Javascript React Native Selected item未将状态反映到UI
我正在尝试开发一个组件,该组件应该显示我数据库中的所有成分,但状态并没有按照预期进行更新 变量:Javascript React Native Selected item未将状态反映到UI,javascript,reactjs,react-native,state,Javascript,Reactjs,React Native,State,我正在尝试开发一个组件,该组件应该显示我数据库中的所有成分,但状态并没有按照预期进行更新 变量: const image = require('../../assets/backgroundMeal.png'); const [name, setName] = useState('') const [ingredients, setIngredients] = useState([]) const [recipes, setRecipes] = useState([]) co
const image = require('../../assets/backgroundMeal.png');
const [name, setName] = useState('')
const [ingredients, setIngredients] = useState([])
const [recipes, setRecipes] = useState([])
const [ingredientList, setIngredientList] = useState([{id:null, name:null, isSelected:false}])
API调用:
useEffect(() => {
let recipeRequest = 'http://192.168.0.3:3333/report'
let ingredientsRequest = 'http://192.168.0.3:3333/ingredients'
recipeRequest = axios.get(recipeRequest)
ingredientsRequest = axios.get(ingredientsRequest)
axios.all([recipeRequest, ingredientsRequest])
.then(axios.spread((...responses) => {
setRecipes(responses[0].data)
setIngredientList(responses[1].data)
}))
.catch(function (error) {
console.log('API CALL - recipe/ingredient - error: ', error);
})
},[ingredientList])
变量“IngCreditsRequest”包含所有成分
这是将“isSelected”与“IngreditList”联接的变量
这是第一个问题,我将形状为“id”和“name”的iguals的状态声明为null,并且useEffect axios调用应更新“setIngredientList”和“ingredientList”,但在“return”之前调用的console.log显示,对象的id值为null,name变量的值为null。它应该在我在useEffect的axios调用中更新,为什么不呢
console.log在“allItems”变量处的结果
排列[
反对{
“id”:空,
“isSelected”:错误,
“名称”:空,
},
单击Flatlist组件后,它正确地更新了“isSelected”状态,但没有显示所有的“IngreditList”状态,即使考虑到“allItems”变量使用useState([IngreditList]),所以我认为它应该具有IngreditList形状,是吗
<FlatList
horizontal
bounces={false}
data={allItems}
renderItem={({ item, index }) => (
<TouchableOpacity key={item.id} onPress={() => selectedIngredient(item, index)}>
<Card key={index}>
<Text key={item.title} style={styles.titleText}>{item.name}</Text>
<Text key={item.title} style={styles.titleText}>{item.isSelected}</Text>
<Text key={item.title} style={styles.titleText}>{item.isSelected?(
<Text style={{color: "red"}}>{"Not Selected"}</Text>
) : (
<Text style={{color: "green"}}>{"Selected"}</Text>
)}</Text>
<ImageBackground key={item.illustration} source={item.illustration} style={styles.cardImage}>
</ImageBackground>
</Card>
</TouchableOpacity>
)
}
keyExtractor={(item) => item.index}
/>
(
SelectedGredient(项目、索引)}>
{item.name}
{item.isSelected}
{item.isSelected(
{“未选定”}
) : (
{“选定”}
)}
)
}
keyExtractor={(项)=>item.index}
/>
有人能帮我吗?非常感谢。试试这个,它会反映用户界面的选择
const selectedIngredient = (item, index) => {
const tempAllItems = [...allItems];
tempAllItems[index].isSelected = !item.isSelected;
setAllItems(tempAllItems);
}
const[allItems,setAllItems]=useState([ingredientList]);
-成分列表已经是一个列表,因此不需要方括号。请尝试:const[allItems,setAllItems]=useState(ingredientList)
希望一切都能正常工作,现在开始工作了,非常感谢您的帮助。除了上面提到的解决方案之外,我还删除了更新状态并生成无限循环的'IngreditList'变量。
const selectedIngredient = (item, index) => {
const tempAllItems = [...allItems];
tempAllItems[index].isSelected = !item.isSelected;
setAllItems(tempAllItems);
}