监听localStorage值

function dispatchEventStroage () {
    const signSetItem = localStorage.setItem;
    localStorage.setItem = function (key, val) {
        let setEvent = new Event('setItemEvent')
        setEvent.key = key
        setEvent.newValue = val
        window.dispatchEvent(setEvent)
        signSetItem.apply(this, arguments)
    }
};

dispatchEventStroage();

window.addEventListener('setItemEvent', function (e) {
 console.log('change信息：',e);
})