code: function createPage(id) {
    return new Promise((resolve, reject) => {
      const pageId = id.substring(0, id.lastIndexOf("_"));
      let Class;
      const pageRouterConfig = this.config.router[pageId];
      if (pageRouterConfig) {
        const component = this.config.router[pageId].component;
        if (component && component.then) {
          component.then((Page) => {
            if (Page) {
              Class = Page.default;
              // 可以进行实例化，一般都是inline模式
              if (Class) {
                resolve(newInstance.call(this, {Class, id, pageId}));
              } else {
                reject();
              }
            } else {
              reject();
            }
          }).catch((error) => {
            reject(error);
          });
        } else {
          // 使用缺省的Page实例
          resolve(newInstance.call(this, {Page, id, pageId}));
          //throw `没有${pageId}的页面`;
        }
      } else {
        resolve(newInstance.call(this, {Page, id, pageId}));
      }
    });
  }
docs: 通过ID创建Page对象
  @access private
  @param {string} id
  @return {Promise}