使用 UseState React Hook 从子组件更新父组件状态

Question

假设我有一个这样的父组件：

function Recipe(recipe) {
const [pageState, updatePageState] = useState("view");
return (
<div className="border-b-2 border-gray-300 py-2">
<div className="h-full flex-col md:flex md:flex-row md:justify-between md:items-start">
<div
className="order-2 flex flex-col flex-1 px-2 h-full md:h-72 lg:h-64 md:flex-col md:justify-between md:order-1 md:w-1/2 lg:w-3/4"
>          
<RecipeActions pageState = {pageState} triggerParentUpdate = {state => updatePageState(state)} />
</div>
</div>
</div>
)
}

我在下面有一个子组件，我正在尝试更新父组件中的pageState。我尝试了几次迭代，但没有运气。

function RecipeActions(pageState, {triggerParentUpdate}){
const [open, moreActions] = useState(false);
function editRecipe(){
triggerParentUpdate(pageState);
}
return(
<div className="flex">
<span className={`${pageState=='view' ? 'hidden' : ''} ml-1 sm:ml-2 md:ml-1 lg:ml-2 shadow-sm rounded-md`}>
<button
onClick={editRecipe}
type="button"
className="inline-flex items-center px-3 sm:px-4 py-2 border border-gray-300 text-sm leading-5 font-medium rounded-md text-gray-700 bg-white hover:text-gray-500 focus:outline-none focus:shadow-outline-blue focus:border-blue-300 active:text-gray-800 active:bg-gray-50 active:text-gray-800 transition duration-150 ease-in-out"
>
<svg className="h-5 w-5 text-gray-500" fill="currentColor" viewBox="0 0 20 20">
<path d="M17.414 2.586a2 2 0 00-2.828 0L7 10.172V13h2.828l7.586-7.586a2 2 0 000-2.828z" />
<path
fillRule="evenodd"
d="M2 6a2 2 0 012-2h4a1 1 0 010 2H4v10h10v-4a1 1 0 112 0v4a2 2 0 01-2 2H4a2 2 0 01-2-2V6z"
clipRule="evenodd"
/>
</svg>
<p className="hidden sm:block sm:pl-2 md:hidden lg:block">Edit</p>
</button>
</span>
</div>
)
}

Answer 1

我想通了。摘要见下文：

重要的是确保你的 props 作为单个数组传递给你的孩子，你在调用你的函数时应该有一个函数(例如onClick={() => triggerParentUpdate('edit')}(，并且当将更新函数从父级传递给子项时，您需要这样的东西<RecipeActions pageState = {pageState} triggerParentUpdate = {updatePageState} />

父母

function Recipe(recipe) {
const [pageState, setPageState] = useState("view");
const updatePageState = (state) => {
setPageState(state);
} 
return (
<div className="border-b-2 border-gray-300 py-2">
<div className="h-full flex-col md:flex md:flex-row md:justify-between md:items-start">
<div
className="order-2 flex flex-col flex-1 px-2 h-full md:h-72 lg:h-64 md:flex-col md:justify-between md:order-1 md:w-1/2 lg:w-3/4"
>          
<RecipeActions pageState = {pageState} triggerParentUpdate = {updatePageState} />
</div>
</div>
</div>
)
}

孩子

function RecipeActions({pageState, triggerParentUpdate}){
const [open, moreActions] = useState(false);
return(
<div className="flex">
<span className={`${pageState=='view' ? 'hidden' : ''} ml-1 sm:ml-2 md:ml-1 lg:ml-2 shadow-sm rounded-md`}>
<button
onClick={() => triggerParentUpdate('edit')}
type="button"
className="inline-flex items-center px-3 sm:px-4 py-2 border border-gray-300 text-sm leading-5 font-medium rounded-md text-gray-700 bg-white hover:text-gray-500 focus:outline-none focus:shadow-outline-blue focus:border-blue-300 active:text-gray-800 active:bg-gray-50 active:text-gray-800 transition duration-150 ease-in-out"
>
<svg className="h-5 w-5 text-gray-500" fill="currentColor" viewBox="0 0 20 20">
<path d="M17.414 2.586a2 2 0 00-2.828 0L7 10.172V13h2.828l7.586-7.586a2 2 0 000-2.828z" />
<path
fillRule="evenodd"
d="M2 6a2 2 0 012-2h4a1 1 0 010 2H4v10h10v-4a1 1 0 112 0v4a2 2 0 01-2 2H4a2 2 0 01-2-2V6z"
clipRule="evenodd"
/>
</svg>
<p className="hidden sm:block sm:pl-2 md:hidden lg:block">Edit</p>
</button>
</span>
</div>
)
}

这是我从此页面看到的另一个示例

import React from 'react';
function App() {
const [fruits, setFruits] = React.useState([
{ id: '1', name: 'Apple', isFavorite: false },
{ id: '2', name: 'Peach', isFavorite: true },
{ id: '3', name: 'Strawberry', isFavorite: false },
]);
function handleClick(item) {
const newFruits = fruits.map((fruit) => {
if (fruit.id === item.id) {
return {
id: fruit.id,
name: fruit.name,
isFavorite: !fruit.isFavorite,
};
} else {
return fruit;
}
});
setFruits(newFruits);
}
return (
<div>
<h3>with no styling</h3>
<Basket items={fruits} onClick={handleClick} />
</div>
);
}
function Basket({ items, onClick }) {
return (
<ul>
{items.map((item) => (
<li key={item.id}>
{item.name}
<button type="button" onClick={() => onClick(item)}>
{item.isFavorite ? 'Unlike' : 'Like'}
</button>
</li>
))}
</ul>
);
}
export default App;