更新时间2021-12-08 01:31:24
class DBConnection { private mysqlConnection connection; // public mysqlConnection connection; private string connectionStr; public DBConnection() { try { connectionStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString; connection = new MySqlConnection(connectionStr); } catch (Exception exception) { throw new Exception("DBConnection Constructor:" + exception.Message); } } public DataSet Select() { try { if (connection != null) { connection.Open(); } string cmdStr = "Select * from t_family"; MySqlCommand sqlCmd = new MySqlCommand(cmdStr, connection); MySqlDataAdapter sda = new MySqlDataAdapter(sqlCmd); DataSet ds = new DataSet(); sda.Fill(ds, "t_family"); return ds; } catch (Exception exception) { throw new Exception("SelectMethod:" + exception.Message); } finally { connection.Close(); } } }以上代码中提示“connection”没有定义,怎么回事
单单这段代码,在我的VS中没有任何错(只是没有入口程序),你检查下项目的其它部分。