<div id="bar" contentEditable="false">文本文本</div>

<button id="copybtn" class="copycode">点击复制</button>

$('#copybtn').click(function () {

       var el = document.querySelector('#bar');

       var range = document.createRange();

       range.selectNodeContents(el);

       var selection = window.getSelection();

       selection.removeAllRanges();

       selection.addRange(range);

       document.execCommand('copy');

        alert("复制成功")

   });

   function get_ios8() {

        // 判断是否 iPhone 或者 iPod

       if ((navigator.userAgent.match(/iPhone/i) || navigator.userAgent.match(/iPod/i))) {

            // 判断系统版本号是否大于3小于8

           var version8 = Boolean(navigator.userAgent.match(/OS [3-8]_\d[_\d]* like Mac OS X/i));

            if (version8) {

               $('#copybtn').remove();

            }

       } else {

            return false;

       }

    }

  get_ios8();