javascript - redux 道具未定义

我正在尝试编写一个聊天网络应用程序。在下面的代码中，如果我排除了与对话有关的所有代码，它就可以正常工作（如果我只加载用户名并尝试发送消息就可以了）。但是，一旦我添加了与对话有关的所有代码，它就会不断弹出错误消息“this.props.recipients 未定义”。但在我添加任何与对话相关的代码（即 loadConversations() 和对话列表 ()）之前，它运行良好。在添加这些代码之前，我能够访问 this.prop.recipients（如 userList 中所示）。我究竟做错了什么？？

import React from 'react';
import { connect, Provider } from 'react-redux';
import fetch from 'isomorphic-fetch';
import * as actions from './actions/index'


class Chat extends React.Component{ 
    constructor(props){
        super(props);
        this.state = {recipientId: '', messageBuffer:'asdfadsfasdf'};
        this.userList = this.userList.bind(this);
        this.changeRecipient = this.changeRecipient.bind(this);
        this.insertText = this.insertText.bind(this);
    }
    componentWillMount(){
        this.props.loadConversations();

        this.props.loadRecipients();
    }

    userList(){
        if(this.props.recipients.length == 0){
            console.log('why??');   
        }
        else{
            console.log('here');
            console.log(this.props.recipients.length)
            return this.props.recipients.map(user=>(<option key = {user._id} value = {user._id}>{user.name}</option>));
        }
    }


    changeRecipient(e){
        e.preventDefault();
        this.setState({recipientId: e.target.value});
    }

    insertText(e){
        e.preventDefault();
        this.setState({messageBuffer:e.target.value});
    }

    newMessage(e){
        e.preventDefault();
        var recipientId = this.state.recipientId;
        if (recipientId ===''){
            recipientId = this.props.recipients[0]._id;
        }
        console.log(recipientId);
        console.log(this.state.messageBuffer);
        fetch('/newMessage',
        {
            headers: {
              'Accept': 'application/json',
              'Content-Type': 'application/json',
              'Authorization' : localStorage.getItem("token"),

            },
            method: "POST",
            body: JSON.stringify({recipient:recipientId, composedMessage:this.state.messageBuffer})
        })
        .then(function(response) {
            console.log(response);
        })
    }

    conversationList(){
        console.log('in conversation list');
        console.log(this.props.conversations.length);
    }

    render(){

        return (
            <div>
                <form onSubmit = {(e) => this.newMessage(e)}>
                    <select name="recipient" onChange = {(e)=> this.changeRecipient(e)}>
                        {this.userList()}
                    </select>
                    <input type = 'text' name = 'composedMessage' onChange = {(e)=> this.insertText(e)}></input>
                    <input type="submit" value="Submit" ></input>
                </form> 
                {this.conversationList}
            </div>)
    }


}

function mapStateToProps(state) {  
    return {recipients: state.recipients, conversations: state.conversations};
}

export default connect(mapStateToProps, actions)(Chat);

这是我的动作创作者

import {LOAD_RECIPIENTS, LOAD_CONVERSATIONS } from './type'

export function loadRecipients(){
    return function(dispatch){
        fetch("/getRecipients",
        {
            headers: {
              'Accept': 'application/json',
              'Content-Type': 'application/json',
              'Authorization' : localStorage.getItem("token")
            },
            method: "GET",
        })
        .then(function(response) {
            return response.json();
        })
        .then(json=>{
            console.log(json.users);
            console.log('load recipients here!!');
            dispatch({type: LOAD_RECIPIENTS, recipients: json.users});
        })
        .catch(err=>{
            console.log(err);
        });
    }
}

export function loadConversations(){
    return function(dispatch){
        fetch("/getConversations",
        {
            headers: {
              'Accept': 'application/json',
              'Content-Type': 'application/json',
              'Authorization' : localStorage.getItem("token")
            },
            method: "GET",
        })
        .then(function(response) {
            return response.json();
        })
        .then(json=>{
            console.log(json.conversations);
            console.log('load conversations here!!');
            dispatch({type: LOAD_CONVERSATIONS , conversations: json.conversations});
        })
        .catch(err=>{
            console.log(err);
        });
    }
}

这是减速机

import {LOAD_RECIPIENTS,LOAD_CONVERSATIONS} from '../actions/type.js';

const initial = {recipients:[], conversations:[]}


export default function(state = initial, action){
    switch (action.type){
        case LOAD_RECIPIENTS:
            return {recipients : action.recipients};
            break;
        case LOAD_CONVERSATIONS:
            return {conversations : action.conversations};
            break;
        default:
            return state;
    }
}

这是错误信息

堆栈：“userList@ http://localhost:8000/chatbundle.js:24584:1 \nrender@ http://localhost:8000/chatbundle.js:24657:7 \n_renderValidatedComponentWithoutOwnerOrContext/renderedElement<@ http://localhost: 8000/chatbundle.js:19501:16 \nmeasureLifeCyclePerf@ http://localhost:8000/chatbundle.js:18781:12 \n_renderValidatedComponentWithoutOwnerOrContext@ http://localhost:8000/chatbundle.js:19500:25 \renderValidComponentn@ http: //localhost:8000/chatbundle.js:18781:12 //localhost:8000/chatbundle.js:19527:27 \n_updateRenderedComponent@ http://localhost:8000/chatbundle.js:19451:31 \n_performComponentUpdate@ http://localhost:8000/chatbundle.js:19429:5 \更新组件@http://localhost:8000/chatbundle.js:19350:7 \nreceiveComponent@ http://localhost:8000/chatbundle.js:19252:5 \nreceiveComponent@ http://localhost:8000/chatbundle.js:2755: 5 \n_updateRenderedComponent@ http://localhost:8000/chatbundle.js:19459:7 \n_performComponentUpdate@ http://localhost:8000/chatbundle.js:19429:5 \nupdateComponent@ http://localhost:8000/chatbundle。 js:19350:7 \nperformUpdateIfNecessary@ http://localhost:8000/chatbundle.js:19266:7 \nperformUpdateIfNecessary@ http://localhost:8000/chatbundle.js:2787:5 \nrunBatchedUpdates@ http://localhost: 8000/chatbundle.js:1399:5 \nperform@http://localhost:8000/chatbundle.js:3913:13 \nperform@ http://localhost:8000/chatbundle.js:3913:13 \nperform@ http://localhost:8000/chatbundle.js:1338: 12 \nflushBatchedUpdates@ http://localhost:8000/chatbundle.js:1421:7 \ncloseAll@ http://localhost:8000/chatbundle.js:3979:11 \nperform@ http://localhost:8000/chatbundle。 js:3926:11 \nbatchedUpdates@ http://localhost:8000/chatbundle.js:20569:14 \nenqueueUpdate@ http://localhost:8000/chatbundle.js:1449:5 \nenqueueUpdate@ http://localhost: 8000/chatbundle.js:5857:3 \nenqueueSetState@ http://localhost:8000/chatbundle.js:6051:5 \nReactComponent.prototype.setState@http://localhost:8000/chatbundle.js:6663:3 \nonStateChange@ http://localhost:8000/chatbundle.js:10542:11 \ndispatch@ http://localhost:8000/chatbundle.js:10848: 7 \ncreateThunkMiddleware/http://localhost:8000/chatbundle.js:24511:16\ndispatch@ http://localhost:8000/chatbundle.js:24261:18 \nloadConversations/http://localhost:8000/chatbundle。 js:25207:4\n"