C#读取excel文件 博客分类： C# C#excelcsvxlsxNPOI

C#读取excel文件

   最近在项目中应用到读取excel文件的功能，在此总结一下开发经验。

   读取数据分为两种情况，一种是csv格式的文件，另一种是xlsx格式的文件。

首先需要注意的是：csv文件是以英文逗号间隔的文本文件，而xlsx是电子表格，包含文本、数值、公式和格式。

代码示例：

 

读取csv文件

public class StudentEntity {
            public String name;
            public String no;
            public String fileName;
        }
        public String ReadCsvFileToEntityList(string filePath, String fileName, List<StudentEntity> stuList)
        {
            LoadUtil util = new LoadUtil();
            String result = "S";
            int i = 0;
            try
            {
                String fileAllName = filePath + @"\" + fileName;
                using (StreamReader sr = new StreamReader(fileAllName, Encoding.Default))
                {
                    String line;
                    // 构造解析器
                    SeperatorBasedParser parser = new SeperatorBasedParser(seperator: SeperatorType.COMMA);
                    // 按行拆解数据文件
                    while (!String.IsNullOrEmpty(line = sr.ReadLine()))
                    {
                        //去掉文件头
                        if (line.Contains("学号"))
                        {
                            continue;
                        }
                        var entity = parser.ParseStringToEntity<StudentEntity>(line);
                        String[] lineList = line.Split(',');//根据英文逗号分隔
                        entity.fileName = fileName;//文件名
                        entity.no = lineList[0];//学号
                        entity.name = lineList[1];//姓名
                        stuList.Add(entity);
                        i++;
                    }
                    Console.WriteLine("Total lines: " + i.ToString());
                    FileLogger.log("LoadManager.ParseFileToEntityList Succeed! " + fileAllName);
                }
            }
            catch (Exception e)
            {
                // Let the user know what went wrong.
                Console.WriteLine("The file " + fileName + " could not be read: " + ", error line: " + i.ToString());
                Console.WriteLine(e.Message);
                FileLogger.log(e);
                return null;
            }
            return result;
        }

 读取xlsx文件：

 const string connectStr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
        public string ReadXlsxFileToEntityList(string filePath, String fileName, List<StudentEntity> stuList)
        {
            String fileAllName = filePath + "\\" + fileName;
            string result = "S";
            FileInfo fileInfo = new FileInfo(fileAllName);
            try
            {
                DataTable sheetTable = GetSheetTable(fileAllName);

                //只需要取第一个Sheet的sheetName
                string sheetName = sheetTable.Rows[0][2].ToString();

                //读取Excel内容,将excel中的内容存在list中
                DataTable dataTable = GetDataTable(fileAllName, sheetName);
                result = GetFocList(dataTable, fileName, stuList);
            }
            catch (Exception e)
            {
                return "E_" + e.Message;
            }
            return result;
        }
        /// <summary>
        /// 根据文件名称和sheet读取文件内容
        /// </summary>
        /// <param name="fileName"></param>
        /// <param name="sheetName"></param>
        /// <returns></returns>
        public DataTable GetDataTable(string fileName, string sheetName)
        {
            DataTable dataTable = new DataTable();
            OleDbConnection dbConn = new OleDbConnection(string.Format(connectStr, fileName));

            try
            {
                dbConn.Open();

                OleDbCommand dbCmd = new OleDbCommand();
                dbCmd.Connection = dbConn;
                dbCmd.CommandText = "select * from [" + sheetName + "] ";
                dbCmd.CommandType = CommandType.Text;
                OleDbDataAdapter dbApt = new OleDbDataAdapter(dbCmd);
                dbApt.Fill(dataTable);

            }
            finally
            {
                dbConn.Close();
            }
            return dataTable;
        }
        /// <summary>
        /// 根据文件名称获取文件中所有的sheetname
        /// </summary>
        /// <param name="filePath"></param>
        /// <returns></returns>
        public DataTable GetSheetTable(string filePath)
        {
            OleDbCommand dbCmd = new OleDbCommand();
            OleDbConnection dbConn = new OleDbConnection(string.Format(connectStr, filePath));
            DataTable sheetTable = null;
            try
            {
                dbConn.Open();
                //dbTable装载了所有的sheetneame
                sheetTable = dbConn.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });

                dbConn.Close();
            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
            finally
            {
                dbConn.Close();
            }
            return sheetTable;
        }
        /// <summary>
        /// 将dataTable转换为entityList
        /// </summary>
        /// <param name="dataTable"></param>
        /// <param name="fileName"></param>
        /// <returns></returns>
        public String GetFocList(DataTable dataTable, String fileName, List<StudentEntity> stuList)
        {
            var result = "S";
            if (dataTable.Rows.Count > 0)
            {
                for (int i = 0; i < dataTable.Rows.Count; i++)
                {
                    try
                    {
                        //不读取文件头
                        if (dataTable.Rows[i][0].ToString().Trim().Contains("学号"))
                        {
                            continue;
                        }
                        StudentEntity entity = new StudentEntity();
                        entity.fileName = fileName;//文件名
                        entity.no = dataTable.Rows[i][0].ToString().Trim();//学号
                        entity.name = dataTable.Rows[i][1].ToString().Trim();//姓名
                        stuList.Add(entity);
                    }
                    catch (Exception e)
                    {
                        throw new Exception(e.Message + "   " + i + "   " + dataTable.Rows[i]);
                    }
                }
            }
            return result;
        }