在React-Native中拍摄照片时使用RNcamera设置曝光量？

import React, { Component } from 'react';
import { View, TouchableOpacity, Text } from 'react-native';
import { RNCamera } from 'react-native-camera';

class CameraScreen extends Component {
  constructor(props) {
    super(props);
    this.camera = null;
    this.state = {
      exposure: 0.5, // 设置默认曝光量为0.5
    };
  }

  takePicture = async () => {
    if (this.camera) {
      const options = { quality: 0.5, base64: true };
      const data = await this.camera.takePictureAsync(options);
      console.log(data.uri);
    }
  };

  render() {
    return (
      <View style={{ flex: 1 }}>
        <RNCamera
          ref={(ref) => {
            this.camera = ref;
          }}
          style={{ flex: 1 }}
          type={RNCamera.Constants.Type.back}
          flashMode={RNCamera.Constants.FlashMode.off}
          exposure={this.state.exposure} // 设置曝光量
        />
        <TouchableOpacity onPress={this.takePicture}>
          <Text>拍照</Text>
        </TouchableOpacity>
      </View>
    );
  }
}

export default CameraScreen;