所以我遇到了这个问题，我用一种奇怪的方式解决了它。我想我应该把它扔了，以防其他人遇到它，变得绝望。

我有一个有条件地呈现react元素，它只在对象状态大于零时才会呈现。在呈现函数中-当三元运算符被证明为真时，我收到了这篇文章所涉及的错误。我使用了一个<React。片段>在我的渲染函数-这是我通常分组子的方式，而不是更新的方式与更新的短语法(<>和</>)。

However, when I changed the <React.Fragment> to the short syntax - the react element rendered correctly and the error stopped appearing. I took a look at Facebooks React-Fragment documentation, and I don't see any reason on there to believe there is a dramatic difference between the two that would cause this. Regardless, below are two simplified snippets of code for your review. The first one demonstrates the code that was yielding the error, and the second one demonstrates the code that fixed the issue. At the bottom is the render function of the component itself.

希望有人觉得这有帮助。

代码示例1 -错误 有条件渲染的React元素

  renderTimeFields = () => {
    return (
      <React.Fragment>
        <div className="align-left">
                <div className="input-row">
                  <label>Date: </label>
                  <input type="date" className="date" name="date" min={new Date().toISOString().split('T')[0]} required/>
                </div>
              </div>
              <div className="align-left sendOn-row">
                <div className="input-row">
                  <label>Time: </label>
                  <input type="time" className="time" name="time" required/>
                </div>
              </div>
      </React.Fragment>
    );
  }

代码示例2 -无错误 有条件渲染的React元素

  renderTimeFields = () => {
    return (
      <>
        <div className="align-left">
                <div className="input-row">
                  <label>Date: </label>
                  <input type="date" className="date" name="date" min={new Date().toISOString().split('T')[0]} required/>
                </div>
              </div>
              <div className="align-left sendOn-row">
                <div className="input-row">
                  <label>Time: </label>
                  <input type="time" className="time" name="time" required/>
                </div>
              </div>
      </>
    );
  }

在组件中呈现函数

render() {
<form>
...
{emailsInActiveScript > 1 ? this.renderTimeFields() : null}
</form>
etc...
}

在我的情况下，我只需要从react-router-redux升级到react-router-redux@next。我猜肯定是兼容性问题。

这并不是一个与进出口直接相关的问题。在我的例子中，我是在父元素中呈现子元素，并且子元素有jsx element / tag，它被使用但没有导入。我导入并使用它，然后它解决了这个问题。所以问题是在jsx元素里面的子元素，而不是导出子元素本身。

如果在测试组件时出现此错误，请确保每个子组件在单独运行时都能正确呈现，如果其中一个子组件依赖于外部资源来呈现，请尝试使用jest或任何其他mock库来模拟它:

示例:

jest.mock('pathToChildComponent', () => 'mock-child-component')

// @flow

import React from 'react';
import { styleLocal } from './styles';
import {
  View,
  Text,
  TextInput,
  Image,
} from 'react-native';
import { TouchableOpacity } from 'react-native-gesture-handler';

export default React.forwardRef((props, ref) => {
const { onSeachClick, onChangeTextSearch , ...otherProps } = props;

  return (
        <View style={styleLocal.sectionStyle}>
        <TouchableOpacity onPress={onSeachClick}>
            <Image                              
                    source={require('../../assets/imgs/search.png')}
                    style={styleLocal.imageStyle} />
                </TouchableOpacity>
            <TextInput
                style={{ flex: 1, fontSize: 18 }}
                placeholder="Search Here"
                underlineColorAndroid="transparent"
                onChangeText={(text) => { onChangeTextSearch(text) }}
            />
        </View>
  );
});
 import IGPSSearch from '../../components/IGPSSearch';
<Search onSeachClick={onSeachClick} onChangeTextSearch= {onChangeTextSearch}> </Search>

我丢失了一个React片段:

function Bar({ children }) {

  return (
    <div>
     {children}
    </div>
  );
}

function Foo() {
  return (
    <Bar>
      <Baz/>
      <Qux/>
    </Bar>
  );
}

上面的代码抛出上面的错误。但这就解决了问题:

<Bar>
  <>
    <Baz/>
    <Qux/>
  </>
</Bar>