一个ExcelHelper通用类，可用于读取或生成数据

读取或生成EXCEL数据的方法有很多，一般常见的有：

1.通过OFFICE EXCEL组件，优点：读取与生成EXCEL文件方便，缺点：服务器上必须安装OFFICE软件，且进程无法及时释放

2.通过第三方组件（比如：NPOI），优点：无需安装OFFICE软件，缺点：需要引入第三方组件，当然这个还是比较强的

3.通过把EXCEL当成数据库，连接后运用SQL语句读取，写入的话就自行拼接成HTML表格，优点：无需另外的组件，缺点：需要会SQL及拼接HTML表格较麻烦；

三种方法我都有用过，若开发BS网站程序，建议采用第二种、第三种方法，若开发CS结构，建议采用第一种或第二种；

以下是我针对BS端写的一个ExcelHelper通用类，可用于读取或生成数据，比较方便，技术原理是上述的第三种方法，代码如下，可能存在缺陷，高手见谅：

namespace ASOTS.Models{    public abstract class ExcelHelper    {        /// <summary>        /// 获取EXCEL中指定sheet内容        /// </summary>        /// <returns></returns>        public static DataTable GetTableFromExcel(string filePath, string fileExt, string tableName, int colsCount)        {            string connstr = null;            if (fileExt == ".xls")            {                connstr = "Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source =" + filePath + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1'";            }            else            {                connstr = "Provider = Microsoft.ACE.OLEDB.12.0 ; Data Source =" + filePath + ";Extended Properties='Excel 12.0;HDR=Yes;IMEX=1'";            }            using (OleDbConnection excelConn = new OleDbConnection(connstr))            {                excelConn.Open();                //获取EXCEL架构信息                DataTable schemaTable = excelConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new Object[] { null, null, null, "TABLE" });                //判断指定sheet名是否存在                DataView schemaView = new DataView(schemaTable);                schemaView.RowFilter = "TABLE_NAME='" + tableName + "$'";                schemaTable = schemaView.ToTable();                if (schemaTable != null && schemaTable.Rows.Count > 0)                {                    DataTable schemaTable_Cols = excelConn.GetOleDbSchemaTable(OleDbSchemaGuid.Columns, new object[] { null, null, tableName + "$", null });                    schemaView = new DataView(schemaTable_Cols);                    schemaView.RowFilter = "ORDINAL_POSITION<=" + colsCount.ToString();                    schemaView.Sort = "ORDINAL_POSITION asc";                    schemaTable_Cols = schemaView.ToTable();                    string selectCols = "";                    for (int i = 0; i < schemaTable_Cols.Rows.Count; i++)                    {                        selectCols += "," + schemaTable_Cols.Rows[i]["COLUMN_NAME"].ToString();                    }                    selectCols = selectCols.Substring(1);                    //查询sheet中的数据                    string strSql = "select " + selectCols + " from [" + tableName + "$]";                    OleDbDataAdapter da = new OleDbDataAdapter(strSql, excelConn);                    DataSet ds = new DataSet();                    da.Fill(ds, tableName);                    excelConn.Close();                    return ds.Tables[tableName];                }                else                {                    excelConn.Close();                    return null;                }            }        }        /// <summary>        /// 将数据模型集合对象生成HTML表格字符串        /// </summary>        /// <param name="data"></param>        /// <param name="tableAttributes"></param>        /// <param name="headers"></param>        /// <returns></returns>        public static string SetDataToHtmlTable(IEnumerable data, string tableAttributes, params KeyValuePair<string, string>[] headers)        {            StringBuilder htmlTableBuilder = new StringBuilder();            htmlTableBuilder.AppendFormat("<table {0}>", tableAttributes);            if (data.GetEnumerator().Current == null)            {                throw new Exception("没有获取到任何数据！");            }            Type t = data.GetEnumerator().Current.GetType();            string[] cellIndexs = new string[headers.Count()];            htmlTableBuilder.Append("<tr>");            for (int i = 0; i < headers.Count(); i++)            {                cellIndexs[i] = headers[i].Key;                htmlTableBuilder.AppendFormat("<th>{0}</th>", headers[i].Value);            }            htmlTableBuilder.Append("</tr>");            foreach (var item in data)            {                htmlTableBuilder.Append("<tr>");                for (int i = 0; i < cellIndexs.Length; i++)                {                    object pValue = t.GetProperty(cellIndexs[i]).GetValue(item, null);                    htmlTableBuilder.AppendFormat("<td>{0}</td>", pValue);                }                htmlTableBuilder.Append("</tr>");            }            htmlTableBuilder.Append("</table>");            return htmlTableBuilder.ToString();        }        /// <summary>        /// 将DataTable对象生成HTML表格字符串        /// </summary>        /// <param name="data"></param>        /// <param name="tableAttributes"></param>        /// <param name="headers"></param>        /// <returns></returns>        public static string SetDataToHtmlTable(DataTable dataTable, string tableAttributes, params KeyValuePair<string, string>[] headers)        {            StringBuilder htmlTableBuilder = new StringBuilder();            htmlTableBuilder.AppendFormat("<table {0}>", tableAttributes);            htmlTableBuilder.Append("<tr>");            for (int i = 0; i < headers.Count(); i++)            {                htmlTableBuilder.AppendFormat("<th>{0}</th>", headers[i].Value);            }            htmlTableBuilder.Append("</tr>");            foreach (DataRow row in dataTable.Rows)            {                htmlTableBuilder.Append("<tr>");                for (int i = 0; i < headers.Count(); i++)                {                    htmlTableBuilder.AppendFormat("<td>{0}</td>", row[headers[i].Key]);                }                htmlTableBuilder.Append("</tr>");            }            htmlTableBuilder.Append("</table>");            return htmlTableBuilder.ToString();        }    }    public class KeyValueList<TKey, TValue> : List<KeyValuePair<TKey, TValue>>    {        public void Add(TKey key, TValue value)        {            base.Add(new KeyValuePair<TKey, TValue>(key, value));        }    }}

调用方法如下：

//读数据DataTable resultTable = ExcelHelper.GetTableFromExcel(saveFilePath, fileExt, "data", 10);//生成表格（以下是MVC调用，WEBFORM同理）KeyValueList<string, string> headers = new KeyValueList<string, string>() {                         {"year","年 份"},                        {"month","月 份"},                        {"stage1count","一 阶"},                        {"stage2count","二 阶"},                        {"stage3count","三 阶"},                        {"stage4count","四 阶"},                        {"yearincount","一年内进厂"},                        {"stagetotalcount","基盘客户总数"},                        {"stage1rate","一阶占比"},                        {"stage2rate","二阶占比"},                        {"stage3rate","三阶占比"},                        {"stage4rate","四阶占比"}                };                string tableAttributes = "border='1' cellspacing='3' cellpadding='3'";                string htmlTable=ExcelHelper.SetDataToHtmlTable(model, tableAttributes, headers.ToArray());                byte[] b = System.Text.Encoding.UTF8.GetBytes(htmlTable);                return File(b, "application/vnd.ms-excel", string.Format("StageSummary_{0}_{1}_{2}.xls",orgcode,startym,endym));

其中：KeyValueList是我创建的一个集合类，主要用于生成表头，以及表头与数据列对应，之所以写成类，是因为若直接使用：List<KeyValuePair<TKey, TValue>>，则无法直接使用集合初始化器，就必需得一个一个的添加对象，有些繁琐，增加了ADD方法后，就可以直接用：new KeyValueList<string, string>() {{"",""},...}很方便，有人可能说为什么不用SortedDictionary等现有排序类，原因是SortedDictionary是基于Key排序，而此处是采用ADD的先后顺序来固定顺序的。