判断是否呼起某个app

   function isAppInstall(callback) {
        console.log('in isAppInstall')
        let startTime = +new Date()
        let client = getClient()
        let isAndroid = getPlatform() === 'android'
        //直接打开
        openSchema('weixin://')

        //通过是否成功打开判断是否安装
        if (isAndroid) {
            //android 打开app后，setTimeout中的执行栈被停掉了
            setTimeout(function() {
                let delta = +new Date() - startTime
                if (delta < 850) {
                    //没有安装
                    callback('no')
                } else {
                    //安装
                    callback('yes')
                }
            }, 800)
        } else {
            //如果是safari，
            //ios打开app后，setTimeout会继续执行，用页面可见性判断
            let hidden, state, visibilityChange
            if (typeof document.hidden !== 'undefined') {
                hidden = 'hidden'
                visibilityChange = 'visibilitychange'
                state = 'visibilityState'
            } else if (typeof document.mozHidden !== 'undefined') {
                hidden = 'mozHidden'
                visibilityChange = 'mozvisibilitychange'
                state = 'mozVisibilityState'
            } else if (typeof document.msHidden !== 'undefined') {
                hidden = 'msHidden'
                visibilityChange = 'msvisibilitychange'
                state = 'msVisibilityState'
            } else if (typeof document.webkitHidden !== 'undefined') {
                hidden = 'webkitHidden'
                visibilityChange = 'webkitvisibilitychange'
                state = 'webkitVisibilityState'
            }
            if (visibilityChange) {
                //设置一个超时,如果在2s内页面可见性没变化，可以判断是没有安装
                //safafi中,会有一个确认弹框,没法判断
                //但是如果用户在2秒之内打开客户端然后又返回h5页面，是会呼起appstore的，暂时解决不了这个问题
                let timeoutId = setTimeout(function() {
                    callback('no')
                    document.removeEventListener(visibilityChange, fn)
                }, 2000)
                let fn = function(data) {
                    //如果能打开其余的app,会触发hidden
                    if (document[state] === hidden || data.hidden) {
                        callback('yes')
                        clearTimeout(timeoutId)
                    }
                    document.removeEventListener(visibilityChange, fn)
                }
                if (client === 'qzone') {
                    window.mqq &&
                        mqq.addEventListener('qbrowserVisibilityChange', function(da) {
                            fn(da)
                        })
                } else {
                    document.addEventListener(visibilityChange, fn, false)
                }
            } else {
                callback('unknow')
            }
        }
    }

function getClient() {
    let ua = navigator.userAgent
    let isWX = ua.match(/MicroMessenger\/([\d\.]+)/), //微信
        isQQ = ua.match(/QQ\/([\d\.]+)/) || ua.match('_SQ_'), //手Q
        isQzone = ua.match('Qzone/') || ua.match('_QZ_'), //手空
        isQQMusic = /QQMUSIC\/(\d[\.\d]*)/i.test(ua), //qq音乐
        isQQBrowser = ua.match('MQQBrowser') && ua.indexOf('TBS') === -1, //qq浏览器
        isFM = ua.match('_FM_'), //企鹅FM
        isTencentVideo = ua.match('QQLiveBrowser'), //腾讯视频
        isQQNews = ua.match('qqnews'), //腾讯新闻
        isQQSecure = ua.match('Secure'), // 安全管家
        isWiFiManager = /wifimanager/i.test(ua), // wifi管家
        isWS = ua.match('_WEISHI_'), //微视
        isYYB = /\/qqdownloader\/(\d+)(?:\/(appdetail|external|sdk))?/.test(ua), //应用宝
        isWeiyun = ua.match(/Weiyun\/(\d\.)+/) // 微云

    let rs = 'normal'

    if (isQQ) {
        rs = 'qq'
    } else if (isQzone) {
        rs = 'qzone'
    } else if (isWX) {
        rs = 'wx'
    } else if (isQQMusic) {
        rs = 'qqmusic'
    } else if (isFM) {
        rs = 'fm'
    } else if (isWS) {
        rs = 'ws'
    } else if (isYYB) {
        rs = 'yyb'
    } else if (isQQBrowser) {
        rs = 'QQBrowser'
    } else if (isQQSecure) {
        rs = 'QQSecure'
    } else if (isWiFiManager) {
        rs = 'QQSecure' // 手机管家和wifi管家用的是同一套jsBridge
    } else if (isQQNews) {
        rs = 'QQNews'
    } else if (isWeiyun) {
        rs = 'Weiyun'
    } else if (isTencentVideo) {
        rs = 'TencentVideo'
    }
    return rs
}

function getPlatform() {
    let ua = navigator.userAgent
    let ipad = ua.match(/(iPad).*OS\s([\d_]+)/),
        isIphone = !ipad && ua.match(/(iPhone\sOS)\s([\d_]+)/),
        isAndroid = ua.match(/Android/)
    if (isIphone || ipad) {
        return 'ios'
    } else if (isAndroid) {
        return 'android'
    } else {
        return 'pc'
    }
}