//.方法一：采用OleDB读取EXCEL文件：         //打开excel 返回指定表中的所有数据        public DataSet ExcelToDS(string Path)        {            string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + Path + ";" + "Extended Properties=Excel 8.0;";            System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection(strConn);            conn.Open();            string strExcel = "";            System.Data.OleDb.OleDbDataAdapter myCommand = null;            DataSet ds = null;            strExcel = "select * from [sheet1$]";            myCommand = new System.Data.OleDb.OleDbDataAdapter(strExcel, strConn);            ds = new DataSet();            myCommand.Fill(ds, "table1");            return ds;        }        //对于EXCEL中的表即sheet([sheet1$])如果不是固定的可以使用下面的方法得到          public DataTable ExcelToDT(string Path)        {            string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + Path + ";" + "Extended Properties=Excel 8.0;";            System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection(strConn);            DataTable schemaTable = conn.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables, null);            string tableName = schemaTable.Rows[0][2].ToString().Trim();            return schemaTable;        }        //写入excel        public void DSToExcel(string Path, DataSet oldds)        {                       //先得到汇总EXCEL的DataSet 主要目的是获得EXCEL在DataSet中的结构             string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source =" + Path + ";Extended Properties=Excel 8.0";            System.Data.OleDb.OleDbConnection myConn = new System.Data.OleDb.OleDbConnection(strCon);            string strCom = "select * from [Sheet1$]";            myConn.Open();            System.Data.OleDb.OleDbDataAdapter myCommand = new System.Data.OleDb.OleDbDataAdapter(strCom, myConn);            System.Data.OleDb.OleDbCommandBuilder builder = new System.Data.OleDb.OleDbCommandBuilder(myCommand);            //QuotePrefix和QuoteSuffix主要是对builder生成InsertComment命令时使用。             builder.QuotePrefix = "[";     //获取insert语句中保留字符（起始位置）             builder.QuoteSuffix = "]"; //获取insert语句中保留字符（结束位置）             DataSet newds = new DataSet();            myCommand.Fill(newds, "Table1");            for (int i = 0; i < oldds.Tables[0].Rows.Count; i++)            {                //在这里不能使用ImportRow方法将一行导入到news中，因为ImportRow将保留原来DataRow的所有设置(DataRowState状态不变)。               // 在使用ImportRow后newds内有值，但不能更新到Excel中因为所有导入行的DataRowState != Added            DataRow nrow = newds.Tables["Table1"].NewRow();                for (int j = 0; j < newds.Tables[0].Columns.Count; j++)                {                    nrow[j] = oldds.Tables[0].Rows[i][j];                }                newds.Tables["Table1"].Rows.Add(nrow);            }            myCommand.Update(newds, "Table1");            myConn.Close();        }