判断是ios还是Android

	const ua = navigator.userAgent.toLowerCase()
	let isiOS = false
	if(!!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/)){//是ios
		isiOS = true
	}else{
		isiOS = false
	}

判断是微信还是钉钉

	const ua = navigator.userAgent.toLowerCase()
	let isWeiXin = false
	let isDingTalk = false
	if(ua.match(/DingTalk/i)=="dingtalk"){//用钉钉打开
		isDingTalk = true
	}else if(ua.match(/MicroMessenger/i)=="micromessenger"){//用微信打开
		isWeiXin = true
	}else{//用其他浏览器打开
	
	}