如何在react-native中使用另一个组件的变量

问题描述

嗨，亲爱的，感谢您转来帮助我，我有一个名为 PlayerWidget 的组件，我想使用它，状态变量是 AlbumHeader 组件中的 isPlaying 值

这是我的代码

播放器小部件

import React,{ useContext,useEffect,useState } from 'react';
import { Text,Image,View,TouchableOpacity } from 'react-native';
import { AntDesign,FontAwesome } from "@expo/vector-icons";
import { API,graphqlOperation } from 'aws-amplify';

import styles from './styles';
import { Song } from "../../types";
import { Sound } from "expo-av/build/Audio/Sound";

import { AppContext,Status } from '../../AppContext';
import { getSong } from "../../src/graphql/queries";

const PlayerWidget = () => {

    const [song,setSong] = useState(null);
    const [sound,setSound] = useState<Sound | null>(null);
    //this is the Variable I will like to use in my AlbumHeader Component isPlaying
    const [isPlaying,setIsPlaying] = useState<boolean>(true);

    const [duration,setDuration] = useState<number | null>(null);
    const [position,setPosition] = useState<number | null>(null);

    //const { songStatus,setSongStatus } = useContext(Status);

    setSongStatus(isPlaying);
    

    const { songId } = useContext(AppContext);



    useEffect(() => {
        const fetchSong = async () => {
            try {
                const data = await API.graphql(graphqlOperation(getSong,{ id: songId }))

                setSong(data.data.getSong);
            } catch (e) {
                console.log(e);
            }
        }

        fetchSong();
    },[songId])

    const onPlaybackStatusUpdate = (status) => {
        setIsPlaying(status.isPlaying);
        setDuration(status.durationMillis);
        setPosition(status.positionMillis);


    }

    const playCurrentSong = async () => {

        if (song.artist.length > 10) {
            song.artist = song.artist.substring(0,6) + "...";
        }

        if (song.title.length > 8) {
            song.title = song.title.substring(0,5) + "...";
        }
        if (sound) {
            await sound.unloadAsync();
        }

        const { sound: newSound } = await Sound.createAsync(
            { uri: song.uri },{ shouldplay: isPlaying },onPlaybackStatusUpdate
        )

        setSound(newSound)
    }

    useEffect(() => {
        if (song) {
            playCurrentSong();
        }
    },[song])

    const onPlayPausePress = async () => {
        if (!sound) {
            return;
        }
        if (isPlaying) {
            await sound.stopAsync();
        } else {
            await sound.playAsync();
        }
    }

    const getProgress = () => {
        if (sound === null || duration === null || position === null) {
            return 0;
        }

        return (position / duration) * 100;
    }

    if (!song) {
        return null;
    }

    return (
        <View style={styles.container}>
            <View style={[styles.progress,{ width: `${getProgress()}%` }]} />
            <View style={styles.row}>
                <Image source={{ uri: song.imageUri }} style={styles.image} />
                <View style={styles.rightContainer}>
                    <View style={styles.nameContainer}>
                        <Text style={styles.title}>{song.title}</Text>
                        <Text style={styles.artist}>{song.artist}</Text>
                    </View>

                    <View style={styles.iconsContainer}>
                        <AntDesign name="hearto" size={20} color={'white'} />
                        <TouchableOpacity onPress={onPlayPausePress}>
                            <AntDesign name={isPlaying ? 'pausecircleo' : 'playcircleo'} size={25} color={'white'} />
                        </TouchableOpacity>

                    </View>

                </View>

            </View>

        </View>
    )
}


export default PlayerWidget;

这是另一个（专辑标题）组件，我想在其中使用 isPlaying 值

import React from 'react';
import { useContext } from 'react';
import { View,Text,Image } from 'react-native';
import { TouchableOpacity } from 'react-native-gesture-handler';
import { AppContext,Status } from '../../AppContext';
import { Album } from '../../types';
import styles from './styles';


export type AlbumHeaderProp = {
    album: Album;
}

const AlbumHeader = (props: AlbumHeaderProp) => {

    const { album } = props;

    const { setSongId,songId } = useContext(AppContext);
    var playalbumSong = new Array();

    const { songStatus } = useContext(Status);

    const playallSong = () => {
        const name = 'name';

        console.log("I will play all the songs George huum");
        const myArray = album.songs.items;

        myArray.forEach((element: any,index: number,array: any) => {
            playalbumSong.push(element.id);
          

        });


        console.log(songStatus);
        setSongId(playalbumSong[0]);

    }
    return (
        <View style={styles.container}>
            <Image source={{ uri: album.imageUri }} style={styles.image} />
            <Text style={styles.name}>{album.name}</Text>

            <View style={styles.creatorContainer}>
                <Text style={styles.creator}>By {album.by}</Text>
                <Text style={styles.likes}>{album.numberOfLikes} Likes</Text>
            </View>
            <TouchableOpacity onPress={playallSong}>
                <View style={styles.button}>
                    <Text style={styles.buttonText}>Play</Text>
                </View>
            </TouchableOpacity>

        </View>
    )
}

export default AlbumHeader;

解决方法

如果 AlbumHeader 不是 PlayerWidget 的子项，则您也需要使用全局状态，例如react-redux 或 reducer 钩子。

,

我通过将该变量的值传递给相同类型的上下文来解决这个问题，如果您使用 react hook 和功能组件，则此方法有效