在微信开发者平台上可以显示，但是放到真机上却看不见?

$scope.src_url=$(".baby_photo:first").attr("src");
$(".bgmodal").css("height",$("article").height());
$(".bg_babyShare").attr("style","height:"+$('article').height()+"px;background-image:url("+$scope.src_url+");background-position: center;background-size:auto "+$('article').height()+"px;");
alert($(".bg_babyShare").height())