getElSize(id) { //得到元素的size    return new Promise((res, rej) => {          uni.createSelectorQuery().select('#' + id).fields({               size: true,               scrollOffset: true           }, (data) => {                  res(data);           }).exec();    });},

 

// 异步调用async tapTab(index) { //点击tab-bar	if (this.tabIndex === index) {		return false;	} else {		let tabBar = await this.getElSize("tab-bar"),		console.log(tabBar) } },