let isMac = /macintosh|mac os x/i.test(navigator.userAgent); //苹果
/windows|win32/i.test(navigator.userAgent);//Windows
/linux/i.test(navigator.userAgent);//Linux
let isMac = /macintosh|mac os x/i.test(navigator.userAgent); //苹果
/windows|win32/i.test(navigator.userAgent);//Windows
/linux/i.test(navigator.userAgent);//Linux