<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> </body> <script> var ua = navigator.userAgent.toLowerCase(); alert(ua) if (ua.match(/mqqbrowser/i) == "mqqbrowser") { // $(".shadow-img").fadeIn(500) alert("我真的是QQ") } </script> </html>