camera.takePictureAsync(options) 不是本机相机的反应功能

Question

你好，我是 React Native 的新手，我只是在没有博览会的情况下用相机构建了我的第一个 React Native 项目。我安装了它，npm install react-native-camera然后将它与react-native link react-native-camera. 相机运行成功，但是当我触发捕捉按钮时，它出现了这样的错误....

{ [TypeError: camera.takePictureAsync 不是一个函数。（在“camera.takePictureAsync(options)”中，“camera.takePictureAsync”未定义）] ? 线路：131480，？列：72，？sourceURL: ' http://localhost:8081/index.bundle?platform=android&dev=true&minify=false ' }

这是我的代码看起来像......

import React, { useRef } from 'react'
import { View, Text, StyleSheet, TouchableOpacity } from 'react-native'
import { RNCamera } from 'react-native-camera'


function PlayWithCamera() {

    const camera = useRef(null)

    const takePicture = async () => {
        try {
            const options = { quality: 0.5, base64: true };
            const data = await camera.takePictureAsync(options);
            console.log(data.uri, '<<<<<<<<<<<<<<<<<<<<<');
        } catch (error) {
            console.log(error, "ERROR <<<<<<<<<<<<<")
        }
    };

    return (
        <View style={styles.container}>
            <RNCamera
                ref={camera}
                style={styles.preview}
                type={RNCamera.Constants.Type.back}
                flashMode={RNCamera.Constants.FlashMode.on}
                androidCameraPermissionOptions={{
                    title: 'Permission to use camera',
                    message: 'We need your permission to use your camera',
                    buttonPositive: 'Ok',
                    buttonNegative: 'Cancel'
                }}
                androidRecordAudioPermissionOptions={{
                    title: 'Permission to use audio recording',
                    message: 'We need your permission to use your audio',
                    buttonPositive: 'Ok',
                    buttonNegative: 'Cancel',
                }}
                onGoogleVisionBarcodesDetected={({ barcodes }) => {
                    console.log(barcodes)
                }}
            />
            <View style={{ flex: 1, width: '100%', flexDirection: 'row', justifyContent: 'center', position: 'absolute', bottom: 0 }}>
                <TouchableOpacity style={styles.capture} onPress={takePicture}>
                    <Text style={{ fontSize: 14 }}> SNAP </Text>
                </TouchableOpacity>
            </View>
        </View>
    )
}

const styles = StyleSheet.create({
    container: {
        flex: 1,
        flexDirection: 'column',
        backgroundColor: 'black',
    },
    preview: {
        flex: 1,
        justifyContent: 'flex-end',
        alignItems: 'center',
    },
    capture: {
        flex: 0,
        backgroundColor: '#fff',
        borderRadius: 5,
        padding: 15,
        paddingHorizontal: 20,
        alignSelf: 'center',
        margin: 20,
    },
})

export default PlayWithCamera

更新（18.48）：我尝试像在react-native-camera文档中那样使用类组件，它终于起作用了。但我仍然好奇如何让它在函数组件中工作？

Answer 1

您应该使用camera.current.takePictureAsync(options);而不是camera.takePictureAsync(options);.