c# - Load implementation based on a parameter -

i have problem:

in c# i'm making program should connect various databases (sqlite, sql server compact, ms access, etc). set in app.config parameter called "dbtype" (it 1 sqllite, 2 sql server compact, 3 ms access, etc.). parameter should changed user while program running, dropdown menu or this.

then program reads parameter , creates instance of implementation of database interface (idatabase) corresponds chosen database.

the code is:

class objectdatabasecreator     {         protected objectdatabase objectdb;         protected object objectdao;         protected int dbtype;         protected string dbname;          public objectdatabasecreator()         {         }          public objectdatabasecreator(string dbname)         {             this.dbtype = objectconfiguration.getdbtype();             this.dbname = dbname;         }          public objectdatabase getobjectdatabase()         {             //1 - sqlite; 2-sqlserver compact; 3-sqlserver express; 4-ms access               switch (dbtype)             {                   case 1:                     objectdb = new objectdatabase(new database_impl_1(dbname));                     break;                  case 2:                     objectdb = new objectdatabase(new database_impl_2(dbname));                     break;                  case 3:                     objectdb = new objectdatabase(new database_impl_3(dbname));                     break;                  case 4:                     objectdb = new objectdatabase(new database_impl_4(dbname));                     break;             }              return objectdb;         }         } 

well, seems works know if there possibility make easier add databases, mean, if there db should modify class, recompile, etc.

and how instantiate other implementation bll classes, let's person, customer, etc ? these changes , should add more classes.

thanks, trav

take @ mef... can useful because add notion of catalog. defines many idatabaseimplemention class want in assemblies located in folder, , mef allow "import" found classes.

mef included in .net framework (from v4), there many other framework can job.