react-native - react native : Cannot add a child that doesn't have a YogaNode or parent node

Question

刚开始学习 react-native，

我创建了一个单独的文件 flexdemo.js 并创建了如下组件:

import React, { Component } from 'react';
import { View } from 'react-native';

export default class FlexibleViews extends Component {
    render() {
        return (
            <View style={{ flex: 1 }}>
                <View style={{ flex: 1, backgroundColor: "powderblue" }}> </View>
                <View style={{ flex: 2, backgroundColor: "skyblue" }}> </View>
                <View style={{ flex: 3, backgroundColor: "steelblue" }}> </View>
            </View>

        );
    }
}

和 App.js 文件如下:

import React, { Component } from 'react';
import {
  AppRegistry,
  Platform,
  StyleSheet,
  Text,
  View, Image
} from 'react-native';

// import Bananas from './src/banana';
// import LotsOfStyles from './src/styledemo'

import FlexibleViews from './src/flexdemo';

export default class App extends Component {
  render() {
    return (
      // <Bananas name = "Tapan"/>
      <View>
        <FlexibleViews />
      </View>

    );
  }
}

这给了我这个错误:



现在，如果我尝试通过将 flexdemo.js 代码添加到 App.js 来运行代码，那么一切正常。

像这样改变了 App.js:

import React, { Component } from 'react';
import { AppRegistry, View } from 'react-native';

export default class FlexDimensionsBasics extends Component {
  render() {
    return (
      // Try removing the `flex: 1` on the parent View.
      // The parent will not have dimensions, so the children can't expand.
      // What if you add `height: 300` instead of `flex: 1`?
      <View style={{flex: 1}}>
        <View style={{flex: 1, backgroundColor: 'powderblue'}} />
        <View style={{flex: 2, backgroundColor: 'skyblue'}} />
        <View style={{flex: 3, backgroundColor: 'steelblue'}} />
      </View>
    );
  }
}

Answer 1

删除组件内的注释。