mui - 滑动置顶

var scroll = mui('.mui-scroll-wrapper').scroll();

document.querySelector('.mui-scroll-wrapper').addEventListener('scroll', function(e) {

var top = scroll.y;

if(top > -190) {

$scope.showTop = 1;

$scope.$apply()

} else {

$scope.showTop = 2;

$scope.$apply()

}

})