mui 选择器无法正常显示

                var cityPicker3 = new mui.PopPicker({  
                    layer: 3  
                });  
                cityPicker3.setData(cityData3);  

                var showCityPickerButton = doc.getElementById('AddRess');  
                var cityResult3 = doc.getElementById('cityResult3');  
                showCityPickerButton.addEventListener('tap', function(event) {  
                    cityPicker3.show(function(items) {  
                        cityResult3.innerText ="你选择的城市是:" + (items[0] || {}).text + " " + (items[1] || {}).text + " " + (items[2] || {}).text;  
                        //返回 false 可以阻止选择框的关闭  
                        //return false;  
                    });  
                }, false);  
            });  

同时在游览器中