Question

我目前正在学习react-redux，并且尝试使用从API提取的数组更新全局状态。触发onClick事件时，页面会在设置全局状态之前渲染新组件。当NavLink设置为“＃”时，可以设置状态。在渲染新组件之前，我该如何重新填充状态？

我的主要目的是将获取的数组传递给其他组件以显示获取的信息。

组件

function Selector(props) {
  const [alcoholCategory, setAlcoholCategory] = useState([]);

useEffect(() => {
    props.handleCategorySelection(alcoholCategory);
  });

  function handleImagePress(alc) {
    fetch(`https://www.thecocktaildb.com/api/json/v1/1/filter.php?i=${alc}
    `)
      .then((r) => r.json())
      .then((result) => setAlcoholCategory(result.drinks))
      .then(props.handleCategorySelection(alcoholCategory));
  }
  console.log(alcoholCategory);
  return (
    <div className="selector-div">
      <ul>
        <li>
          <NavLink to="vodka" onClick={() => handleImagePress("Vodka")}>
            <img
              src="https://hips.hearstapps.com/vader-prod.s3.amazonaws.com/1583334281-smirnoff-1583334273.png"
              alt="alcohol-bottle"
              className="selector-bottle-img"
            ></img>
          </NavLink>
          <label>Vodka</label>
        </li>
<li>
          <a href="/rum" onClick={() => handleImagePress("Rum")}>
            <img
              src="https://hips.hearstapps.com/vader-prod.s3.amazonaws.com/1583334281-smirnoff-1583334273.png"
              alt="alcohol-bottle"
              className="selector-bottle-img"
            ></img>
          </a>
          <label>Rum</label>
        </li>
        <li>
          <a href="/tequila" onClick={() => handleImagePress("Tequila")}>
            <img
              src="https://hips.hearstapps.com/vader-prod.s3.amazonaws.com/1583334281-smirnoff-1583334273.png"
              alt="alcohol-bottle"
              className="selector-bottle-img"
            ></img>
          </a>
          <label>Tequila</label>
        </li>
      </ul>
    </div>
  );
}

const mapDispatchToProps = (dispatch) => {
  return {
    handleCategorySelection: (drinks) =>
      dispatch({ type: "DRINK_LIST", drinkArray: drinks }),
  };
};
export default connect(null, mapDispatchToProps)(Selector);

减速器

const initialState = { drinkList: [] };

const alcoholCategory = (state = initialState, action) => {
  switch (action.type) {
    case "DRINK_LIST":
      return {
        ...state,
        drinkList: state.drinkList.concat(action.drinkArray),
      };
  }
};

export default alcoholCategory;

Answer 1

您可以有条件地围绕它依赖的store属性渲染新组件。

父项：

import React from 'react';
import {connect} from 'redux';
import anyActionYouNeed from '../actions/anyActionYouNeed'

const mapStateToProps = state => {
  return {
    drinkList: state.drinkList,
  }
}

const mapDispatchToProps = {
  anyActionYouNeed
}

//drinkList.length > 0 in your case
let Parent = ({drinkList, anyActionYouNeed}) => {
  return(
    <div>
      {drinkList.length > 0 && <NewComponent drinkList={drinkList}/>}
    </div>
  )
}

Parent = connect(
  mapStateToProps,
  mapDispatchToProps
)(Parent)

export default Parent

React-Redux，如何在渲染新组件之前设置全局状态？

1 个答案: