C#解压文件，Excel操作

        /// <summary>
        /// 获取目录下文件路径
        /// </summary>
        /// <param name="path"></param>
        /// <param name="type">例如:"zip","xls"</param>
        /// <returns></returns>
        List<string> GetFilesPath(string path,string type)
        {
            List<string> filesPath = new List<string>();
            FileInfo[] files = GetFileInfo(path);
            foreach (FileInfo item in files)
            {
                if (item.FullName.Contains(type))
                {
                    filesPath.Add(item.FullName);
                }
            }
            return filesPath;
        }
        /// <summary>
        /// 获取路径下的所有文件
        /// </summary>
        /// <param name="path">文件夹路径</param>
        /// <returns>所有文件</returns>
        FileInfo[] GetFileInfo(string path)
        {
            DirectoryInfo root = new DirectoryInfo(path);
            FileInfo[] files = root.GetFiles();
            return files;
        }        

读取.xls文件到DataSet

        /// <summary>
        /// 读取Excel表
        /// </summary>
        /// <param name="filePath">路径</param>
        /// <param name="table">表名</param>
        /// <returns>DataSet</returns>
        public static DataSet LoadDataFromExcel(string filePath, string table)
        {
            try
            {
                string strConn;
                strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filePath + ";Extended Properties='Excel 8.0;HDR=False;IMEX=1'";
                OleDbConnection OleConn = new OleDbConnection(strConn);
                OleConn.Open();
                String sql = "SELECT * FROM  [" + table + "$]";//可是更改Sheet名称，比如sheet2，等等 

                OleDbDataAdapter OleDaExcel = new OleDbDataAdapter(sql, OleConn);
                DataSet OleDsExcle = new DataSet();
                OleDaExcel.Fill(OleDsExcle, table);
                OleConn.Close();
                return OleDsExcle;
            }
            catch (Exception err)
            {
                //MessageBox.Show("数据绑定Excel失败!失败原因：" + err.Message, "提示信息",
                //MessageBoxButtons.OK, MessageBoxIcon.Information);
                return null;
            }
        }        

导出DataTable到.xls格式，如果是.xlsx将代码中HSS改为XSS

首先引入NPOI

/// <summary>
        /// DataTable导出到Excel文件 .xls格式
        /// </summary>
        /// <param name="dtSource">源DataSet</param>
        /// <param name="strFileName">保存位置</param>
        public static void DataTableToExcel(DataTable dt, string strFileName)
        {
            using (MemoryStream ms = DataSetToExcel(dt))
            {
                using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
                {
                    byte[] data = ms.ToArray();
                    fs.Write(data, 0, data.Length);
                    fs.Flush();
                }
            }
        }

        /// <summary>
        /// DataTable导出到Excel的MemoryStream
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
        public static MemoryStream DataSetToExcel(DataTable dt)
        {
            HSSFWorkbook workbook = new HSSFWorkbook();

            //   HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet();
            HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet(dt.TableName.ToString());

            #region 右击文件 属性信息
            {
                DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
                dsi.Company = "NPOI";

                // workbook.DocumentSummaryInformation = dsi;

                SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
                //si.Author = "文件作者信息"; //填加xls文件作者信息
                //si.ApplicationName = "创建程序信息"; //填加xls文件创建程序信息
                //si.LastAuthor = "最后保存者信息"; //填加xls文件最后保存者信息
                //si.Comments = "作者信息"; //填加xls文件作者信息
                //si.Title = "标题信息"; //填加xls文件标题信息
                //si.Subject = "主题信息";//填加文件主题信息
                si.CreateDateTime = System.DateTime.Now;
                // workbook.SummaryInformation = si;
            }
            #endregion

            HSSFCellStyle dateStyle = (HSSFCellStyle)workbook.CreateCellStyle();
            HSSFDataFormat format = (HSSFDataFormat)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 dt.Rows)
            {
                #region 新建表，填充表头，填充列头，样式
                if (rowIndex == 0)
                {
                    //if (rowIndex != 0)
                    //{
                    //    sheet = (XSSFSheet)workbook.CreateSheet();
                    //}
                    #region 表头及样式
                    //{
                    //XSSFRow headerRow = (XSSFRow)sheet.CreateRow(0);
                    //headerRow.HeightInPoints = 25;
                    //headerRow.CreateCell(0).SetCellValue(strHeaderText);

                    //HSSFCellStyle headStyle = (HSSFCellStyle)workbook.CreateCellStyle();
                    ////  headStyle.Alignment = CellHorizontalAlignment.CENTER;
                    //HSSFFont font = (HSSFFont)workbook.CreateFont();
                    //font.FontHeightInPoints = 20;
                    //font.Boldweight = 700;
                    //headStyle.SetFont(font);
                    //headerRow.GetCell(0).CellStyle = headStyle;
                    //// sheet.AddMergedRegion(new Region(0, 0, 0, dtSource.Columns.Count - 1));
                    ////headerRow.Dispose();
                    //}
                    #endregion

                    #region 列头及样式
                    //{
                    //    XSSFRow headerRow = (XSSFRow)sheet.CreateRow(0);
                    //    XSSFCellStyle headStyle = (XSSFCellStyle)workbook.CreateCellStyle();
                    //    //headStyle.Alignment = CellHorizontalAlignment.CENTER;
                    //    XSSFFont font = (XSSFFont)workbook.CreateFont();
                    //    font.FontHeightInPoints = 10;
                    //    font.Boldweight = 700;
                    //    headStyle.SetFont(font);
                    //    foreach (DataColumn column in ds.Tables[k].Columns)
                    //    {
                    //        headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
                    //        headerRow.GetCell(column.Ordinal).CellStyle = headStyle;

                    //        //设置列宽
                    //        //   sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256);
                    //    }
                    //    // headerRow.Dispose();
                    //}
                    #endregion

                    rowIndex = 1;
                }
                #endregion

                #region 填充内容
                HSSFRow dataRow = (HSSFRow)sheet.CreateRow(rowIndex);
                foreach (DataColumn column in dt.Columns)
                {
                    HSSFCell newCell = (HSSFCell)dataRow.CreateCell(column.Ordinal);

                    string drValue = row[column].ToString();

                    switch (column.DataType.ToString())
                    {
                        case "System.String"://字符串类型
                            newCell.SetCellValue(drValue);
                            break;
                        case "System.DateTime"://日期类型
                            System.DateTime dateV;
                            System.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("");
                            break;
                    }

                }
                #endregion
                rowIndex++;
            }

            using (MemoryStream ms = new MemoryStream())
            {
                workbook.Write(ms);
                ms.Flush();
                return ms;
            }
        }

导出DataTable到.csv格式

public static void Export2CSV(DataTable data, string filename, bool exportHeader = true)
        {
            if (File.Exists(filename))
                File.Delete(filename);

            var buffer = new StringBuilder();
            if (exportHeader)
            {
                for (var i = 0; i < data.Columns.Count; i++)
                {
                    buffer.AppendFormat("\"{0}\"", data.Columns[i].ColumnName);
                    if (i < data.Columns.Count - 1)
                        buffer.Append(",");
                }
                buffer.AppendLine();
            }

            for (var i = 0; i < data.Rows.Count; i++)
            {
                for (var j = 0; j < data.Columns.Count; j++)
                {
                    buffer.AppendFormat("\"{0}\"", data.Rows[i][j].ToString());
                    if (j < data.Columns.Count - 1)
                        buffer.Append(",");
                }
                buffer.AppendLine();
            }

            File.WriteAllText(filename, buffer.ToString(), Encoding.Default);
        }

Zip解压 引入插件：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.Checksums;

namespace Jerry.API.C
{
    /// <summary>   
    /// 适用与ZIP压缩   
    /// </summary>   
    public class ZipHelper
    {
        #region 压缩

        /// <summary>   
        /// 递归压缩文件夹的内部方法   
        /// </summary>   
        /// <param name="folderToZip">要压缩的文件夹路径</param>   
        /// <param name="zipStream">压缩输出流</param>   
        /// <param name="parentFolderName">此文件夹的上级文件夹</param>   
        /// <returns></returns>   
        private static bool ZipDirectory(string folderToZip, ZipOutputStream zipStream, string parentFolderName)
        {
            bool result = true;
            string[] folders, files;
            ZipEntry ent = null;
            FileStream fs = null;
            Crc32 crc = new Crc32();

            try
            {
                ent = new ZipEntry(Path.Combine(parentFolderName, Path.GetFileName(folderToZip) + "/"));
                zipStream.PutNextEntry(ent);
                zipStream.Flush();

                files = Directory.GetFiles(folderToZip);
                foreach (string file in files)
                {
                    fs = File.OpenRead(file);

                    byte[] buffer = new byte[fs.Length];
                    fs.Read(buffer, 0, buffer.Length);
                    ent = new ZipEntry(Path.Combine(parentFolderName, Path.GetFileName(folderToZip) + "/" + Path.GetFileName(file)));
                    ent.DateTime = DateTime.Now;
                    ent.Size = fs.Length;

                    fs.Close();

                    crc.Reset();
                    crc.Update(buffer);

                    ent.Crc = crc.Value;
                    zipStream.PutNextEntry(ent);
                    zipStream.Write(buffer, 0, buffer.Length);
                }

            }
            catch
            {
                result = false;
            }
            finally
            {
                if (fs != null)
                {
                    fs.Close();
                    fs.Dispose();
                }
                if (ent != null)
                {
                    ent = null;
                }
                GC.Collect();
                GC.Collect(1);
            }

            folders = Directory.GetDirectories(folderToZip);
            foreach (string folder in folders)
                if (!ZipDirectory(folder, zipStream, folderToZip))
                    return false;

            return result;
        }

        /// <summary>   
        /// 压缩文件夹    
        /// </summary>   
        /// <param name="folderToZip">要压缩的文件夹路径</param>   
        /// <param name="zipedFile">压缩文件完整路径</param>   
        /// <param name="password">密码</param>   
        /// <returns>是否压缩成功</returns>   
        public static bool ZipDirectory(string folderToZip, string zipedFile, string password)
        {
            bool result = false;
            if (!Directory.Exists(folderToZip))
                return result;

            ZipOutputStream zipStream = new ZipOutputStream(File.Create(zipedFile));
            zipStream.SetLevel(6);
            if (!string.IsNullOrEmpty(password)) zipStream.Password = password;

            result = ZipDirectory(folderToZip, zipStream, "");

            zipStream.Finish();
            zipStream.Close();

            return result;
        }

        /// <summary>   
        /// 压缩文件夹   
        /// </summary>   
        /// <param name="folderToZip">要压缩的文件夹路径</param>   
        /// <param name="zipedFile">压缩文件完整路径</param>   
        /// <returns>是否压缩成功</returns>   
        public static bool ZipDirectory(string folderToZip, string zipedFile)
        {
            bool result = ZipDirectory(folderToZip, zipedFile, null);
            return result;
        }

        /// <summary>   
        /// 压缩文件   
        /// </summary>   
        /// <param name="fileToZip">要压缩的文件全名</param>   
        /// <param name="zipedFile">压缩后的文件名</param>   
        /// <param name="password">密码</param>   
        /// <returns>压缩结果</returns>   
        public static bool ZipFile(string fileToZip, string zipedFile, string password)
        {
            bool result = true;
            ZipOutputStream zipStream = null;
            FileStream fs = null;
            ZipEntry ent = null;

            if (!File.Exists(fileToZip))
                return false;

            try
            {
                fs = File.OpenRead(fileToZip);
                byte[] buffer = new byte[fs.Length];
                fs.Read(buffer, 0, buffer.Length);
                fs.Close();

                fs = File.Create(zipedFile);
                zipStream = new ZipOutputStream(fs);
                if (!string.IsNullOrEmpty(password)) zipStream.Password = password;
                ent = new ZipEntry(Path.GetFileName(fileToZip));
                zipStream.PutNextEntry(ent);
                zipStream.SetLevel(6);

                zipStream.Write(buffer, 0, buffer.Length);

            }
            catch
            {
                result = false;
            }
            finally
            {
                if (zipStream != null)
                {
                    zipStream.Finish();
                    zipStream.Close();
                }
                if (ent != null)
                {
                    ent = null;
                }
                if (fs != null)
                {
                    fs.Close();
                    fs.Dispose();
                }
            }
            GC.Collect();
            GC.Collect(1);

            return result;
        }

        /// <summary>   
        /// 压缩文件   
        /// </summary>   
        /// <param name="fileToZip">要压缩的文件全名</param>   
        /// <param name="zipedFile">压缩后的文件名</param>   
        /// <returns>压缩结果</returns>   
        public static bool ZipFile(string fileToZip, string zipedFile)
        {
            bool result = ZipFile(fileToZip, zipedFile, null);
            return result;
        }

        /// <summary>   
        /// 压缩文件或文件夹   
        /// </summary>   
        /// <param name="fileToZip">要压缩的路径</param>   
        /// <param name="zipedFile">压缩后的文件名</param>   
        /// <param name="password">密码</param>   
        /// <returns>压缩结果</returns>   
        public static bool Zip(string fileToZip, string zipedFile, string password)
        {
            bool result = false;
            if (Directory.Exists(fileToZip))
                result = ZipDirectory(fileToZip, zipedFile, password);
            else if (File.Exists(fileToZip))
                result = ZipFile(fileToZip, zipedFile, password);

            return result;
        }

        /// <summary>   
        /// 压缩文件或文件夹   
        /// </summary>   
        /// <param name="fileToZip">要压缩的路径</param>   
        /// <param name="zipedFile">压缩后的文件名</param>   
        /// <returns>压缩结果</returns>   
        public static bool Zip(string fileToZip, string zipedFile)
        {
            bool result = Zip(fileToZip, zipedFile, null);
            return result;

        }

        #endregion

        #region 解压

        /// <summary>   
        /// 解压功能(解压压缩文件到指定目录)   
        /// </summary>   
        /// <param name="fileToUnZip">待解压的文件</param>   
        /// <param name="zipedFolder">指定解压目标目录</param>   
        /// <param name="password">密码</param>   
        /// <returns>解压结果</returns>   
        public static bool UnZip(string fileToUnZip, string zipedFolder, string password)
        {
            bool result = true;
            FileStream fs = null;
            ZipInputStream zipStream = null;
            ZipEntry ent = null;
            string fileName;

            if (!File.Exists(fileToUnZip))
                return false;

            if (!Directory.Exists(zipedFolder))
                Directory.CreateDirectory(zipedFolder);

            try
            {
                zipStream = new ZipInputStream(File.OpenRead(fileToUnZip));
                if (!string.IsNullOrEmpty(password)) zipStream.Password = password;
                while ((ent = zipStream.GetNextEntry()) != null)
                {
                    if (!string.IsNullOrEmpty(ent.Name))
                    {
                        fileName = Path.Combine(zipedFolder, ent.Name);
                        fileName = fileName.Replace('/', '\\');//change by Mr.HopeGi   

                        if (fileName.EndsWith("\\"))
                        {
                            Directory.CreateDirectory(fileName);
                            continue;
                        }

                        fs = File.Create(fileName);
                        int size = 2048;
                        byte[] data = new byte[size];
                        while (true)
                        {
                            size = zipStream.Read(data, 0, data.Length);
                            if (size > 0)
                                fs.Write(data, 0, data.Length);
                            else
                                break;
                        }
                    }
                }
            }
            catch
            {
                result = false;
            }
            finally
            {
                if (fs != null)
                {
                    fs.Close();
                    fs.Dispose();
                }
                if (zipStream != null)
                {
                    zipStream.Close();
                    zipStream.Dispose();
                }
                if (ent != null)
                {
                    ent = null;
                }
                GC.Collect();
                GC.Collect(1);
            }
            return result;
        }

        /// <summary>   
        /// 解压功能(解压压缩文件到指定目录)   
        /// </summary>   
        /// <param name="fileToUnZip">待解压的文件</param>   
        /// <param name="zipedFolder">指定解压目标目录</param>   
        /// <returns>解压结果</returns>   
        public static bool UnZip(string fileToUnZip, string zipedFolder)
        {
            bool result = UnZip(fileToUnZip, zipedFolder, null);
            return result;
        }

        #endregion
    }  
}