设置标题：
wx.setNavigationBarTitle({
title: '页面标题',
})
获取标题：
const pages = getCurrentPages();
const pageUrl = pages[pages.length - 1].route;
let pageWindow = {};
const wxPage = __wxConfig.page;
if(wxPage && Object.keys(wxPage).length) {
for(const key in wxPage) {
if(key.includes(pageUrl)) {
pageWindow = wxPage[key].window || {};
break;
}
}
}
const title = pageWindow.navigationBarTitleText || '';
console.log(title);