狀態在React Redux中未正確更改

Question

我是React Redux的新手，我已經初始化了狀態，可以通過調用其各自的reducer哪個作業來返回初始化狀態來正確顯示該狀態。 但是在改變狀態后，狀態很可能不會改變，我無法弄清楚為什么

import { combineReducers } from 'redux';

const initialState = {
    songs:[
        {title:'No Scrubs', duration: '4:05'},
    ]
}

const songReducers = (state = initialState)=>{
    return state
}

const selectedSongReducer =(selectedSong=null,action)=>{
    if(action.type==='SONG_SELECTED'){
        return action.payload
    }

    return selectedSong;
}


const addSongReducer = (state=initialState,action)=>{
    if(action.type==="ADD_SONG"){
       return {
        ...state,   
        songs:[
           ...state.songs, {title:'All demo', duration: '4:05'}
        ]
    }
    }
    return state;
}

export default combineReducers({
    songs: songReducers,
    selectedSong: selectedSongReducer,
    addSong:addSongReducer
})

Answer 1

您的整體狀態看起來像

state = {
    songs: {
        songs: [
            { title: 'No Scrubs', duration: '4:05' },
        ]
    },
    selectedSong: null,
    addSong: {
        songs: [
            { title: 'No Scrubs', duration: '4:05' },
        ]
    }
}

在第一個reduce調用之后。 這是你想要的嗎？ 問，因為你有

state = {
    songs: {
        songs: [
            { title: 'No Scrubs', duration: '4:05' },
        ]
    },
    ...
}

而不只是

state = {
    songs: [
        { title: 'No Scrubs', duration: '4:05' },
    ]
    ...
}