It's definitely a bad idea. That said, it looks like it's probably possible. Something like (untested):
var appDir:File = File.applicationDirectory; // uses app: URI, can't be written to
var appPath:String = appDir.nativePath;
var writeableAppDir:File = new File(appPath);
var newFile:File = writeableAppDir.resolvePath("writeme.txt");
The nativePath
and applicationDirectory
documentation in the File
class are full of warnings against this. Follow them.
From the docs:
Modifying content in the application
directory is a bad practice, for
security reasons. If you want to store
application-specific data, consider
using the application storage
directory
(File.applicationStorageDirectory). If
you want any of the content in the
application storage directory to have
access to the application-priveleged
functionality (AIR APIs), you can
expose that functionality by using a
sandbox bridge.