获取小程序的appid,获取小程序的当前版本号，直接调用wx.getAccountInfoSync()，直接上代码：

微信官方文档 https://developers.weixin.qq.com/miniprogram/dev/api/open-api/account-info/wx.getAccountInfoSync.html

let accountInfo = wx.getAccountInfoSync(); 
let appid = accountInfo.miniProgram.appId; // "wxfb6368d158c85cb7"小程序appid
let envVersion = accountInfo.miniProgram.envVersion; // "develop"开发版
let version = accountInfo.miniProgram.version; // 1.0.0 小程序版本号