javascript - Check network connection via Firefox Extension

Question

Is there a possibility to check the connection to the network in a Firefox extension? I just want to know if the user is Online or Offline.

I've already tried navigator.online, but it doesn't work.

Answer 1

https://developer.mozilla.org/en-US/docs/Online_and_offline_events是您正在寻找的。

现在我会漫无目的地获得超过 30 个字符，感谢 stackoverflow。

Answer 2

据我所知，Firefox 不知道我是否切断了网络连接。所以我创建了一个小的 XMLHttpRequest (XHR) 来设置一个布尔值：

var netOnline; 

function createXMLHttpRequest() {
    return Components.classes["@mozilla.org/xmlextras/xmlhttprequest;1"]
       .createInstance(Components.interfaces.nsIXMLHttpRequest);    
}

function issueRequest() {
    var req = createXMLHttpRequest();
    req.open("GET", "http://google.com", true);
    req.timeout = 1000; // ms 
    // online
    req.addEventListener("load", function(event) {
        netOnline = true; 
    });
    // timeout -> offline
    req.addEventListener("timeout", function(event) {
        netOnline = false; 
    }); 
    // error -> offline
    req.addEventListener("error", function(event) {
        netOnline = false; 
    });
    req.send();
};

它工作正常。无论如何感谢您的帮助！