ado读取excel

    public static class ExcelHelper
    {
        /// <summary>
        /// 读取所有的表(每个sheet映射为一个表)
        /// </summary>
        /// <param name="filepath"></param>
        /// <returns></returns>
        public static System.Collections.Generic.List<string> GetTables(string filepath)
        { 
            List<string> r=new List<string>();
            if (File.Exists(filepath))
            {
                //string connStr="Provider=Microsoft.Jet." + "OLEDB.4.0;Extended Properties=\"Excel 8.0\";Data Source=" + filepath;
                string connStr = "Provider=Microsoft.ACE.OLEDB.12.0;data source=" + filepath + ";Extended Properties='Excel 12.0 Xml;HDR=YES'";
                using (OleDbConnection conn = new OleDbConnection(connStr))
                {
                    conn.Open();
                    DataTable dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
                    for (int i = 0; i < dt.Rows.Count; i++)
                    {
                        r.Add(dt.Rows[i][2].ToString().Trim());
                    }
                }
            }
            return r;
        }

        /// <summary>
        /// 读取表中的数据
        /// </summary>
        /// <param name="filepath"></param>
        /// <param name="tableName">表名</param>
        /// <returns></returns>
        public static DataTable GetTableData(string filepath,string tableName)
        {
            DataTable r = new DataTable();
            if (File.Exists(filepath))
            {
                //string connStr = "Provider=Microsoft.Jet." + "OLEDB.4.0;Extended Properties=\"Excel 8.0;HDR=FALSE;IMEX=1\";Data Source=" + filepath;
                string connStr = "Provider=Microsoft.ACE.OLEDB.12.0;data source=" + filepath + ";Extended Properties='Excel 12.0 Xml;HDR=YES'";
                using (OleDbConnection conn = new OleDbConnection(connStr))
                {
                    conn.Open();
                    string sql = "select * from [" + tableName+ "]";
                    OleDbCommand oc = new OleDbCommand(sql, conn);
                    OleDbDataAdapter oda = new OleDbDataAdapter(oc);
                    oda.Fill(r);
                }
            }
            return r;
        }

        /// <summary>
        /// 读取表中的数据
        /// </summary>
        /// <param name="filepath"></param>
        /// <param name="tableIndex">表索引，几第n个表</param>
        /// <returns></returns>
        public static DataTable GetTableData(string filepath, int tableIndex)
        {
            var ts= GetTables(filepath);
            if (ts.Count > tableIndex)
            {
                string tableName = ts[tableIndex];
                DataTable r = new DataTable();
                if (File.Exists(filepath))
                {
                    //string connStr = "Provider=Microsoft.Jet." + "OLEDB.4.0;Extended Properties=\"Excel 8.0;HDR=FALSE;IMEX=1\";Data Source=" + filepath;
                    string connStr = "Provider=Microsoft.ACE.OLEDB.12.0;data source=" + filepath + ";Extended Properties='Excel 12.0 Xml;HDR=YES'";
                    using (OleDbConnection conn = new OleDbConnection(connStr))
                    {
                        conn.Open();
                        string sql = "select * from [" + tableName + "]";
                        OleDbCommand oc = new OleDbCommand(sql, conn);
                        OleDbDataAdapter oda = new OleDbDataAdapter(oc);
                        oda.Fill(r);
                    }
                }
                return r;
            }
            else
            {
                return null;
            }
        }

        /// <summary>
        /// 获取表结构(表的字段)
        /// </summary>
        /// <param name="filepath"></param>
        /// <param name="tableName"></param>
        /// <returns></returns>
        public static System.Collections.Generic.List<string> GetTableFields(string filepath, string tableName)
        {
            List<string> r=new List<string>();
            if (File.Exists(filepath))
            {
                //string connStr = "Provider=Microsoft.Jet." + "OLEDB.4.0;Extended Properties=\"Excel 8.0;HDR=FALSE;IMEX=1\";Data Source=" + filepath;
                string connStr = "Provider=Microsoft.ACE.OLEDB.12.0;data source=" + filepath + ";Extended Properties='Excel 12.0 Xml;HDR=YES'";
                using (OleDbConnection conn = new OleDbConnection(connStr))
                {
                    conn.Open();
                    string sql = "select * from [" + tableName + "] where 1=2";
                    OleDbCommand oc = new OleDbCommand(sql, conn);
                    OleDbDataAdapter oda = new OleDbDataAdapter(oc);
                    DataTable dt = new DataTable();
                    oda.Fill(dt);
                    for (int i = 0; i < dt.Columns.Count; i++)
                    {
                        r.Add(dt.Columns[i].Caption);
                    }
                }
            }
            return r;
        }
    


    }