反应本机使用状态
React Native useState
当我尝试使用 useState 时出现此错误:
组件异常
(0,_reactNative.useState) 不是函数。(在'(0,_reactNative.useState)(false)','(0,reactNative.useState)'中未定义)
来源
var children = Component(props, secondArg);
请帮帮我。我不明白为什么我不能使用 useState:(
这是我的代码:
`
import React from 'react';
import {StyleSheet,View,Text, Modal,useState} from 'react-native';
import { createAppContainer,NavigationContainer } from 'react-navigation';
import { createStackNavigator } from 'react-navigation-stack';
import HomeScreen from './android/screens/HomeScreen/index';
import LoginScreen from './android/screens/Login/index'
const AppNavigator = createStackNavigator(
{
Home: {screen: HomeScreen},
Login: {screen: LoginScreen},
},
{
initialRouteName:'Login'
}
);
const AppContainer= createAppContainer(AppNavigator);
export default function App () {
const [modalVisible, setModalVisible] = useState(false);
return (
<AppContainer/>
)
}
正如 Nicholas 所指出的,从 react
而不是 react-native
、
导入 useState
import React, {useState} from 'react';
import {StyleSheet,View,Text, Modal} from 'react-native';
当我尝试使用 useState 时出现此错误: 组件异常
(0,_reactNative.useState) 不是函数。(在'(0,_reactNative.useState)(false)','(0,reactNative.useState)'中未定义)
来源 var children = Component(props, secondArg);
请帮帮我。我不明白为什么我不能使用 useState:(
这是我的代码: `
import React from 'react';
import {StyleSheet,View,Text, Modal,useState} from 'react-native';
import { createAppContainer,NavigationContainer } from 'react-navigation';
import { createStackNavigator } from 'react-navigation-stack';
import HomeScreen from './android/screens/HomeScreen/index';
import LoginScreen from './android/screens/Login/index'
const AppNavigator = createStackNavigator(
{
Home: {screen: HomeScreen},
Login: {screen: LoginScreen},
},
{
initialRouteName:'Login'
}
);
const AppContainer= createAppContainer(AppNavigator);
export default function App () {
const [modalVisible, setModalVisible] = useState(false);
return (
<AppContainer/>
)
}
正如 Nicholas 所指出的,从 react
而不是 react-native
、
import React, {useState} from 'react';
import {StyleSheet,View,Text, Modal} from 'react-native';