String appId = Constants.APP_ID; // 填应用AppId
IWXAPI api = WXAPIFactory.createWXAPI(mContext, appId);

WXLaunchMiniProgram.Req req = new WXLaunchMiniProgram.Req();
req.userName = smallId; // 填小程序原始id
req.miniprogramType = BuildConfig.IS_DEVELOPE ? WXLaunchMiniProgram.Req.MINIPROGRAM_TYPE_PREVIEW :
        WXLaunchMiniProgram.Req.MINIPTOGRAM_TYPE_RELEASE;// 可选打开 开发版，体验版和正式版
req.path = path;
api.sendReq(req);