reactjs - 如何在 React 或 React Native 上使用 useMutation 或 useQuery 作为钩子(Hook)？

Question

那是我得到的异常(exception)......而且这对我来说没有意义......

无效的钩子(Hook)调用。钩子(Hook)只能在函数组件的主体内部调用。这可能是由于以下原因之一造成的:
1. 你的 React 和渲染器的版本可能不匹配(例如 React DOM)
2. 你可能违反了 Hooks 规则
3.你可能在同一个应用中拥有多个 React 副本
有关如何调试和修复此问题的提示，请参阅 fb.me/react-invalid-hook-call。

这是我的组件......我正在尝试存档一个标准的登录/密码屏幕......

import React from 'react'
import { View, Text, TouchableWithoutFeedback, TextInput } from 'react- 
native'
import style from './style'
import { FontAwesomeIcon } from '@fortawesome/react-native-fontawesome'
import { faUser, faUnlockAlt } from '@fortawesome/free-solid-svg-icons'
import { Query, useMutation } from 'react-apollo'
import { testQuery, LOGIN_MUTATION } from '../../gql/session'

class LoginForm extends React.Component {
constructor(props) {
    super(props)
    this.state = {
        inProgress: false,
        email: 'hello@hello.com',
        password: '1234'
    }
}
doLogin() {
    const [_doLogin ] = useMutation(LOGIN_MUTATION, {
        update: (proxy, mutationResult) => {
            console.log(mutationResult)
        }
    ,
    variables: {
      $email: this.setState.email,
      $password: this.state.password
    }
    })
     _doLogin()
}
render() {
    return (
        <View style={style.form}>
            <Text style={style.formLabel}>E-Mail</Text>
            <View style={style.formRow}>
                <FontAwesomeIcon size={28} style={style.formIcon} icon={faUser} />
                <TextInput
                    onChangeText={(email) => this.setState({ email })}
                    value={this.state.email}
                    keyboardType={'email-address'}
                    style={style.textInput} />
            </View>
            <Text style={style.formLabel}>Password</Text>
            <View style={style.formRow}>
                <FontAwesomeIcon size={28} style={style.formIcon} icon={faUnlockAlt} />
                <TextInput
                    onChangeText={(password) => this.setState({ password })}
                    value={this.state.password}
                    secureTextEntry={true}
                    style={style.textInput} />
            </View>

            <TouchableWithoutFeedback onPress={() => { this.doLogin() }}>
                <View style={[style.button, style.doLoginButton]}>
                    <Text style={style.buttonText}>Login</Text>
                </View>
            </TouchableWithoutFeedback>
            <View style={style.bellowButton}>
                <TouchableWithoutFeedback onPress={() => this.props.onCancel()}>
                    <Text style={style.cancel}>Cancel</Text>
                </TouchableWithoutFeedback>
                <TouchableWithoutFeedback onPress={() => this.props.onForgot()}>
                    <Text style={style.forgot}>Forgot ?</Text>
                </TouchableWithoutFeedback>
            </View>
        </View>
    )
   }
}


export default LoginForm

那么，怎么了？以及如何存档？

Answer 1

你得到的错误是因为你试图在类组件中使用钩子(Hook)，所以在 docs 中他们提到了以下几点:

You can’t use Hooks inside of a class component, but you can definitely mix classes and function components with Hooks in a single tree. Whether a component is a class or a function that uses Hooks is an implementation detail of that component. In the longer term, we expect Hooks to be the primary way people write React components.