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    asp.net(C#)之NPOI"操作Excel

    作者:admin来源:网络浏览:时间:2020-09-30 00:07:50我要评论
    导读: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 Syst...
    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">
            /// <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 name="file">
            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">
            /// <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">
            /// <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 name="file">
            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">
            /// <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;
        }
    }</int></int></int></int>

    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();
        }
    }
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