javascript - 如何从类组件更新功能组件的状态，以便在 react 中显示 map 中的项目

Question

我在 Gatsby JS 中有一个 StoreDetails 功能组件，它有条件地从 graphQL 中的 map 渲染产品，该 map 使用 UseState Hook 与状态值匹配。我有一个类组件下拉菜单，当前手动填充了 sku'id，这些 sku'id 与状态和 map 条件语句中显示的条件相匹配。我希望下拉列表更改功能组件的状态，以便在下拉列表中选择正确的产品时显示该产品。我正在尝试将状态函数作为 Prop 传递，但我遇到了重新渲染问题，完全卡在这里。

关键在这一行{value.skuId === sku.skuId ?当选项下拉列表仍在 map 内时，如何根据它进行更改

提前致谢

这是我到目前为止的代码

import React, {useState} from 'react';
import Layout from "../components/layout"
import styled from 'styled-components';
import {loadStripe} from '@stripe/stripe-js';
// import Alert from '../components/Alert';
import { navigate } from "gatsby";
import Img from "gatsby-image"





const StoreHero = styled.section`
    width:1280px;
    margin:0 auto;
`

class Alert extends React.Component{
    constructor(props){
        super(props);

        //console.log(props);

        this.state = {test:"test",hello:"hello1",hash:props.hash}
    }
    render(){
        const { test, hello, hash } = this.state

        //console.log(hash);

        return(
            <div>{hash}</div>
        )
    }
}


class ShowItem extends React.Component {
  constructor(props) {
    super(props);
    this.state = {value: 'coconut'};

    this.handleChange = this.handleChange.bind(this);
  }

  handleChange(event) {
    this.setState({value: event.target.value});
    console.log(event.target.value);

    // Right here is where I want to change the state of the value variable below so
    // that the correct product is shown based on the dropdown sku selection

  }


  render() {


    return (

          <select value={this.state.value} onChange={this.handleChange}>
            <option value="sku_HAD1kUsbV3GpgW">sku_HAD1kUsbV3GpgW</option>
            <option value="sku_HACMgLjJBZFR7A">sku_HACMgLjJBZFR7A</option>
          </select>


    );
  }
}

class Product extends React.Component{

    constructor(props) {
        super(props);

        this.state = {
          stripe: null
        };

                this.loadStripeLib = this.loadStripeLib.bind(this);
                this.handleSubmit = this.handleSubmit.bind(this);
      }

      componentDidMount() {
        this.loadStripeLib()
      }

      async loadStripeLib() {
        try {
          const stripe = await loadStripe('pk_test_random');
          this.setState({ stripe });
        } catch {
          // do nothing
        }
      }

      handleSubmit(sku, productId){
          return event => {
              event.preventDefault();
              this.state.stripe.redirectToCheckout({
                items: [{sku, quantity: 1}],
                successUrl: `http://localhost:8000/store/${productId}#success`,
                cancelUrl: `http://localhost:8000/store/${productId}#cancelled`,
              }).then(function (result) {
                // Display result.error.message to your customer
                console.error(result);
              });
          }
            }


      render(){
                    const { id, currency, price, name, productId } = this.props

                    const priceFloat = (price / 100).toFixed(2)
                    const formattedPrice = Intl.NumberFormat('en-US', {
                    style: 'currency',
                    currency,
                    }).format(priceFloat)

          return(
              <form onSubmit={this.handleSubmit(id, productId)}>
                                <h2>
                                    {name} ({formattedPrice})
                                </h2>
                <button type="submit">Buy Now</button>

              </form>
          )
      }

}

const StoreDetails = ({data, location}) =>{

  const [value, setValue] = useState({
    skuId: "sku_HAD1kUsbV3GpgW"
  });



    //console.log(value);



    return(
        <Layout>
            <StoreHero>
                        <Alert test="test" hello="hello" hash={location.hash}/>

            {/* <ShowItem props={data}/> */}                                    

              {data.allDatoCmsStore.edges.map(({ node: sku }) => (
                <>
                {value.skuId === sku.skuId ?
                  <>
                    <ShowItem setValue={setValue}/>
                    <Product
                      key={sku.id}
                      id={sku.skuId}
                      productId={sku.productId}
                      currency="cad"
                      price={sku.price}
                      name={sku.title}
                    />
                    <Img fixed={sku.image.fixed}/>
                  </>
                :
                  null
                }

                </>
              ))}

            </StoreHero>
        </Layout>
    )

}

export default StoreDetails

export const query = graphql`
  query StoreDeatailsQuery($slug: String!)  {
    allDatoCmsStore(filter: {productId: {eq: $slug}}) {
      edges {
        node {
          price
          productId
          skuId
          title
          id
          image{
            fixed{
              ...GatsbyDatoCmsFixed
            }
          }
        }
      }
    }
    allStripeSku {
        edges {
          node {
            id
            currency
            price
            attributes {
              name
            }
            image
            localFiles {
              childImageSharp {
                fixed(width: 125) {
                  ...GatsbyImageSharpFixed
                }
              }
            }
          }
        }
      }
  }
`

Answer 1

看起来我把它弄得太复杂了，我还有更多事情要做，但是将其更改为这个对我来说解决了

const StoreDetails = ({data, location}) =>{

  const [value, setValue] = useState({
    skuId: "sku_HAD1kUsbV3GpgW"
  });


  const run = (event) =>{
    console.log(event);
    setValue({skuId:event})
  }


    return(
        <Layout>
            <StoreHero>
                        <Alert test="test" hello="hello" hash={location.hash}/>

            {/* <ShowItem props={data}/> */}                                    

              {data.allDatoCmsStore.edges.map(({ node: sku }) => (
                <>
                {value.skuId === sku.skuId ?
                  <>
                  <select onChange={(event) => run(event.target.value)}>
                    <option value="sku_HAD1kUsbV3GpgW">sku_HAD1kUsbV3GpgW</option>
                    <option value="sku_HACMgLjJBZFR7A">sku_HACMgLjJBZFR7A</option>
                  </select>
                    {/* <ShowItem setValue={setValue}/> */}
                    <Product
                      key={sku.id}
                      id={sku.skuId}
                      productId={sku.productId}
                      currency="cad"
                      price={sku.price}
                      name={sku.title}
                    />
                    <Img fixed={sku.image.fixed}/>
                  </>
                :
                  null
                }

                </>
              ))}

            </StoreHero>
        </Layout>
    )

}