Be sure that `xe` is your `Service Name`. If the connection is successfull but you have this exception `SQLNestedException: Cannot create PoolableConnectionFactory (Io exception: The Network Adapter could not establish the connection) at` " you must have an incompatible version of JDBC, install the correct one: http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-10201-088211.html

What is the code inside the method: initSystemPros(); Are you sure 1521 is your port?

Hi, i personally use Delphi XE https://www.embarcadero.com/products/delphi/starter[^] but Xamarin must be a good option too. http://xamarin.com/platform[^]

Read Google Android documentation http://developer.android.com/training/index.html Write your first app: http://developer.android.com/training/basics/firstapp/index.html[^]

Hi, be more specific with your question and post some code.

must be an int, read the reference of setBackgroundColor method:

void android.view.View.setBackgroundColor(int color)