如何将状态从子组件传递到应用程序组件

Question

I have 2 components which both have sub components, In one of the components if the sub component is clicked I want to transfer that to the app component so it renders a totally new Component for me

I want to use ```use state`` but where am I meant to start it. I will show code of what I started but blocked on how to continue

app.jsx

import React, { useState, useEffect } from 'react';
import './App.css';
import SignIn from './components/sign-in/SignIn';
import SignUpOptions from './components/sign-in/sign-up-select-business-option';

const [signUp, setSignUp] = useState(false);

const App = () => {
  if (signUp) {
    return <SignUpOptions/>
  }
    return <SignIn/>

};

export default App;

signin.jsx

const SignIn = () => (
<div style={{display:'flex'}}>
  <div style={{flex:2}}>
    <ImageDiv bg={signin} src = {signin} alt="logo">
      <LogoDiv src={logo} alt="logo" />
    </ImageDiv>
  </div>
  <FormDiv>
    <Input style={{marginTop: `${44  }px`}} placeholder="Username" />
    <Input style={{marginTop: `${44  }px`}} placeholder="Password" />
    <Button style={{marginTop: `${45  }px`}}>Sign in</Button>
    <ForgotPassword>Forgot username or password</ForgotPassword>
    <SignUpParagraph>Don’t have an account? Sign up</SignUpParagraph>
  </FormDiv> 
</div>
)

export default SignIn;

So in signin if I press i want the in app.jsx to load

Answer 1

Since you are new , I won't give you a duplicate link

app.jsx

const [signUp, setSignUp] = useState(false);

const App = () => {
  if (signUp) {
    return <SignUpOptions/>
  }
    return <SignIn setSignUp={setSignUp}/>

};

signin.jsx

const SignIn = (props) => (
<div style={{display:'flex'}}>
  <div style={{flex:2}}>
    <ImageDiv bg={signin} src = {signin} alt="logo">
      <LogoDiv src={logo} alt="logo" />
    </ImageDiv>
  </div>
 <FormDiv>
    <Input style={{marginTop: `${44  }px`}} placeholder="Username" />
    <Input style={{marginTop: `${44  }px`}} placeholder="Password" />
    <Button style={{marginTop: `${45  }px`}}>Sign in</Button>
    <ForgotPassword>Forgot username or password</ForgotPassword>
    <SignUpParagraph setSignUp={props.setSignUp}>Don’t have an account? Sign up</SignUpParagraph>
  </FormDiv> 

SignUpParagraph.js

const SignUpParagraph = (props) => (
<div onClick={()=>props.setSignUp(true)}>//anything you have in here </div>

Comment if it worked

Answer 2

Although you already found an answer I can still give you another method on your way.

With React Context you could make functions in you index/app.js and call them with you child component. This is an lightweight alternative which works very well, aswell with hooks.

Greetings