NPOI读取Excel到集合对象

之前做过的项目中有个需要读取Excel文件内容的需求，因此使用NPOI实现，写下以下代码，这个只是一个代码段，还有很多地方需要优化，希望能对大家有所帮助

        public static IList<T> ReadListFromStream<T>(string fileName, Stream stream, bool ignoreFirstLine)

            where T : new()

        {

            string extendsion = Path.GetExtension(fileName).TrimStart('.');



            IWorkbook workBook = null;

            switch (extendsion)

            {

                case "xls":

                    workBook = new HSSFWorkbook(stream);

                    break;

                case "xlsx":

                    workBook = new XSSFWorkbook(stream);

                    break;

            }



            if (workBook == null || workBook.Count <= 0) { throw new NPOIException("Excel表格工作簿为空"); }



            IList<T> list = new List<T>();

            for (int i = 0; i < workBook.Count; i++)

            {

                ISheet sheet = workBook.GetSheetAt(i);



                if (sheet.PhysicalNumberOfRows > 0)

                {

                    if (!ignoreFirstLine)

                    {

                        //检查列是否与ExcelAttribute定义的一致

                        ValidTableHeader<T>(sheet);

                    }



                    for (int j = ignoreFirstLine ? 0 : 1; j < sheet.PhysicalNumberOfRows; j++)

                    {

                        var row = sheet.GetRow(j);



                        T entity = new T();



                        var propertys = typeof(T).GetProperties();



                        foreach (var p in propertys)

                        {

                            var excel = Attribute.GetCustomAttribute(p, typeof(ExcelAttribute)) as ExcelAttribute;



                            if (excel != null)

                            {

                                var cellValue = row.GetCell(excel.ColumnIndex);



                                if (cellValue == null || string.IsNullOrEmpty(cellValue.ToString()))

                                    throw new NPOIException(string.Format("第{0}行“{1}”不能为空", j + 1, excel.ColumnName));



                                string cellValueStr = cellValue.ToString();

                                if (p.PropertyType == typeof(int))

                                {

                                    int temp;

                                    if (!int.TryParse(cellValueStr, out temp))

                                        throw new NPOIException(string.Format("第{0}行“{1}”应为{2}类型", j + 1, excel.ColumnName, "整数"));

                                    p.SetValue(entity, temp, null);

                                }

                                else if (p.PropertyType == typeof(DateTime))

                                {

                                    DateTime temp;

                                    if (!DateTime.TryParse(cellValueStr, out temp))

                                        throw new NPOIException(string.Format("第{0}行“{1}”应为{2}类型", j + 1, excel.ColumnName, "时间"));

                                    p.SetValue(entity, temp, null);

                                }

                                else if (p.PropertyType == typeof(bool))

                                {

                                    bool temp;

                                    if (!bool.TryParse(cellValueStr, out temp))

                                        throw new NPOIException(string.Format("第{0}行“{1}”应为{2}类型", j + 1, excel.ColumnName, "布尔"));

                                    p.SetValue(entity, cellValueStr, null);

                                }

                                else if (p.PropertyType == typeof(string))

                                {

                                    p.SetValue(entity, cellValueStr, null);

                                }

                                else

                                {

                                    throw new NPOIException(string.Format("第{0}行“{1}”类型未知，请联系开发人员", j + 1, excel.ColumnName));

                                }

                            }

                        }

                        list.Add(entity);

                    }

                }

            }

            return list;

        }



        /// <summary>

        /// 检查表头与定义是否匹配

        /// </summary>

        /// <typeparam name="T"></typeparam>

        /// <param name="firstRow"></param>

        /// <returns></returns>

        private static void ValidTableHeader<T>(ISheet sheet) where T : new()

        {

            var firstRow = sheet.GetRow(0);



            var propertys = typeof(T).GetProperties();



            foreach (var p in propertys)

            {

                var excel = Attribute.GetCustomAttribute(p, typeof(ExcelAttribute)) as ExcelAttribute;



                if (excel != null)

                {

                    if (!firstRow.GetCell(excel.ColumnIndex).StringCellValue.Trim().Equals(excel.ColumnName))

                    {

                        throw new NPOIException(string.Format("Excel表格第{0}列标题应为{1}", excel.ColumnIndex + 1, excel.ColumnName));

                    }

                }

            }

        }

ExcelAttribute是自定义的一个特性类，主要在实体属性上标记，以确定该属性对应于Excel中的列名，列的索引

[AttributeUsage(AttributeTargets.Property)]

    public class ExcelAttribute : Attribute

    {

        private string _columnName;



        public string ColumnName

        {

            get { return _columnName; }

            set { _columnName = value; }

        }

        private int _columnIndex;



        public int ColumnIndex

        {

            get { return _columnIndex; }

            set { _columnIndex = value; }

        }



        public ExcelAttribute(string columnName)

        {

            this._columnName = columnName;

        }



        public ExcelAttribute(string columnName, int columnIndex)

        {

            this._columnName = columnName;

            this._columnIndex = columnIndex;

        }

    }