My GUI desktop-based WPF 4.0 (C# .Net 4.0) program works with SQL Server database. Each time when I run my application it creates a connection to SQL Server via ADO.NET Enti
@Damian Leszczyński - Vash's answer pretty much covers the 4 specific questions you asked. For your final question on Application.Exit(), that's an event you can subscribe to, not a method that you can call. It should be used like this:
Application.Current.Exit += CurrentOnExit;
//this.Exit += CurrentOnExit; would also work if you're in your main application class
...
private void CurrentOnExit(object sender, ExitEventArgs exitEventArgs)
{
//do some final stuff here before the app shuts down
}