微信小程序底部的tabbar高度

const systemInfo = wx.getSystemInfoSync();
const { screenHeight, windowHeight, statusBarHeight } = systemInfo;

// 获取胶囊按钮信息
const menuButtonInfo = wx.getMenuButtonBoundingClientRect();
// 计算导航栏高度（胶囊按钮top + 胶囊高度 + 下边距7px）
const navigationBarHeight = menuButtonInfo.top + menuButtonInfo.height;
// 最终计算 tabBar 高度
const tabBarHeight = screenHeight - windowHeight - statusBarHeight - navigationBarHeight;
console.log('TabBar Height:', tabBarHeight);