Null return from C# application settings file

Question

I am attempting to use this code:

 String MainDB = ConfigurationManager.AppSettings["MainDB"];
 MessageBox.Show(MainDB);
 String MailInfo = ConfigurationManager.AppSettings["MailInfo"];
 MessageBox.Show(MailInfo);
 String HousingIndexLocation = ConfigurationManager.AppSettings["HousingIndex"];
 MessageBox.Show(HousingIndexLocation);

to access values generated by this screen:

Everytime the values are returned null.

what am I missing in my implementation of these settings?

Answer 1

Try

String MainDB = Properties.Settings.Default.MainDB;
MessageBox.Show(MainDB);
String MailInfo = Properties.Settings.Default.MailInfo;
MessageBox.Show(MailInfo);
String HousingIndexLocation = Properties.Settings.Default.HousingIndex;
MessageBox.Show(HousingIndexLocation);