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[英]React Hook "React.useState" is called in function "form" that is neither a React function component nor a custom React Hook function
[英]Trying to Create a react Component but getting React Hook "React.useState" cannot be called at the top level."
我正在嘗試向我的 React 組件添加一堆模式,但我不斷收到錯誤“無法在頂層調用“React.useState”。 這段代碼最初在我的 App.js 文件中,它可以運行,但我想通過將其制成組件來使其更整潔。
const[showTotModal, setTotShowModal] = React.useState(false)
const openTotModal = () => {
setTotShowModal(prev => !prev);
};
const[showCasModal, setCasShowModal] = React.useState(false)
const openCasModal = () => {
setCasShowModal(prev => !prev);
};
const[showGraModal, setGraShowModal] = React.useState(false)
const openGraModal = () => {
setGraShowModal(prev => !prev);
};
const[showKikModal, setKikShowModal] = React.useState(false)
const openKikModal = () => {
setKikShowModal(prev => !prev);
};
const[showSpiModal, setSpiShowModal] = React.useState(false)
const openSpiModal = () => {
setSpiShowModal(prev => !prev);
};
const[showHowModal, setHowShowModal] = React.useState(false)
const openHowModal = () => {
setHowShowModal(prev => !prev);
};
class GhibliModal extends Component{
render(){
return(
<Container>
<Button onClick={openTotModal}> <img src={tot} alt="tot" height='300' /> </Button>
<Button onClick={openCasModal}> <img src={cas} alt="cas" height='300' /> </Button>
<Button onClick={openGraModal}> <img src={gra} alt="gra" height='300' /> </Button>
<Button onClick={openKikModal}> <img src={kik} alt="gra" height='300' /> </Button>
<Button onClick={openSpiModal}> <img src={spi} alt="gra" height='300' /> </Button>
<Button onClick={openHowModal}> <img src={how} alt="gra" height='300' /> </Button>
<TotModal showModal={showTotModal} setShowModal={setTotShowModal}/>
<CasModal showModal={showCasModal} setShowModal={setCasShowModal}/>
<GraModal showModal={showGraModal} setShowModal={setGraShowModal}/>
<KikModal showModal={showKikModal} setShowModal={setKikShowModal}/>
<SpiModal showModal={showSpiModal} setShowModal={setSpiShowModal}/>
<HowModal showModal={showHowModal} setShowModal={setHowShowModal}/>
</Container>
)
}
}
export default GhibliModal
First Thing Hooks 僅適用於功能組件,您正在創建 class 組件並在其上放置掛鈎 這是相同的代碼,我剛剛將 class 組件轉換為箭頭 ZC1C425268E68385D1AB5074C17A94F4 組件並將掛鈎放置在組件內部
const GhibliModal = () =>{
const[showTotModal, setTotShowModal] = React.useState(false)
const[showHowModal, setHowShowModal] = React.useState(false)
const[showCasModal, setCasShowModal] = React.useState(false)
const[showGraModal, setGraShowModal] = React.useState(false)
const[showKikModal, setKikShowModal] = React.useState(false)
const[showSpiModal, setSpiShowModal] = React.useState(false)
const openTotModal = () => {
setTotShowModal(prev => !prev);
};
const openCasModal = () => {
setCasShowModal(prev => !prev);
};
const openGraModal = () => {
setGraShowModal(prev => !prev);
};
const openKikModal = () => {
setKikShowModal(prev => !prev);
};
const openSpiModal = () => {
setSpiShowModal(prev => !prev);
};
const openHowModal = () => {
setHowShowModal(prev => !prev);
};
return(
<Container>
<Button onClick={openTotModal}> <img src={tot} alt="tot" height='300' /> </Button>
<Button onClick={openCasModal}> <img src={cas} alt="cas" height='300' /> </Button>
<Button onClick={openGraModal}> <img src={gra} alt="gra" height='300' /> </Button>
<Button onClick={openKikModal}> <img src={kik} alt="gra" height='300' /> </Button>
<Button onClick={openSpiModal}> <img src={spi} alt="gra" height='300' /> </Button>
<Button onClick={openHowModal}> <img src={how} alt="gra" height='300' /> </Button>
<TotModal showModal={showTotModal} setShowModal={setTotShowModal}/>
<CasModal showModal={showCasModal} setShowModal={setCasShowModal}/>
<GraModal showModal={showGraModal} setShowModal={setGraShowModal}/>
<KikModal showModal={showKikModal} setShowModal={setKikShowModal}/>
<SpiModal showModal={showSpiModal} setShowModal={setSpiShowModal}/>
<HowModal showModal={showHowModal} setShowModal={setHowShowModal}/>
</Container>
)
}
export default GhibliModal
useState
鈎子是 function 組件的替代品,因為后者沒有 state。
添加構造函數:
constructor(props) {
super(props);
this.state = {tot: false, how: false, cas: false, gra: false, kik:false, spi: false };
}
並將其他方法添加到 class 組件的主體中。
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