Phonegap没有互联网警报弹出问题

Question

我在网上搜索，当应用程序打开时告诉连接类型时，我得到了这个脚本。

<script type="text/javascript" src="cordova-2.5.0.js"></script>
<script type="text/javascript" charset="utf-8">

// Wait for PhoneGap to load
// 
document.addEventListener("deviceready", onDeviceReady, false);

// PhoneGap is loaded and it is now safe to make calls PhoneGap methods
//
function onDeviceReady() {
    checkConnection();
}

function checkConnection() {
    var networkState = navigator.network.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.NONE]     = 'No network connection';

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

</script>

但是我想要它做的是在没有互联网的情况下显示警报，所以我找到了一个脚本，它有一个条件语句，但是它不能工作。

var networkState = navigator.network.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.NONE]     = 'No network connection';

if ((states[networkState]) == states[Connection.NONE])
{
alert("Please check your internet connectivity and try again"); 
}

请有人指点我的出路，我也有一份我提交的表格，如果没有网上提交，我希望这份表格也能返回到同一页。

<form id="loginform" name="loginform" method="POST" action="http://mysite/login.php">

Answer 1

我没有将states[]值分配给字符串，而是使用true/false，并且知道NONE和UNKOWN都是我设置的没有连接的指示器：

    states[Connection.UNKNOWN]  = false;
    states[Connection.ETHERNET] = true;
    states[Connection.WIFI]     = true;
    states[Connection.CELL_2G]  = true;
    states[Connection.CELL_3G]  = true;
    states[Connection.CELL_4G]  = true;
    states[Connection.CELL]     = true;
    states[Connection.NONE]     = false;

然后你就可以：

if (states[networkState] === false) {
    //do something
 }

Answer 2

如果连接到“脱机”事件，然后在事件触发时显示未连接的消息/警报，则可能是更好的选择。当“deviceready”事件发生时，您可以在显示消息的同时使用此信息。

请确保安装了org.apache.cordova.network-information插件，以使这些插件都能正常工作。

当先前连接的设备失去网络连接，以致应用程序无法再访问Internet时，脱机事件将触发。它依赖于与Connection相同的信息，并在connection.type的值变为NONE时触发。

document.addEventListener("offline", onOffline, false);

function onOffline() {
    // Handle the offline event
}

参考： https://github.com/apache/cordova-plugin-network-information/blob/master/doc/index.md#offline