使用预加载加载扫码界面，扫描的动画无法正常显示

mui.plusReady(function() {  
        webview_detail = mui.preload({  
            url: '../barcode/barcode_scan.html',  
            id: 'barcode_scan.html'  
        });  
    });  
function open_detail() {  
        //若详情页尚未预加载完成，则延时等待再执行  
        if(!webview_detail) {  
            setTimeout(function() {  
                open_detail(salesorder);  
            }, 100);  
        }  
        //触发子窗口变更新闻详情  
        mui.fire(webview_detail, 'get_detail', {});  
        setTimeout(function () {  
            webview_detail.show("slide-in-right", 300);  
        },150);  
    }  

    mui('.mui-bar').on('tap', '[data-url]', function() {  
        open_detail();  
    });

<script type="text/javascript">  
            scan = null; //扫描对象    
            var blist = [];  
            mui.plusReady(function() {  
                document.addEventListener('get_detail', function(){  
                    startRecognize();  
                });  
            });  
            mui.init({  
                beforeback: function() {  
                    //获得列表界面的webview  
                    var list = plus.webview.getWebviewById('deliveryDetail.html');  
                    //触发列表界面的自定义事件（refresh）,从而进行数据刷新  
                    mui.fire(list, 'barcode', {  
                        blist: blist  
                    });  
                    //返回true，继续页面关闭逻辑  
                    return true;  
                },  
            });  

            function startRecognize() {  
                try {  
                    var filter = [  
                        plus.barcode.CODE128  
                    ];  
                    //扫描控件构造    
                    scan = new plus.barcode.Barcode('bcid', filter);  
                    scan.onmarked = onmarked;  
                    scan.onerror = onerror;  
                    scan.start();  
                } catch(e) {  
                    mui.toast("出现错误啦:\n" + e);  
                }  
            };  

            function onmarked(type, result) {  
                var w = plus.nativeUI.showWaiting("请等待，正在办理");  
                var n = 2;  
                var text = '';  
                switch(type) {  
                    case plus.barcode.CODE128:  
                        type = 'CODE128';  
                        break;  
                }  
                barCodeJudge(result);  
                var t = setInterval(function() {  
                    n--;  
                    w.setTitle("请稍等\n" + n + "秒后可以重新扫描");  
                    if (n <= 0) {  
                        n = 2;  
                        w.close();  
                        scan.start();  
                    }  
                }, 1000);  
            };  

            // 从相册中选择二维码图片     
            function scanPicture() {  
                plus.gallery.pick(function(path) {  
                    plus.barcode.scan(path, onmarked, function(error) {  
                        plus.nativeUI.alert("无法识别此图片");  
                    });  
                }, function(err) {  
                    mui.toast("用户取消操作");  
                });  
            }  

            function barCodeJudge(result){  
                if(blist.length < 1){  
                    blist.push(result);  
                }else{  
                    if($.inArray(result, blist) == -1){  
                        blist.push(result);  
                    }else{  
                        mui.toast("条码重复，请重新扫描");  
                    }  
                }  
            }  
        </script>