<wx-open-launch-weapp id="launch-btn"

                       appid="wxf643b9a074d3b35b"

                       path="pages/home/home?env-version=trial">

     <script type="text/wxtag-template">

         <style>.btn { padding: 12px }</style>

         <button class="btn">打开小程序</button>

     </script>

 </wx-open-launch-weapp>

 <script>

     var btn = document.getElementById('launch-btn');

     btn.addEventListener('launch', function (e) {

         console.log('success');

     });

     btn.addEventListener('error', function (e) {

         console.log('fail', e.detail);

     });

 </script>