Question

有人可以帮我使用ReactNative-expo将其转换为React Native Hooks吗？我已经尝试了几个小时，但我不断出错： NSMutableDictionary类型的JSON值无法转换为有效的URL 我无法解决该错误，因此我假设它与componentDidMount有关，并且使用useEffect的方式不正确。预先谢谢你，

import { StyleSheet, Image, View } from 'react-native';
import * as ImagePicker from 'expo-image-picker';
import Constants from 'expo-constants';
import * as Permissions from 'expo-permissions';
import { EvilIcons } from '@expo/vector-icons';


export default class ImagePickerIcon extends React.Component {
    state = {
        image: null,
    };

    componentDidMount() {
        this.getPermissionAsync()
    }
    
    getPermissionAsync = async () => {
        if (Constants.platform.ios) {
            const { status } = await Permissions.askAsync(Permissions.CAMERA_ROLL);
            if (status !== 'granted') {
                alert('Sorry, we need camera roll permissions to make this work!');
            }
        }
    }

    _pickImage = async () => {
        try {
            let result = await ImagePicker.launchImageLibraryAsync({
                mediaTypes: ImagePicker.MediaTypeOptions.All,
                allowsEditing: true,
                aspect: [4, 4],
                quality: 1,
            });
            if (!result.cancelled) {
                this.setState({ image: result.uri })   
            }
        } catch (E) {
            console.log(E);
        }
    }

    render() {
        let { image } = this.state;

        return (
            <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
                <View style={styles.emptyProfile}>
                    {image && <Image source={{ uri: this.state.image }} style={styles.profile} />}
                    <View style={{ left: 140, position: 'absolute', bottom: 50 }} >
                        <View style={styles.camera}>
                            <EvilIcons name='camera' size={35} color='#fff' onPress={this._pickImage} />
                        </View>
                    </View>
                </View>
            </View>
        );
    }
}

const styles = StyleSheet.create({
    camera: {
        backgroundColor: '#ec2327',
        height: 50,
        width: 50,
        borderRadius: 25,
        justifyContent: 'center',
        alignItems: 'center',
        position: 'absolute',
    },
    profile: {
        width: 190,
        height: 190,
        borderRadius: 100,
        justifyContent: 'center',
        alignItems: 'center',
    },
    emptyProfile: {
        width: 200,
        height: 200,
        borderRadius: 100,
        backgroundColor: '#c1b78d',
        borderWidth: 5,
        borderColor: '#fff',
        shadowColor: 'black',
        shadowOffset: { width: 0, height: 3 },
        shadowRadius: 3,
        shadowOpacity: 0.3,
        elevation: 5,
    }

})

Answer 1

export default function ImagePicker() {

    const [image, setImage] = useState(null)

    useEffect(() => {

        getPermissionAsync()

    }, [])

    const getPermissionAsync = async () => {
        if (Constants.platform.ios) {
            const { status } = await Permissions.askAsync(Permissions.CAMERA_ROLL);
            if (status !== 'granted') {
                alert('Sorry, we need camera roll permissions to make this work!');
            }
        }
    };

    const pickImage = async () => {
        try {
            let result = await ImagePick.launchImageLibraryAsync({
                mediaTypes: ImagePick.MediaTypeOptions.All,
                allowsEditing: true,
                aspect: [4, 4],
                quality: 1,
            });
            if (!result.cancelled) {
                console.log({ image: result.uri })
                setImage(result.uri)
                uploadImage(result.uri, auth.currentUser.uid)
                    .then(() => {
                        console.log('success')
                    })
            }
        } catch (E) {
            console.log(E);
        }
    };
return (
        <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
            <View style={styles.emptyProfile}>
                {image && <Image style={styles.profile} source={{ uri: image }} />}
                <View style={{ left: 140, position: 'absolute', bottom: 50 }} >
                    <TouchableOpacity style={styles.camera} onPress={pickImage}>
                        <EvilIcons name='camera' size={35} color='#fff' />
                    </TouchableOpacity>
                </View>
            </View>
        </View>
    )
}

const styles = StyleSheet.create({
    camera: {
        backgroundColor: '#ec2327',
        height: 50,
        width: 50,
        borderRadius: 25,
        justifyContent: 'center',
        alignItems: 'center',
        position: 'absolute',
    },
    profile: {
        width: 190,
        height: 190,
        borderRadius: 100,
        justifyContent: 'center',
        alignItems: 'center',
    },
    emptyProfile: {
        width: 200,
        height: 200,
        borderRadius: 100,
        backgroundColor: '#c1b78d',
        borderWidth: 5,
        borderColor: '#fff',
        shadowColor: 'black',
        shadowOffset: { width: 0, height: 3 },
        shadowRadius: 3,
        shadowOpacity: 0.3,
        elevation: 5,
    }

})

在图像选择器上将类组件转换为功能组件

1 个答案: