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我還在學習React-Redux。我明白如何檢索簡單的JSON數組/對象。但是,我不知道如何調用嵌套對象。當它捆綁在一起時,我正在查看'after'對象 - t3_5t61fz - 顯然是因爲我正在調用data.after,但是當我嘗試實現data.title時,什麼也沒有顯示。我試圖抓住標題和我在控制檯中查看此:如何檢索React-Redux中的嵌套JSON對象?
- 對象
- 數據:對象
- 數據:對象
- 數據:對象
- 之後:「t3_5t61fz」之前:nullchildren:Array [25]
- 0:對象
- 數據:對象
- 標題: 「谷歌如何建立一個Web框架」
- 數據:對象
- 0:對象
- 之後:「t3_5t61fz」之前:nullchildren:Array [25]
- 數據:對象
- 數據:對象
- 數據:對象
減速機:
export default function reducer(state={
data: {
data: {}
},
fetching: false,
fetched: false,
error: null,
}, action) {
switch(action.type){
case "FETCH_DATA":{
return {...state, fetching:true}
}
case "FETCH_DATA_REJECTED":{
return {...state, fetching: false, error: action.payload}
}
case "FETCH_DATA_FULFILLED":{
return {...state, fetching: false, fetched: true, data: action.payload}
}
case "ADD_DATA":{
return {...state, data: [...state.data, action.payload]}
}
case "UPDATE_DATA":{
const { id, title } = action.payload
const newData = [...state.data]
const dataToUpdate = newData.findIndex(data => data.id === id)
newData[dataToUpdate] = action.payload;
return {...state, data: newData}
}
case "DELETE_DATA":{
return {...state, data: state.data.filter(data => data.id !== action.payload)}
}
}
return state
}
行動
import axios from 'axios';
export function fetchData(){
return function(dispatch){
axios.get("https://www.reddit.com/r/webdev/top/.json")
.then((response) => {
dispatch({ type: "FETCH_DATA_FULFILLED", payload: response.data})
})
.catch((err) => {
dispatch({type: "FETCH_DATA_REJECTED", payload: err})
})
}
}
export function addData(id, text){
return {
type: 'ADD_DATA',
payload:{
id,
data,
},
}
}
export function updateData(id, text){
return {
type: 'UPDATE_DATA',
payload: {
id,
data,
},
}
}
export function deleteData(id){
return {
type: 'DELETE_DATA',
payload: id
}
}
Layout.js
import React from "react"
import { connect } from "react-redux"
import { fetchData } from "../actions/dataActions"
@connect((store) => {
return {
data: store.data.data
};
})
export default class Layout extends React.Component {
componentWillMount() {
this.props.dispatch(fetchData())
}
render() {
const { data } = this.props;
return <div>
<h1>{data.data.after}</h1>
</div>
}
}
我得到這個錯誤'不能讀屬性'0'未定義':( – userlkjsflkdsvm