//获取宽度，设置高度等于宽度
var query = wx.createSelectorQuery().in(this);
var that = this;
query.select('.chooseImgItem').boundingClientRect(function (rect) {
console.log(rect);
that.setData({
'objHeight': rect.width + 'px'
})
// console.log(that.data.objHeight);
}).exec();
获取元素样式
如果是在自定义组件里面获取的话，需要var query = wx.createSelectorQuery().in(this);
如果是在页面里面获取的话，var query = wx.createSelectorQuery();
