Question

我尝试在我的React-Native应用程序上首次实现Redux。我遇到错误找不到变量：渲染

在我的index.js上，我调用了提供程序以使用Redux。所以我添加了一个渲染器，它触发了这个错误。

这是我的index.js文件：

//index.js
import React from "react";
import {AppRegistry} from 'react-native';
import App from './App';
import { Provider } from 'react-redux'
import Store from './redux/Store/store'
import {name as appName} from './app.json';

AppRegistry.registerComponent(appName, () => App);

render(
  <Provider store={Store}>
    <App/>
  </Provider>,
  document.getElementById('root')
)

如果有用，则称为：

的应用程序组件

import firebase from '@firebase/app'
import '@firebase/auth'
import React from 'react';
import { View, Text, Button, Image, TouchableOpacity, StyleSheet } from 'react-native';
import { createStackNavigator, StackActions, NavigationActions } from 'react-navigation'; // Version can be specified in package.json
import Listing from './Listing';
import Menu from './Menu';
import Login from './Login';
import TestRedux from './redux/Components/TestRedux';

firebase.initializeApp({
    apiKey: "XXXXXXX",
    authDomain: "XXXXXXX",
    databaseURL: "XXXXXXX",
    projectId: "XXXXXXX",
    storageBucket: "XXXXXXX",
    messagingSenderId: "XXXXXXX"
});

export class App extends React.Component {
  constructor(props){
    super(props);
    this.state = {
      user:'',
      loggedAndVerifiedOrNot: false
    }

   firebase.auth().onAuthStateChanged((user) => {
        //this.setState({ user: user })
        if (user != null) {
            if (user.emailVerified!=null)
            {
              if (user.emailVerified == true)
              this.setState({loggedAndVerifiedOrNot: true})
            }
        }
    });
  }

  render(){
      if (this.state.loggedAndVerifiedOrNot) {
            this.props.navigation.navigate('Menu');         
      } 
      else {
            this.props.navigation.navigate('Login');
      }
      return (null)
  }
}

export default createStackNavigator({
    Home: {
      screen: App,
    },
    Login: {
      screen: Login,
    },
    Menu: {
      screen: Menu,
    },
    Listing: {
      screen: Listing,
    },
    TestRedux: {
      screen: TestRedux,
    },
  }, 
  {
    initialRouteName: 'Home',
  }
);

您知道此错误来自何处以及如何解决吗？

Answer 1

语法是：

SELECT
    review_id,
    review_id NOT IN (
        SELECT DISTINCT review_id
        FROM review_migration_table
        WHERE filter_column = 170938 and review_id IS NOT NULL)
FROM review_table
WHERE
    filter_column = 170938
ORDER BY review_id ASC

还有这个

render() {
    return ( ... somethingToRender ... )
}

需要在您的App组件内部，并从index.js中删除。

您不需要document.getElementById。应用程序本质上是您的根元素

React Native-找不到变量：渲染

1 个答案: