function topHeight() {
  const windowInfo = wx.getWindowInfo ? wx.getWindowInfo() : wx.getSystemInfoSync();
  const statusHeight = windowInfo.statusBarHeight || 24;
  let menuBottom = 0;
  try {
    const menu = wx.getMenuButtonBoundingClientRect();
    menuBottom = menu && menu.bottom ? menu.bottom : 0;
  } catch (_) {
    // Some development environments do not expose the menu geometry.
  }
  return Math.ceil(Math.max(menuBottom, statusHeight + 44) + 12);
}

Component({
  data: { height: 100 },
  lifetimes: {
    attached() {
      this.setData({ height: topHeight() });
    },
  },
});