xml - XDocument.Save(string) not available -

i'm using vs 2012 express windows 8.i want load xml file, modify content , save disk.

up now, i've been using linq xml , i've been able load file, change node information.

i want save file disk using xdocument.save(string) method intellisense not include method though documented in online documentation.

any idea why?

thanks

---update---

here's i'm trying do

string questionsxmlpath; xdocument xmldocquestions = null; storagefile file = null;  public mainpage() {     this.initializecomponent();      questionsxmlpath = path.combine(package.current.installedlocation.path, "assets/template.xml");     xmldocquestions = xdocument.load(questionsxmlpath); }  private async void somecodeheretopopulatecontrols() {     // code populates controls on window edit xml nodes. }   private async void button_click_3(object sender, routedeventargs e) {     xelement elequestion =         (from el in xmldocquestions.descendants("question")         (string)el.element("id") == txtid.text         select el).firstordefault();      elequestion.elements("description").firstordefault().replacewith(txtdescription.text);      xmldocquestions.save(questionsxmlpath);  // error here , can't compile } 

you'll need use windows.storage apis. in sandboxed , asynchronous world of windows 8, you'll find 2 significant differences in dealing file storage:

1. the application can programmatically access data "local storage" application unless end-user has granted specific permission app store/read elsewhere in file system (via file , folder pickers)

2. reading , writing files asynchronous operation, you'll find of file access methods ending in "async" , you'll use (typically) async/await pattern leverage them

take @ file access , permissions in windows store apps topic on windows dev center more details file access sample.

in specific case, you'll end writing xdocument.tostring() desired output file using techniques shown in article , code sample cited above.

by way, more holistic , measured approach learning file system (as other concepts unique windows store programming), (free) microsoft app builder program great way spin up.