不变违规:对象作为 React 子对象无效 [英] Invariant Violation: Objects are not valid as a React child

问题描述

在我的组件的渲染函数中，我有:

render() {const items = ['EN', 'IT', 'FR', 'GR', 'RU'].map((item) => {return (<li onClick={this.onItemClick.bind(this, item)} key={item}>{item}</li>);});返回 (<div>...<ul>{项目}...

);}

一切正常，但是当单击

元素时，我收到以下错误:

<块引用>

未捕获的错误:不变违规:对象作为 React 无效子(找到:带有键 {dispatchConfig、dispatchMarker、nativeEvent，目标，currentTarget，类型，eventPhase，气泡，可取消，时间戳，defaultPrevented，isTrusted，查看，详细信息，screenX, screenY, clientX, clientY, ctrlKey, shiftKey, altKey,metaKey，getModifierState，按钮，按钮，相关目标，pageX，pageY, isDefaultPrevented, isPropagationStopped, _dispatchListeners,_dispatchIDs}).如果您打算渲染一组子项，请改用数组或使用 createFragment(object) from 包装对象React 插件.检查Welcome的render方法.

如果我将 this.onItemClick.bind(this, item) 改为 (e) =>地图函数内部的 onItemClick(e, item) 一切正常.

如果有人能解释我做错了什么并解释为什么我会收到这个错误，那就太好了

更新1:
onItemClick 函数如下，去掉 this.setState 导致错误消失.

onItemClick(e, item) {this.setState({lang:项目，});}

但是我不能删除这一行，因为我需要更新这个组件的状态

解决方案

我遇到了这个错误，结果是我无意中在我的 JSX 代码中包含了一个我希望是字符串值的对象:

返回(<BreadcrumbItem href={routeString}>{面包屑元素}</面包屑项目>)

breadcrumbElement 曾经是一个字符串，但由于重构已经变成了一个对象.不幸的是，React 的错误消息并没有很好地将我指向存在问题的那一行.我不得不一直跟踪我的堆栈跟踪，直到我识别出传递给组件的道具"，然后我找到了有问题的代码.

您需要引用作为字符串值的对象的属性，或者将对象转换为所需的字符串表示形式.如果您确实想查看对象的内容，则一种选择可能是 JSON.stringify.

In my component's render function I have:

render() {
    const items = ['EN', 'IT', 'FR', 'GR', 'RU'].map((item) => {
      return (<li onClick={this.onItemClick.bind(this, item)} key={item}>{item}</li>);
    });
    return (
      <div>
        ...
                <ul>
                  {items}
                </ul>
         ...
      </div>
    );
  }

everything renders fine, however when clicking the <li> element I receive the following error:

Uncaught Error: Invariant Violation: Objects are not valid as a React child (found: object with keys {dispatchConfig, dispatchMarker, nativeEvent, target, currentTarget, type, eventPhase, bubbles, cancelable, timeStamp, defaultPrevented, isTrusted, view, detail, screenX, screenY, clientX, clientY, ctrlKey, shiftKey, altKey, metaKey, getModifierState, button, buttons, relatedTarget, pageX, pageY, isDefaultPrevented, isPropagationStopped, _dispatchListeners, _dispatchIDs}). If you meant to render a collection of children, use an array instead or wrap the object using createFragment(object) from the React add-ons. Check the render method of Welcome.

If I change to this.onItemClick.bind(this, item) to (e) => onItemClick(e, item) inside the map function everything works as expected.

If someone could explain what I am doing wrong and explain why do I get this error, would be great

UPDATE 1:
onItemClick function is as follows and removing this.setState results in error disappearing.

onItemClick(e, item) {
    this.setState({
      lang: item,
    });
}

But I cannot remove this line as I need to update state of this component

解决方案

I was having this error and it turned out to be that I was unintentionally including an Object in my JSX code that I had expected to be a string value:

return (
    <BreadcrumbItem href={routeString}>
        {breadcrumbElement}
    </BreadcrumbItem>
)

breadcrumbElement used to be a string but due to a refactor had become an Object. Unfortunately, React's error message didn't do a good job in pointing me to the line where the problem existed. I had to follow my stack trace all the way back up until I recognized the "props" being passed into a component and then I found the offending code.

You'll need to either reference a property of the object that is a string value or convert the Object to a string representation that is desirable. One option might be JSON.stringify if you actually want to see the contents of the Object.

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