github（里有JQ写的）https://github.com/Aliceco/javascript-WX-masklayer

<!DOCTYPE html>
 <html lang="en">

 <head>

     <meta charset="UTF-8">

     <meta name="viewport" content="width=device-width, initial-scale=1"/>

     <title>微信弹出遮罩</title>

 </head>

 <body>

     <style type="text/css">

     *{margin:0; padding:0;}

     img{max-width: 100%; height: auto;}

     .test{height: 600px; max-width: 600px; font-size: 40px;}

     </style>

     <div class="test">

         <a href="http://mp.weixin.qq.com/mp/redirect?url=http://mobile.xinlianwang.com/android/distributor/DistributorApp.apk#weixin.qq.com#wechat_redirect ">有效跳转</a>

     </div>

     <script type="text/javascript">

         function is_weixin() {

             var ua = navigator.userAgent.toLowerCase();

             if (ua.match(/MicroMessenger/i) == "micromessenger") {

                 return true;

             } else {

                 return false;

             }

         }

         var isWeixin = is_weixin();

         var winHeight = typeof window.innerHeight != 'undefined' ? window.innerHeight : document.documentElement.clientHeight;

         function loadHtml(){

             var div = document.createElement('div');

             div.id = 'weixin-tip';

             div.innerHTML = '<p><img src="live_weixin.png" alt="微信打开"/></p>';

             document.body.appendChild(div);

         }

         

         function loadStyleText(cssText) {

             var style = document.createElement('style');

             style.rel = 'stylesheet';

             style.type = 'text/css';

             try {

                 style.appendChild(document.createTextNode(cssText));

             } catch (e) {

                 style.styleSheet.cssText = cssText; //ie9以下

             }

             var head=document.getElementsByTagName("head")[0]; //head标签之间加上style样式

             head.appendChild(style); 

         }

         var cssText = "#weixin-tip{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%;}";

         if(isWeixin){

             loadHtml();

             loadStyleText(cssText);

         }

     </script>

 </body>

 </html>