微信浏览器禁止页面下拉查看网址（不影响页面内部scroll）

var overscroll = function(el) {

  el.addEventListener('touchstart', function() {

    var top = el.scrollTop

      , totalScroll = el.scrollHeight

      , currentScroll = top + el.offsetHeight;

    //If we're at the top or the bottom of the containers

    //scroll, push up or down one pixel.

    //

    //this prevents the scroll from "passing through" to

    //the body.

    if(top === 0) {

      el.scrollTop = 1;

    } else if(currentScroll === totalScroll) {

      el.scrollTop = top - 1;

    }

  });

  el.addEventListener('touchmove', function(evt) {

    //if the content is actually scrollable, i.e. the content is long enough

    //that scrolling can occur

    if(el.offsetHeight < el.scrollHeight)

      evt._isScroller = true;

  });

}

overscroll(document.querySelector('.scroll'));

document.body.addEventListener('touchmove', function(evt) {

  //In this case, the default behavior is scrolling the body, which

  //would result in an overflow.  Since we don't want that, we preventDefault.

  if(!evt._isScroller) {

    evt.preventDefault();

  }

});