此路线:

FlowRouter.route('/', {
  action() {
    BlazeLayout.render('mainLayout', { content: 'mainLayout' });
  },
});

无效，因为您正在将mainLayout组件插入自身-嵌套的content助手是问题所在.相反，您应该在content中渲染另一个组件:

is not going to work because you are inserting the mainLayout component into itself - the nested content helper is the issue. Instead, you should be rendering a different component into content:

BlazeLayout.render('mainLayout', { content: 'home' }); // or whatever component should be at "/"