下拉刷新，在tabbar的子页面中，每次只在一个页面上有效

在tabbar中写了四个子页面，子页面中分别都使用了下拉刷新，可是每次测试的时候，下拉刷新只随机在一个页面上有效，请问是什么原因？有什么解决方法？

tabbar页面

    <nav class="mui-bar mui-bar-tab">  
            <a id="defaultTab" class="mui-tab-item mui-active" href="http://ask.dcloud.net.cn/index.html">  
                <span class="mui-icon mui-icon-home"></span>  
                <span class="mui-tab-label">首页</span>  
            </a>  
            <a class="mui-tab-item" href="http://ask.dcloud.net.cn/../Latest/index.html">  
                <span class="mui-tab-label">最新揭晓</span>  
            </a>  
            <a class="mui-tab-item" href="http://ask.dcloud.net.cn/../Explore/index.html">  
                <span class="mui-icon mui-icon-contact"></span>  
                <span class="mui-tab-label">发现</span>  
            </a>  
            <a class="mui-tab-item" href="http://ask.dcloud.net.cn/../List/index.html">  
                <span class="mui-icon mui-icon-gear"></span>  
                <span class="mui-tab-label">清单</span>  
            </a>  
            <a class="mui-tab-item" href="http://ask.dcloud.net.cn/../Mine/index.html">  
                <span class="mui-icon mui-icon-gear"></span>  
                <span class="mui-tab-label">我的</span>  
            </a>  
        </nav>  
        <script type="text/javascript" charset="utf-8">  

            var subpages = ['index.html', '../Latest/index.html', '../Explore/index.html', '../List/index.html', '../Mine/index.html'];  
            var subpage_style = {  
                top: '0px',  
                bottom: '50px'  
            };  
             //创建子页面，首个选项卡页面显示，其它均隐藏；  
            mui.plusReady(function() {  
                var self = plus.webview.currentWebview();  
                for (var i = 0; i < 5; i  ) {  
                    var sub = plus.webview.create(subpages[i], subpages[i], subpage_style);  
                    if (i > 0) {  
                        sub.hide();  
                    }  
                    self.append(sub);  
                }  
            });  
             //当前激活选项  
            var activeTab = subpages[0];  
             //         var title = document.getElementById("title");  
             //选项卡点击事件  
            mui('.mui-bar-tab').on('tap', 'a', function(e) {  
                var targetTab = this.getAttribute('href');  
                if (targetTab == activeTab) {  
                    return;  
                }  
                //显示目标选项卡  
                plus.webview.show(targetTab);  
                //隐藏当前;  
                plus.webview.hide(activeTab);  
                //更改当前活跃的选项卡  
                activeTab = targetTab;  
            });  
             //自定义事件，模拟点击“首页选项卡”  
            document.addEventListener('gohome', function() {  
                var defaultTab = document.getElementById("defaultTab");  
                //模拟首页点击  
                mui.trigger(defaultTab, 'tap');  
                //切换选项卡高亮  
                var current = document.querySelector(".mui-bar-tab>.mui-tab-item.mui-active");  
                if (defaultTab !== current) {  
                    current.classList.remove('mui-active');  
                    defaultTab.classList.add('mui-active');  
                }  
            });  
        </script>

子页面

    <header class="mui-bar mui-bar-nav">  
            <a class="mui-icon mui-icon-search mui-pull-left"></a>  
            <h1 class="mui-title">标题</h1>  
        </header>  
        <div class="mui-content">  

        </div>  
        <script>  
            mui.init({  
                subpages: [{  
                    url: 'index_.html',  
                    id: 'index_.html',  
                    styles: {  
                        top: '45px',  
                        bottom: '0px',  
                    }  
                }]  
            });  
        </script>  

子页面的刷新页面

               <div id="pullMine" class="mui-content mui-scroll-wrapper">  
            <div class="mui-scroll">  
                我的  
            </div>  
        </div>  
        <script>  
//下拉刷新  
mui.init({  
    pullRefresh: {  
        container: '#pullMine',  
        down: {  
            callback: pulldownRefresh  
        }  
    }  
});  
/**  
 * 下拉刷新具体业务实现  
 */  
function pulldownRefresh() {  
    setTimeout(function() {  

        mui('#pullrefresh').pullRefresh().endPulldownToRefresh(); //refresh completed  
    }, 1500);  
}  

</script>