如何用js檢測手機是否安裝某個app

標籤：download   load   key   number   class   word   immediate   index   0ms   

//html代碼中 的 a 標籤，以為例，預設的是調用weixin scheme，去開啟原生，如果沒有則跳轉到相應串連

　　　　<a href= "weixin://"  class = "btn-download" >立即開啟</a> 　　 　　　　 // 為btn-download 綁定事件，如果在500ms內，沒有解析到協議，那麼就會跳轉到下載連結 　　　　  var  appstore, ua = navigator.userAgent;          if (ua.match(/Android/i)){              appstore =  ‘market://search?q=com.singtel.travelbuddy.android‘ ;          }          if (ua.match(/iphone|ipod|ipad/)){              appstore =  "https://itunes.apple.com/cn/app/wei-xin/id414478124?mt=8&ign-mpt=uo%3D4" ;          }          function  applink(fail){               return  function (){                   var  clickedAt = + new  Date;                   // During tests on 3g/3gs this timeout fires immediately if less than 500ms.                   setTimeout( function (){                        // To avoid failing on return to MobileSafari, ensure freshness!                         if  (+ new  Date - clickedAt < 2000){                             window.location = fail;                         }                   }, 500);                   };           }           $( ‘.icon-download, .btn-download‘ )[0].onclick = applink(appstore);

如何用js檢測手機是否安裝某個app