微信实现自动跳转到用其他浏览器打开指定APP下载

var ua = navigator.userAgent;
var isWeixin = !!/MicroMessenger/i.test(ua);

 #weixin-tip{display:none;position:fixed;left:0;top:0;background:rgba(0,0,0,0.8);filter:alpha(opacity=80);width:100%;height:100%;z-index:100;}
 #weixin-tip p{text-align:center;margin-top:10%;padding:0 5%;position:relative;}
 #weixin-tip .close{color:#fff;padding:5px;font:bold 20px/24px simsun;text-shadow:0 1px 0 #ddd;position:absolute;top:0;left:5%;}

 var is_weixin = (function(){return navigator.userAgent.toLowerCase().indexOf(‘micromessenger') !== -1})();
 window.onload = function() {
 var winHeight = typeof window.innerHeight != ‘undefined' ? window.innerHeight : document.documentElement.clientHeight; //兼容IOS，不需要的可以去掉
 var btn = document.getElementById(‘J_weixin');
 var tip = document.getElementById(‘weixin-tip');
 var close = document.getElementById(‘close');
 if (is_weixin) {
 btn.onclick = function(e) {
 tip.style.height = winHeight + ‘px'; //兼容IOS弹窗整屏
 tip.style.display = ‘block';
 return false;
 }
 close.onclick = function() {
 tip.style.display = ‘none';
 }
 }
 }