我正在尝试将一个函数传递给生成menu
的孩子想想我早点陷入困境，因为该示例似乎有一个父母和一个孩子，而我的中间有一个HOC：
var comparator;
const GenericIsUserLoggedInLink = React.memo(({ isHomeButton, isLoggedIn, logOutUser, route, anchorText, mobile, name, selected, handleItemClick }) => {
comparator = (prevProps, nextProps) => {
if (prevProps.isHomeButton !== nextProps.setProps.isHomeButton) {
return true;
}
if (prevProps.isLoggedIn !== nextProps.setProps.isLoggedIn) {
return true;
}
if (prevProps.mobile !== nextProps.setProps.mobile) {
return true;
}
if (prevProps.selected !== nextProps.setProps.selected) {
return true;
}
return false;
}
function currentNav(route, name, selected, anchorText, handleItemClick) {
const navItems = ['home', 'profile', 'dashboard'];
return (
<>
<Link href={route}>
{navItems.map(currentNavItem => (
<Menu.Item
key={currentNavItem}
name={name}
active={currentNavItem === selected ? true : false}
onClick={() => handleItemClick(currentNavItem)}>
{anchorText}
</Menu.Item>
))}
</Link>
</>
);
}
if (isHomeButton) {
return currentNav(route, name, selected, anchorText, handleItemClick)
}
if (isLoggedIn) {
if (anchorText === undefined) {
return <Link href="/"><a onClick={() => logOutUser()}>Log out!</a></Link>
}
else if (mobile) {
return currentNav(route, name, selected, anchorText, handleItemClick)
}
else if (!(mobile)) {
return currentNav(route, name, selected, anchorText, handleItemClick)
}
else if (anchorText) {
return <Link href={route}><a>{anchorText}</a></Link>
}
} else {
if (route === "/login") {
return <Link href="/login"><a>Log in!</a></Link>
}
return null
}
}, comparator);
class DesktopContainer extends Component {
state = {activeItem: 'home'}
hideFixedMenu = () => this.setState({ fixed: false })
showFixedMenu = () => this.setState({ fixed: true })
handleItemClick = (activeItem) => this.setState({ activeItem })
logOutUser = () => {
const { logOutUser } = this.props
logOutUser()
}
render() {
const { GenericHeadingComponent, children, getWidth, isLoggedIn, logOutUser } = this.props
const { fixed, activeItem } = this.state
return (
<Responsive getWidth={getWidth} minWidth={Responsive.onlyTablet.minWidth}>
<Visibility
once={false}
onBottomPassed={this.showFixedMenu}
onBottomPassedReverse={this.hideFixedMenu}
>
<Segment
inverted
textAlign='center'
style={{ minHeight: 700, padding: '1em 0em' }}
vertical
>
<Menu
fixed={fixed ? 'top' : null}
inverted={!fixed}
pointing={!fixed}
secondary={!fixed}
size='large'
>
<Container>
<GenericIsUserLoggedInLink
isHomeButton={true}
route="/"
name='home'
selected={activeItem}
handleItemClick={this.handleItemClick}
mobile={false}
/>
<GenericIsUserLoggedInLink
isLoggedIn={isLoggedIn}
route="/profile"
anchorText="Profile"
name='profile'
selected={activeItem}
handleItemClick={this.handleItemClick}
mobile={false}
/>
<GenericIsUserLoggedInLink
isLoggedIn={isLoggedIn}
route="/dashboard"
anchorText="Dashboard"
name='dashboard'
selected={activeItem}
handleItemClick={this.handleItemClick}
mobile={false}
/>
<Menu.Item position='right'>
<Button inverted={!fixed}>
<GenericIsUserLoggedInLink
route="/login"
isLoggedIn={isLoggedIn}
logOutUser={logOutUser}
/>
</Button>
<Button inverted={!fixed} primary={fixed} style={{ marginLeft: '0.5em' }}>
<Link href="/register">
<a>Register</a>
</Link>
</Button>
</Menu.Item>
</Container>
</Menu>
<GenericHeadingComponent />
</Segment>
</Visibility>
{children}
</Responsive>
)
}
}
DesktopContainer.propTypes = {
children: PropTypes.node,
}
class MobileContainer extends Component {
state = { activeItem: 'home' }
handleSidebarHide = () => this.setState({ sidebarOpened: false })
handleToggle = () => this.setState({ sidebarOpened: true })
handleItemClick = (activeItem) => this.setState({ activeItem })
logOutUser = () => {
const { logOutUser } = this.props
logOutUser()
}
render() {
const { GenericHeadingComponent, children, getWidth, isLoggedIn, logOutUser, mobile } = this.props
const { sidebarOpened, activeItem } = this.state
return (
<Responsive
as={Sidebar.Pushable}
getWidth={getWidth}
maxWidth={Responsive.onlyMobile.maxWidth}
>
<Sidebar
as={Menu}
animation='push'
inverted
onHide={this.handleSidebarHide}
vertical
visible={sidebarOpened}
>
<GenericIsUserLoggedInLink
isHomeButton={true}
route="/"
name='home'
anchorText="Home"
selected={activeItem}
handleItemClick={this.handleItemClick}
mobile={true}
/>
<GenericIsUserLoggedInLink
isLoggedIn={isLoggedIn}
route="/profile"
anchorText="Profile"
name='profile'
selected={activeItem}
handleItemClick={this.handleItemClick}
mobile={true}
/>
<GenericIsUserLoggedInLink
isLoggedIn={isLoggedIn}
route="/dashboard"
anchorText="Dashboard"
name='dashboard'
selected={activeItem}
handleItemClick={this.handleItemClick}
mobile={true}
/>
<Menu.Item>
<GenericIsUserLoggedInLink
route="/login"
isLoggedIn={isLoggedIn}
logOutUser={logOutUser}
/>
</Menu.Item>
<Menu.Item >
<Link href="/register">
<a>Register</a>
</Link>
</Menu.Item>
</Sidebar>
<Sidebar.Pusher dimmed={sidebarOpened}>
<Segment
inverted
textAlign='center'
style={{ minHeight: 350, padding: '1em 0em' }}
vertical
>
<Container>
<Menu inverted pointing secondary size='large'>
<Menu.Item onClick={this.handleToggle}>
<Icon name='sidebar' />
</Menu.Item>
</Menu>
</Container>
<GenericHeadingComponent mobile={mobile} />
</Segment>
{children}
</Sidebar.Pusher>
</Responsive>
)
}
}
MobileContainer.propTypes = {
children: PropTypes.node,
}
此错误是由我的<DesktopContainer/> 和 <MobileContainer/>组件引起的。
这些是错误：
index.js:1 The above error occurred in the <Link> component:
in Link
in Unknown (created by MobileContainer)
in div (created by Menu)
in Menu (created by Sidebar)
in RefFindNode (created by Ref)
in Ref (created by Sidebar)
in Sidebar (created by MobileContainer)
in div (created by SidebarPushable)
in SidebarPushable (created by Responsive)
in Responsive (created by MobileContainer)
in MobileContainer (created by LayoutComponent)
in LayoutComponent (created by Connect(LayoutComponent))
in Connect(LayoutComponent) (created by HomepageLayout)
in HomepageLayout (created by Connect(HomepageLayout))
in Connect(HomepageLayout) (created by Home)
in Home (created by Connect(Home))
in Connect(Home) (created by MyApp)
in PersistGate (created by MyApp)
in Provider (created by MyApp)
in MyApp (created by AppWithRedux)
in AppWithRedux
in Suspense (created by AppContainer)
in Container (created by AppContainer)
in AppContainer
VM451 main.js:12445 The above error occurred in the <Link> component:
in Link
in Unknown (created by DesktopContainer)
in div (created by Container)
in Container (created by DesktopContainer)
in div (created by Menu)
in Menu (created by DesktopContainer)
in div (created by Segment)
in Segment (created by DesktopContainer)
in div (created by Visibility)
in RefFindNode (created by Ref)
in Ref (created by Visibility)
in Visibility (created by DesktopContainer)
in div (created by Responsive)
in Responsive (created by DesktopContainer)
in DesktopContainer (created by LayoutComponent)
in LayoutComponent (created by Connect(LayoutComponent))
in Connect(LayoutComponent) (created by HomepageLayout)
in HomepageLayout (created by Connect(HomepageLayout))
in Connect(HomepageLayout) (created by Home)
in Home (created by Connect(Home))
in Connect(Home) (created by MyApp)
in PersistGate (created by MyApp)
in Provider (created by MyApp)
in MyApp (created by AppWithRedux)
in AppWithRedux
in Suspense (created by AppContainer)
in Container (created by AppContainer)
in AppContainer
VM453 dll_397dc449097af0b4e992.js:26942 Uncaught Invariant Violation: React.Children.only expected to receive a single React element child.
at http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:26942:26
at Object.onlyChild [as only] (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:26945:5)
at Link.render (http://localhost:8016/_next/static/development/pages/index.js?ts=1572206599026:25504:35)
at finishClassComponent (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:17380:31)
at updateClassComponent (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:17335:24)
at beginWork$1 (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:18846:16)
at HTMLUnknownElement.callCallback (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:688:14)
at Object.invokeGuardedCallbackDev (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:738:16)
at invokeGuardedCallback (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:795:31)
at beginWork$$1 (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:23558:7)
at performUnitOfWork (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:22549:12)
at workLoopSync (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:22526:22)
at renderRoot (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:22219:11)
at scheduleUpdateOnFiber (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:21760:22)
at scheduleRootUpdate (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:24660:3)
at updateContainerAtExpirationTime (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:24688:10)
at updateContainer (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:24777:10)
at http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:25304:7
at unbatchedUpdates (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:22028:12)
at legacyRenderSubtreeIntoContainer (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:25303:5)
at Object.hydrate (http://localhost:8016/_next/static/development/dll/dll_397dc449097af0b4e992.js?ts=1572206599026:25370:12)
at renderReactElement (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:9362:26)
at _callee4$ (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:9494:13)
at tryCatch (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:698:40)
at Generator.invoke [as _invoke] (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:924:22)
at Generator.prototype.<computed> [as next] (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:750:21)
at asyncGeneratorStep (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:226:24)
at _next (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:248:9)
at http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:255:7
at new Promise (<anonymous>)
at new F (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:2352:28)
at http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:244:12
at _doRender (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:9508:20)
at doRender (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:9437:20)
at _callee2$ (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:9247:20)
at tryCatch (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:698:40)
at Generator.invoke [as _invoke] (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:924:22)
at Generator.prototype.<computed> [as next] (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:750:21)
at asyncGeneratorStep (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:226:24)
at _next (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:248:9)
at http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:255:7
at new Promise (<anonymous>)
at new F (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:2352:28)
at http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:244:12
at _render (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:9268:18)
at render (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:9219:18)
at _callee$ (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:9200:13)
at tryCatch (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:698:40)
at Generator.invoke [as _invoke] (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:924:22)
at Generator.prototype.<computed> [as next] (http://localhost:8016/_next/static/runtime/main.js?ts=1572206599026:750:21)
有人能发现我可以包裹<></>来消除该错误的地方吗？
答案 0 :(得分：2)
Link期望有one个孩子，如果提供了多个孩子，则会抛出错误。
您可以使用a标签包裹多个孩子：
<Link href={route}>
<a>
{navItems.map(currentNavItem => (
<Menu.Item
key={currentNavItem}
name={name}
active={currentNavItem === selected ? true : false}
onClick={() => handleItemClick(currentNavItem)}>
{anchorText}
</Menu.Item>
))}
</a>
</Link>
答案 1 :(得分：1)
if 在 next.js 中出现错误
<Link href="/"><a> Home </a></Link>
试试下面的方法对我有用
<Link href="/">
<a> Home </a>
</Link>