读取Excel中数据

#region 读取导入Excel数据

    /// <summary>
    /// 
    /// </summary>
    /// <param name="filename"></param>
    /// <param name="fields"></param>
    /// <returns></returns>
    public DataSet ReadDataFromExcel(string filename, string fields)
    {
        DataSet ds = new DataSet();

        try
        {
            string cnn = string.Empty;

            string ext = Path.GetExtension(filename).ToLower();

            if (ext == ".xls")
            {
                cnn = "Provider = Microsoft.Jet.OLEDB.4.0; Data Source = " + filename + ";Extended Properties=" + (char)34 + "Excel 8.0;HDR=Yes;IMEX=1;" + (char)34;
            }
            else if (ext == ".xlsx")
            {
                cnn = "Provider = Microsoft.ACE.OLEDB.12.0; Data Source = " + filename + ";Extended Properties=" + (char)34 + "Excel 12.0;HDR=Yes;IMEX=1;" + (char)34;
            }
            else
            {
                throw new Exception("读取失败，非excel文件格式。");
            }

            using (OleDbConnection connection = new OleDbConnection(cnn))
            {
                connection.Open();

                DataTable tables = connection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });

                foreach (DataRow row in tables.Rows)
                {
                    string table = row["TABLE_NAME"].ToString();
                    DataTable dt = ReadEachExcelSheetData(connection, table, fields);
                    if (dt != null)
                    {
                        ds.Tables.Add(dt.Copy());
                    }
                }

            }

            return ds;
        }
        catch (Exception ex)
        {
            throw new Exception("数据文件或者内容格式有严重错误(" + ex.Message + ")，请检查！");
        }
    }

    public DataTable ReadEachExcelSheetData(OleDbConnection connection, string table, string fields)
    {
        try
        {
            string sql = string.Empty;

            string query = string.Empty;

            if (fields.IndexOf(',') > 0)
            {
                foreach (string column in fields.Split(','))
                {
                    query += "[" + column + "],";
                }
                query = query.Trim(',');
            }
            else
            {
                query = fields;
            }

            sql = @"
                        SELECT 
                                {0}
                        FROM 
                                [{1}]
                        ";

            sql = string.Format(sql, query, table);

            DataSet ds = new DataSet();
            OleDbDataAdapter adapter = new OleDbDataAdapter(sql, connection);
            adapter.Fill(ds, table);

            if (ds != null && ds.Tables.Count > 0 && ds.Tables[0].Rows.Count > 0)
            {
                return ds.Tables[0];
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }

        return null;

    }

    private DataSet GetDataFromExcel(string filename,string fields)
    {
        DataSet ds = new DataSet();

        string cnn = string.Empty;

        string ext = Path.GetExtension(filename).ToLower();

        if (ext == ".xls")
        {
            cnn = "Provider = Microsoft.Jet.OLEDB.4.0; Data Source = " + filename + ";Extended Properties=" + (char)34 + "Excel 8.0;HDR=Yes;IMEX=1;" + (char)34;
        }
        else if (ext == ".xlsx")
        {
            cnn = "Provider = Microsoft.ACE.OLEDB.12.0; Data Source = " + filename + ";Extended Properties=" + (char)34 + "Excel 12.0;HDR=Yes;IMEX=1;" + (char)34;
        }
        else
        {
            throw new Exception("读取失败，非excel文件格式。");
        }

        using (OleDbConnection connection = new OleDbConnection(cnn))
        {
            connection.Open();

            DataTable tables = connection.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });

            string tableName = tables.Rows[0]["TABLE_NAME"].ToString();

            string sql = "select * from [{0}]";

            sql = string.Format(sql, tableName);

            OleDbCommand command = connection.CreateCommand();
            command.CommandText = sql;

            OleDbDataAdapter adapter = new OleDbDataAdapter(command);
            adapter.Fill(ds);

            return ds;

        }
    }

    #endregion