react微信tab切换title不变

setDocumentTitle (title) {
    let $body = document.body;
    document.title = title;
    let $iframe = createDom('<iframe src="/favicon.ico"></iframe>');
    $iframe.addEventListener('load', load);
    $body.appendChild($iframe);

    function load(){
        setTimeout(function() {
            $iframe.removeEventListener('load', load);
            $body.removeChild($iframe);
        }, 0);
    }

    function createDom(htmlStr){
        let tmp = document.createElement('div');
        tmp.innerHTML = htmlStr;
        let children = tmp.childNodes;
        for (let i = 0; i < children.length; i++) {
            if (children[i].nodeType ===1 ) {
                return children[i];
            }
        }
        return;
    }
}

if (this.state.Tab) {
    document.title = '我的';
} else {
    document.title = '你的';
}