按下按钮时如何更改主题? (本机反应)

How do I change the theme when I press the button? (React-native)

当我按下按钮时,我希望它获得 button2 主题而不是 buttondefault。我该怎么做? (我在react-native文档里找不到,有没有link?)

export default class deneme extends Component {
  constructor(props) {
    super(props);
    this.state = {
           

    
    };
  }


  render() {
    return (
      <View style={{flex:1, justifyContent:'center', alignItems:'center'}}>

        <TouchableOpacity 
        onPress={() => this.pressme()}
        style={styles.buttondefault}>
        <Text style={{fontSize:40}}> B </Text>
        </TouchableOpacity>

      </View>
    );
  }
}

const styles = StyleSheet.create({
    buttondefault:{
        width:100,
        height:50,
        backgroundColor:'green'
    },

    button2:{
        width:50,
        height:100,
        backgroundColor:'green'
    },


});

您可以为该按钮设置一个状态,单击该按钮将更改状态,进而更改样式,如下所示:

constructor(props) {
  super(props);
  this.state = {
    buttonStyle: 'default' 
  };
}
...
...
<TouchableOpacity 
  onPress={() => this.pressme()}
  style={(this.state.buttonStyle == 'default') ? styles.buttondefault : styles.button2}>
  <Text style={{fontSize:40}}> B </Text>
</TouchableOpacity>
...
...
pressme() {
  this.setState({buttonStyle: 'button2'});
}