APP内嵌H5页面，H5页面向APP发送消息

//ios
window.webkit.messageHandlers.qrcode.postMessage(url);

//android
client.qrcode(this.imgUrl);

    postApp: function (type, cb) {
        //客户端回调的方法与type保持一致
        // console.log('postApp',type,cb)
        try {
            if (uni.getSystemInfoSync().platform == "android") {
                AndroidJs.postApp(type);
            } else {
                window.webkit.messageHandlers.postApp.postMessage(type);
            }
        } catch (err) {
            //TODO handle the exception
            cb && cb(err);
        }
    }