单击父路由时保持子路由不变

const routes = [
  {
    path: '/parent',
    component: ParentComponent,
    children: [
      {
        path: 'child',
        component: ChildComponent
      }
    ]
  }
]

router.beforeEach((to, from, next) => {
  if (to.path.startsWith('/parent')) {
    // 如果目标路由是父路由，则重定向到子路由
    next('/parent/child');
  } else {
    next();
  }
});

class ParentComponent extends React.Component {
  render() {
    return (
      <div>
        <h1>Parent Component</h1>
        {this.props.location.pathname === '/parent' && <ChildComponent />}
      </div>
    );
  }
}