reactjs - 警告 : getInitialState was defined on DimensionPicker, 一个普通的 JavaScript 类。仅支持使用 React.createClass 创建的类

Question

我正在尝试编写我的第一个 react 控件。这是我写的

import React from 'react';
import DimensionPickerAction from '../actions/DimensionPickerActions.js';
import MovieLensAppStore from '../stores/MovieLensAppStore.js';

class DimensionPicker extends React.Component {

    constructor(props) {
        super(props);
        this.state = { items: [], currentItem: '' };
    }

    getInitialState() {
        this.state = {
            items: MovieLensAppStore.getAttributes(this.props.dimension),
            currentItem : MovieLensAppStore.getCurrentAttribute(this.props.dimension)
        };
    }

    onSelectionChange(newValue) {
        DimensionPickerAction.selectionChange(this.props.dimension, newValue);
    }

    render() {
        var optionNodes = this.state.items.map((item) => {
            if (item === this.state.currentItem) 
                return(<option value="{item}" selected>{item}</option>)             
            else
                return(<option value="{item}">{item}</option>)
        });
        return(<div><select onchange="onSelectionChange">{optionNodes}</select></div>);
    }

}

export default DimensionPicker;

非常令人惊讶的是，我收到了一个错误

Warning: getInitialState was defined on DimensionPicker, a plain JavaScript 
class. This is only supported for classes created using React.createClass. Did 
you mean to define a state property instead?

我发现这非常令人困惑，因为显然我的组件源自 React.Component

Answer 1

埃里克的评论是正确的。您使用的是 ES6 类，这意味着不支持 getInitialState。您需要更改此设置:

class DimensionPicker extends React.Component {

    constructor(props) {
        super(props);
        this.state = { items: [], currentItem: '' };
    }

    getInitialState() {
        this.state = {
            items: MovieLensAppStore.getAttributes(this.props.dimension),
            currentItem : MovieLensAppStore.getCurrentAttribute(this.props.dimension)
        };
    }

对此:

class DimensionPicker extends React.Component {

    constructor(props) {
        super(props);
        this.state = {
            items: MovieLensAppStore.getAttributes(props.dimension),
            currentItem : MovieLensAppStore.getCurrentAttribute(props.dimension)
        };
    }