reactjs

问题 Consider this basic form fields component with a custom form hook to handle input changes: import React, { useState, useCallback } from 'react'; const useFormInputs = (initialState = {})=> { const [values, setValues] = useState(initialState); const handleChange = useCallback(({ target: { name, value } }) => { setValues(prev => ({ ...prev, [name]: value })); }, []); const resetFields = useCallback(() => setValues(initialState), [initialState]); return [values, handleChange, resetFields]; };

问题 I'm working on a React project with Cloud Firestore. I have successfully fetched data from Firestore. But I could not set state these data to state. How can I set state these data. class App extends Component { constructor(props) { super(props); this.state = { items: [] }; } async componentDidMount() { const items = []; firebase .firestore() .collection("items") .get() .then(function(querySnapshot) { querySnapshot.forEach(function(doc) { items.push(doc.data()); }); }); this.setState({ items:

问题 Consider this basic form fields component with a custom form hook to handle input changes: import React, { useState, useCallback } from 'react'; const useFormInputs = (initialState = {})=> { const [values, setValues] = useState(initialState); const handleChange = useCallback(({ target: { name, value } }) => { setValues(prev => ({ ...prev, [name]: value })); }, []); const resetFields = useCallback(() => setValues(initialState), [initialState]); return [values, handleChange, resetFields]; };

问题 My question is almost the same as this one. In this case, the person has a map of states created in a hard coded way: const App = props => { const [state, changeState] = useState({ name: "", eventTitle: "", details: "", list: "", toggleIndex: "", editName: "", editEventTitle: "", editDetails: "", }); The difference is that I want to create those states dynamically, receiving them from another component. I tried something like this but it obviously did not work: const App = props => { const

问题 Consider this basic form fields component with a custom form hook to handle input changes: import React, { useState, useCallback } from 'react'; const useFormInputs = (initialState = {})=> { const [values, setValues] = useState(initialState); const handleChange = useCallback(({ target: { name, value } }) => { setValues(prev => ({ ...prev, [name]: value })); }, []); const resetFields = useCallback(() => setValues(initialState), [initialState]); return [values, handleChange, resetFields]; };

问题 I'm trying to simulate a hover effect for my component. However, the onMouseEnter / Leave events are not working as expected, right now I'm trying to get it to simply console.log a string to check that its working but nothing is happening. The aim is that I can change its background color on hover; I tried setting this through a CSS class:hover but to no avail. How do I get the OnMouseEnter / onMouseLeave to function properly? here's the code: import React from "react" import ReactDOM from

问题 Question about using images in React! Importing a pic and then using it works: import photo from "../img/profilephoto.jpg" <img src={photo} /> Using props as the source inside a require() works: <img src={require(`../img/${this.props.img}`)} /> But importing an object (with more objects), and then using navigation to get a string, does not work! import text from "../text" // This is the object wich contains more objects <img src={require(`../img/${text.contact.photo}`)} /> Error because "text

问题 Question about using images in React! Importing a pic and then using it works: import photo from "../img/profilephoto.jpg" <img src={photo} /> Using props as the source inside a require() works: <img src={require(`../img/${this.props.img}`)} /> But importing an object (with more objects), and then using navigation to get a string, does not work! import text from "../text" // This is the object wich contains more objects <img src={require(`../img/${text.contact.photo}`)} /> Error because "text

问题 Question about using images in React! Importing a pic and then using it works: import photo from "../img/profilephoto.jpg" <img src={photo} /> Using props as the source inside a require() works: <img src={require(`../img/${this.props.img}`)} /> But importing an object (with more objects), and then using navigation to get a string, does not work! import text from "../text" // This is the object wich contains more objects <img src={require(`../img/${text.contact.photo}`)} /> Error because "text

问题 I am trying to manage a react app with react router and node js server my router in react : <BrowserRouter> <Switch> <PrivateRoute token={token} Component={Payments} exact path="/payments"/> <PrivateRoute token={token} Component={User} exact path="/user"/> <PrivateRoute token={token} Component={User} exact path=""/> <PrivateRoute token={token} Component={User} exact path="/"/> </Switch> <BrowserRouter/> export const PrivateRoute = ({Component, ...rest,token}) => { return ( <Route {...rest}