React-Native：AsyncStorage.getItem不起作用。我已经从react-native-community安装了AsyncStorage

Question

我有一个带按钮的屏幕，用于选择游戏的玩家数量。单击这些按钮中的任何一个都会调用一个函数，将相应的数字传递给函数，将该数字存储在异步存储中，然后导航到下一个屏幕。见下面的代码：

//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来获取此数字，那么我可以用它来做事情，我只是得到null。见下面的代码：

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alert函数来查看使用AsyncStorage.getItem得到的结果，正如我之前所说，它显示为“null”。正如标题中所述，我已经从react-native-community安装了异步存储，并且使用了来自'@ react-native-community / async-storage'的导入AsyncStorage;“。

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)); 

要么

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

请检查一下

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