javascript - Cannot read InputStream from HttpListenerRequest -

i've been creating download manager receive file name , download link chrome extension.
in case decided use javascript background page send xmlhttprequest loopback , create simple server receive message background page this.

background.js

function showmessagebox(info, tab) {     var link = decodeuricomponent(info.linkurl);     var index = link.search(/[^/\\\?]+\.\w{3,4}(?=([\?&].*$|$))/);     var filename = link.substring(index);     alert("will download " + link + " soon\n file name : " + filename);     sendmessage(filename,link); } function sendmessage(filename, link) {     var xhr = new xmlhttprequest();     xhr.open("post","http://localhost:6230", false);     xhr.setrequestheader("content-type", "application/json; charset=utf-8");     var jsonstring = json.stringify({ filename: filename, downloadlink: link });     xhr.send(jsonstring); } 

and part of server.

    private void startreciever()     {         while (true)         {             var fileinfo = getfileinfo();             execute.onuithread(() => windowmanager.showdialog(                 new newdownloadviewmodel(windowmanager, eventaggregator, fileinfo, engine)));         }     }      private fileinfo getfileinfo()     {         using (var listener = new httplistener())         {             listener.prefixes.add("http://localhost:6230/");             listener.start();             var requestcontext = listener.getcontext();             /*var streamreader = new streamreader(requestcontext.request.inputstream, requestcontext.request.contentencoding);             string jsonstring = streamreader.readtoend();*/             var stream = requestcontext.request.inputstream;             byte[] buffer = new byte[10240];             var readbyte = stream.read(buffer, 0, 102400);             string ss = encoding.utf8.getstring(buffer, 0, readbyte);             // deserialize string object              return new fileinfo();         }     } 

i wonder why stream read return 0 when message sent.

finally, found forgot!

according same-origin policy, can't send http request server isn't same origin.
must use cross-origin xmlhttprequest communicate server isn't same origin.

to need request cross-origin permissions add hostname permissions section.
in case this.

"permissions": [ "contextmenus", "http://localhost/", "nativemessaging" ] 

now, can receive string , deserialize it.