JavaScript中防止微信浏览器被整体拖动的方法

html
 head
 title 微信拖动测试
 meta(charset="utf-8")
 meta(name="viewport", content="initial-scale=1, maximum-scale=1, minimum-scale=1")
 link(rel='stylesheet', href='/stylesheets/style.css')
 script(src="http://apps.bdimg.com/libs/zepto/1.1.4/zepto.min.js")
 body
 #container
 .header
 | header
 .page
 .box box1 in page
 .box box2 in page
 .box box3 in page
 .box.bottom box4 in page
 script.
 $(function() {
 var startY, endY;
 var box_height = $('#container').height();
 $('.page').on('touchstart', function(event) {
 event.stopPropagation();
 startY = event.touches[0].pageY;
 });
 $('.page').on('touchmove', function(event) {
 event.stopPropagation();
 var endY = event.changedTouches[0].pageY;
 var changedY = endY - startY;
 var scroll_top = $('.page').scrollTop();
　　　　　　　　　 // 判断是否在顶部，且向下拖动
 if (scroll_top === 0 && changedY > 0) {
 event.preventDefault();
 }
　　　　　　　　　 // 判断是否在底部，且向上拖动
 var o = $('.bottom').offset();
 if (o.top + o.height === box_height && changedY < 0) {
 event.preventDefault();
 }
 });
　　　　　　　// header禁止拖动
 $('.header').on('touchmove', function(event) {
 event.preventDefault();
 });
 });

*{
 padding: 0;
 margin: 0;
}
#container{
 position: absolute;
 left: 0;
 top: 0;
 right: 0;
 bottom: 0;
 background-color: #efefef;
 color: #fff;
 text-align: center;
 font-size: 40px;
}
.header{
 position: absolute;
 left: 0;
 right: 0;
 height: 80px;
 line-height: 80px;
 background-color: #ddd;
}
.page{
 position: absolute;
 left: 0;
 right: 0;
 bottom: 0;
 top: 80px;
 background-color: #ccc;
 overflow-y: auto;
 -webkit-overflow-scrolling: touch;
}
.page > *{
 z-index: 1;
}
.box{
 width: 100%;
 height: 300px;
 line-height: 300px;
 box-sizing: border-box;
 border-bottom: 2px solid #fff;
}