (int i = 0; i < 33333; i++)  
            {  
                var id = Guid.NewGuid().ToString();  
                dt.Rows.Add(id, id, id, id, id, id, id, id, id, id);  
            }  
            ExcelHelper.x2007.TableToExcelForXLSX(dt, path);  
            downloadfile(path);  
        }  
        void downloadfile(string s_path)  
        {  
            System.IO.FileInfo file = new System.IO.FileInfo(s_path);  
            HttpContext.Current.Response.ContentType = "application/ms-download";  
            HttpContext.Current.Response.Clear();  
            HttpContext.Current.Response.AddHeader("Content-Type", "application/octet-stream");  
            HttpContext.Current.Response.Charset = "utf-8";  
            HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + System.Web.HttpUtility.UrlEncode(file.Name, System.Text.Encoding.UTF8));  
            HttpContext.Current.Response.AddHeader("Content-Length", file.Length.ToString());  
            HttpContext.Current.Response.WriteFile(file.FullName);  
            HttpContext.Current.Response.Flush();  
            HttpContext.Current.Response.Clear();  
            HttpContext.Current.Response.End();  
        }  
    }