TypeError：dispatcher.useState不是React Native的函数

Question

我有一个博览会项目，我想在其中使用挂钩。

启动我的应用程序时出现以下错误：

TypeError: dispatcher.useState is not a function. (In 'dispatcher.useState(initialState)', 'dispatcher.useState' is undefined)

根据another well referenced issue中的建议，我已经更新了package.json，使其包括：

"react": "16.7.0-alpha.2",

，但出现相同的错误。感谢您的帮助。

编辑：删除了Boy With Silver Wings指出的对react-dom的依赖。

Answer 1

在this之后，我编写了一个脚本来解决它。只需定义$MY_NODE_PROJECT_DIR：

git clone https://github.com/facebook/react 

cd react

# files that need to be modified found with grep -lr 'enableHooks = false'
# packages/shared/ReactFeatureFlags.js
# packages/shared/forks/ReactFeatureFlags.test-renderer.js
# packages/shared/forks/ReactFeatureFlags.native-oss.js
# packages/shared/forks/ReactFeatureFlags.persistent.js

# replace enableHooks false with true
grep -lr 'enableHooks = false' | xargs sed -i 's/enableHooks = false/enableHooks = true/g'

yarn install

# this requires JAVA is on your path
# install with `apt install default-jdk`
yarn build -- --type=RN_OSS

# copy the built files into our renderer
cp -R build/react-native/* $MY_NODE_PROJECT_DIR/node_modules/react-native/Libraries/Renderer

根据评论，我从package.json中删除了不必要的依赖项，给出了以下内容（有一些特定于我项目的依赖项）：

{
  "main": "node_modules/expo/AppEntry.js",
  "scripts": {
    "start": "expo start",
    "android": "expo start --android",
    "ios": "expo start --ios",
    "eject": "expo eject",
    "test": "node ./node_modules/jest/bin/jest.js --watchAll"
  },
  "jest": {
    "preset": "jest-expo"
  },
  "dependencies": {
    "@expo/samples": "2.1.1",
    "aws-amplify": "^1.1.12",
    "aws-amplify-react-native": "^2.0.10",
    "expo": "^31.0.2",
    "react": "16.7.0-alpha.2",
    "react-native": "https://github.com/expo/react-native/archive/sdk-31.0.0.tar.gz",
    "react-native-easy-grid": "0.2.0",
    "react-native-swipe-gestures": "1.0.3",
    "react-navigation": "^2.18.2"
  },
  "devDependencies": {
    "@babel/runtime": "7.0.0",
    "@types/react": "^16.7.17",
    "@types/react-native": "^0.57.18",
    "babel-preset-expo": "^5.0.0",
    "jest-expo": "^31.0.0",
    "react-native-typescript-transformer": "^1.2.10",
    "schedule": "^0.4.0",
    "typescript": "^3.2.2"
  },
  "private": true
}

然后正常运行您的应用程序。这是一个示例应用程序，用于测试它是否有效：

import React, { useState } from 'react';
import { StyleSheet, Text, View } from 'react-native';

function Counter() {
  let [count, setCount] = useState(0);

  return <Text onPress={() => setCount(count + 1)}>{count}</Text>;
}

export default class App extends React.Component {
  render() {
    return (
      <View style={styles.container}>
        <Text>Open up App.js to start working on your app!</Text>
        <Counter />
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'center',
  },
});

我的样子：