react native访问本机原生相机

要访问本机原生相机，你可以使用React Native内置的CameraRoll组件或者使用第三方库如react-native-camera。下面是使用CameraRoll组件的示例代码:

import React, { useState } from 'react';
import {
  SafeAreaView,
  StyleSheet,
  ScrollView,
  View,
  Text,
  StatusBar,
  Button,
  Image,
  CameraRoll,
} from 'react-native';

const App = () => {
  const [image, setImage] = useState(null);

  const handlePress = async () => {
    try {
      const result = await CameraRoll.getPhotos({ first: 1 });
      const photo = result.edges[0].node.image.uri;
      setImage(photo);
    } catch (error) {
      console.log(error);
    }
  };

  return (
    <>
      <StatusBar barStyle="dark-content" />
      <SafeAreaView>
        <ScrollView contentInsetAdjustmentBehavior="automatic" style={styles.scrollView}>
          <View style={styles.body}>
            <Button title="Take a photo" onPress={handlePress} />
            {image && <Image style={styles.image} source={{ uri: image }} />}
          </View>
        </ScrollView>
      </SafeAreaView>
    </>
  );
};

const styles = StyleSheet.create({
  scrollView: {
    backgroundColor: '#fff',
  },
  body: {
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'center',
  },
  image: {
    width: 200,
    height: 200,
    marginVertical: 20,
  },
});

export default App;

这个示例代码中，我们使用了CameraRoll组件的getPhotos方法来获取相机拍摄照片的URI，并且将其设置为Image组件的source属性。你也可以使用react-native-camera库来访问相机并进行更多的自定义操作。