React-Native：AsyncStorage.getItem 不工作。我已经从 react-native-community 安装了 AsyncStorage

Question

我有一个屏幕，上面有 select 游戏玩家数量的按钮。单击这些按钮中的任何一个都会调用一个函数，将适当的数字传递给该函数，将该数字存储在异步存储中，然后导航到下一个屏幕。请参阅下面的代码：

//Example of the buttons:
<Text style={styles.text}>
  How Many Players?
</Text>
<PrimaryButton
  onPress={() => this.startRound(3)}
  label="3"
>
</PrimaryButton>
<PrimaryButton
  onPress={() => this.startRound(4)}
  label="4"
>
</PrimaryButton>

//The function:
startRound = (num_players) => {
  AsyncStorage.setItem('Num_Players', num_players);
  this.props.navigation.navigate('player_names_screen');
}

在下一个屏幕上，如果我尝试使用 AsyncStorage.getItem 来获取这个数字，以便我可以用它做一些事情，我只会得到 null。请参阅下面的代码：

constructor (props) {
        super(props);
        this.state = {
            get_players: null
        }
    }

    componentWillMount = () => {
        this.getNumPlayers();
        var players = this.state.get_players;
        alert(players);
    }

    getNumPlayers = async () => {
        let players = await AsyncStorage.getItem('Num_Players');
        this.setState({get_players: players});
    }

我正在使用警报功能查看使用 AsyncStorage.getItem 得到的结果，正如我之前所说，它显示 "null"。正如标题中所说，我已经从 react-native-community 安装了 async-storage 并正在使用 "import AsyncStorage from '@react-native-community/async-storage';".

Answer 1

AsyncStorage 无法存储整数值以将整数值转换为字符串

AsyncStorage.setItem('Num_Players', JSON.stringify(num_players));

或者

AsyncStorage.setItem('Num_Players', ''+num_players);

请检查这个

https://snack.expo.io/@vishal7008/convert-variable-stored-in-asyncstorage-then-state-to-number

React-Native：AsyncStorage.getItem 不工作。我已经从 react-native-community 安装了 AsyncStorage

React-Native: AsyncStorage.getItem not working. I have installed AsyncStorage from react-native-community

javascript

react-native

asyncstorage