[英]Why won't my controlled Input component in React update with the state?
I've got a list of ingredients in an "editIngreds" array in my state, eg ['Apple', 'Banana', 'Orange'].我的 state 的“editIngreds”数组中有一个成分列表,例如 ['Apple'、'Banana'、'Orange']。 They are rendered to the DOM via react map function.它们通过 react map function 渲染到 DOM。 I have an edit mode that replaces the text with Input boxes so I can edit the items and save them back to the state array.我有一个编辑模式,用输入框替换文本,因此我可以编辑项目并将它们保存回 state 数组。 However, when typing in the box, nothing happens.但是,在框中键入时,没有任何反应。 console.log shows that editIngreds[i] is indeed being updated when I type a character, however the input boxes do not update with this new value. console.log 显示当我输入一个字符时 editIngreds[i] 确实正在更新,但是输入框不会用这个新值更新。
export default function RecipeCard({ recipe, onEditRecipe, onRemoveRecipe }) {
const ingredients = Object.values(recipe.ingredients);
const ingredientKeys = Object.keys(recipe.ingredients);
const [editIngreds, setEditIngreds] = React.useState(ingredients)
...
const onChangeEditIngreds = (event, i) => {
const value = event.target.value;
const ingreds = editIngreds
ingreds[i] = value;
setEditIngreds(ingreds);
};
...
return (
<ul>
{ingredients.map((ingred, i) => (
<li key={ingredientKeys[i]}>
{editMode ? (
<Input
type="text"
value={editIngreds[i]}
onChange={(e) => onChangeEditIngreds(e,i)}
/>
) : (
<>{ingred}</>
)}
</li>
))}
</ul>
You are mutating the state
.您正在改变state
。 Make a shallow copy of ingredients
before updating在更新之前制作ingredients
的浅拷贝
const onChangeEditIngreds = (event, i) => {
const value = event.target.value;
const ingreds = [...editIngreds];
ingreds[i] = value;
setEditIngreds(ingreds);
};
Rather than using this -> ingredients.map((ingred, i) use this ->而不是使用这个 -> 成分.map((ingred, i) 使用这个 ->
editIngreds.map((ingred, i){
....
<Input
type="text"
value={ingred}
onChange={(e) => onChangeEditIngreds(e,i)}
/>
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.