Donghy的博客直接贴代码，退出在ios是无效的。。
别的直接看代码吧
利用的是webview 的back等方法
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
<title></title>
</head>
<body>
<script type="text/javascript" charset="utf-8">
var ws=null,nw=null;
function plusReady(){
ws=plus.webview.currentWebview();
nw=plus.webview.create("http://weibo.com/dhnetwork");
ws.append(nw);
plus.key.addEventListener("backbutton",function(){
//查询Webview窗口是否可后退
nw.canBack( function(e){
var canback=e.canBack;
if(canback){
nw.back();
}else{
back();
}
});
});
}
var first = null;
var back = function() {
if (!first) {
first = (new Date()).getTime();
plus.nativeUI.toast('再按一次退出应用');
setTimeout(function() {
first = null;
}, 1000);
} else {
if ((new Date()).getTime() - first < 1000) {
plus.runtime.quit();
}
}
}
if(window.plus){
plusReady();
}else{
document.addEventListener("plusready",plusReady,false);
}
</script>
</body>
</html>