"The idea behind Adobe AIR is to allow developers to use their
existing Adobe Flash, Adobe Flex, Hypertext Markup Language (HTML),
browser onto the desktop. The ActionScript Virtual Machine (AVM)
embedded in AIR makes this move possible, because it functions
similar to the Java virtual machine (JVM). When users have the AVM,
they can then run applications that have been compiled with the
amxmlc compiler. AIR applications are installed like any other
desktop application--through an installer. This installer even
checks to see if the user has the runtime installed and, if not,
prompts the user to install it.
"In making this move to the desktop, AIR applications are
granted privileges that are not available to their Web-based
counterparts. One such privilege is access to the local file
system. This article examines the AIR File application programming
interface (API), including some of the special directories defined
in the API as well as the pre-built user interface (UI) components
available in Adobe Flex Builder for working with the file system.
Finally, you'll learn how to build a simple application that uses
the File API to browse for and display an image file from your
local hard disk."