[问题贴]mui.openWindow+自定义事件监听操作让alert()执行两次

仔细看，Alert函数执行了两次

共两个页面：index.html和detail.html,

detail.html为按钮设置了自定义事件监听(newsId)，触发alert.

在index.html点击按钮就会触发事件newsId,并用mui.openWindow()打开detail.html页面。

然后我有两个问题：

1. 就是上面提到的alert执行两次？

2. 就是有时候点击按钮并不会有任何操作，是文档没有加载完毕可能，有什么解决方法吗？

具体代码如下：

// ---index.html
 
<body>
    <header class="mui-bar mui-bar-nav">
            <h1 class="mui-title">新闻页面</h1>
    </header>
    <div class="mui-content">
        <a id="pen" class="mui-btn mui-btn-blue">钢笔事件</a>
        <a id="book" class="mui-btn mui-btn-blue">书籍事件</a>
        <a id="teacher" class="mui-btn mui-btn-blue">教师事件</a>       
    </div>
    <script src="js/mui.min.js"></script>
    <script type="text/javascript" charset="utf-8">
        mui.init({
            //初始化预加载详情页面
            preloadPages:[{
                id:'detail.html',
                url:'detail.html'
            }]
        });
        mui.plusReady(function () {
           alert('plusReady()执行成功!'); 
        });
 
        var detailPage = null;
        // 添加列表项的点击事件
        mui('.mui-content').on('tap','a',function(e) {
            var id = this.getAttribute('id');
            //获得详情页面
            if(!detailPage) {
                detailPage = plus.webview.getWebviewById('detail.html');
            }
            //触发详情页面的newsId事件
            mui.fire(detailPage,'newsId',{
                id:id
            });
            //打开详情页面
            mui.openWindow({
                id:'detail.html'
            });
        });
    </script>
</body>

//---detail.html
 
<body>
        <header class="mui-bar mui-bar-nav">
            <a class="mui-action-back mui-icon mui-icon-left-nav mui-pull-left"></a>
            <h1 class="mui-title">详情页</h1>
        </header>
        <div class="mui-content">
            <div id="showId"></div>
            <div class="mui-bar-footer mui-bar mui-text-center"><a class="mui-btn mui-btn-blue">回到新闻页</a></div>
        </div>
        <script src="js/mui.min.js"></script>
        <script type="text/javascript">
            mui.init();
            //添加newsId自定义时间监听
            window.addEventListener('newsId',function(event){
                //获得事件参数
                var id = event.detail.id;
                //将id显示在详情页上
                alert(id);  // 会出现两次是为什么？
                var showId = document.getElementById('showId');
                showId.innerText = id;
            });
 
            //添加列表点击事件
            mui('.mui-content').on('tap', 'a', function(e){
                mui.openWindow({
                    url:'index.html',
                    id:'index.html',
                    createNew:true       //重新出发index.html页面的plusReady()函数
                });
            });
        </script>
    </body>