How to detect current profile for XUL application?

标题： 如何获得XUL应用的当前profile，希望这篇英文日志能够帮到惯用英语搜索的人

When we launch our XUL application in multiple profiles mode, we may need to know which profile it works on.

Mozilla provides the interfaces as nsIToolkitProfileService to get current profile by reading the attribute "selectedProfile". But in some cases, it doesn't work.

For example, we launch XUL as "

xulrunner.exe -no-remote -profile <profile path or name>

", you can't get the right profile, it always return the default profile configured in file "

//$USERPROFILE\Application Data\$vendor\$appname\Profiles\$random.default

".

I solved this problem by detecting the folder name of the profile root directory. As for the same reason, you can't get the folder from nsIToolkitProfileService. But, we can get current profile root dir, from the File API. For example,

var dirService = Components.classes["@mozilla.org/file/directory_service;1"].getService(Components.interfaces.nsIProperties);
var profDir = dirService.get("ProfD", Components.interfaces.nsIFile);
var profName = profDir.leafName;

Simple， but it works well. ;)