没有互联网连接时的自定义通知

I have developed and packaged an offline Cordova-based HTML5 App for Android. It works fine, and some of the resources are accessed locally without an internet connection while other require an internet connection. A problem kicks in when the internet connection is down because it displays a Webpage, not available error together with the URL.

I have tried adding this to my HTML page, but it does not work

<img src='http://www.example.com/mobile/index.html' onerror='alert("Connection dead");' />

What problem is there with the above code?

Why don't you use cordova network plugin to test connectivity?

cordova plugin add cordova-plugin-network-information

Github - https://github.com/apache/cordova-plugin-network-information

Simple example -

function checkConnection() {
    var networkState = navigator.connection.type;

    var states = {};
    states[Connection.UNKNOWN]  = 'Unknown connection';
    states[Connection.ETHERNET] = 'Ethernet connection';
    states[Connection.WIFI]     = 'WiFi connection';
    states[Connection.CELL_2G]  = 'Cell 2G connection';
    states[Connection.CELL_3G]  = 'Cell 3G connection';
    states[Connection.CELL_4G]  = 'Cell 4G connection';
    states[Connection.CELL]     = 'Cell generic connection';
    states[Connection.NONE]     = 'No network connection';

    alert('Connection type: ' + states[networkState]);
}

checkConnection();