and application logic of your Windows 8 app. For example, any events that occur are handled and dealt with in these code-behind files. In the XAML, you can connect a particular control to an event handler method, and in your code-behind file, you would have a method that handles that event if it is fired while your application is used. What does this application do? This application is very basic. It has a RichEditBox, two buttons for Open and Save and can determine whether a file is already open; and if so, when the "Save" button is pressed, the active file is saved instead of a dialogue being displayed to choose a location and file name for saving a new file with the contents of the RichEditBox. However, this isn't all - when you are about to show an open or save picker dialogue, you need to make sure the user is not in "snapped" mode (i.e. the application become snapped to 1/3 of the screen on the left or right). If you don't check this and either unsnap or prevent the dialogue from trying to appear, an exception will be thrown in your application and will cause your application to crash. You can force your application to become unsnapped prior to showing the dialogue which is what is done in this application. It's easy to do, too. What does the application look like? The end result is as shown below. Do bear in mind this is a demo tutorial