React Native CameraRoll 权限被拒绝

Question

按下按钮后会执行以下代码：

takePicture = async function() {
    if (this.camera) {
      const options = { quality: 0.5, base64: true }
      const data = await this.camera.takePictureAsync(options)
      CameraRoll.saveToCameraRoll(data.uri)
    }
  }

调试器显示：

Possible Unhandled Promise Rejection
Error: Permission Denied ...

显然，CameraRoll 需要用户的许可才能执行此操作，但我已经将它们包含在我的 AndroidManifest.xml 文件中：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="com.gradualcamera">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.RECORD_AUDIO"/>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

    <application
      android:name=".MainApplication"
      android:label="@string/app_name"
      android:icon="@mipmap/ic_launcher"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:allowBackup="false"
      android:theme="@style/AppTheme">
      <activity
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:configChanges="keyboard|keyboardHidden|orientation|screenSize"
        android:windowSoftInputMode="adjustResize">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
      </activity>
      <activity android:name="com.facebook.react.devsupport.DevSettingsActivity" />
    </application>

</manifest>

整个组件的代码：

import React, {Component} from 'react';
import {StyleSheet, View} from 'react-native'
import { RNCamera } from 'react-native-camera'
import { CameraRoll } from 'react-native'
import ActionButton from 'react-native-action-button'
import Icon from 'react-native-vector-icons/Ionicons'

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center'
  },

  button: {
    height: 200,

    justifyContent: 'flex-end',
    alignItems: 'center'
  },

  actionButtonIcon: {
    fontSize: 20,
    height: 22,
    color: 'white',
  },

});


export default class Cam extends Component {
  constructor() {
    super()
    this.takePicture = this.takePicture.bind(this)
  }

  takePicture = async function() {
    if (this.camera) {
      const options = { quality: 0.5, base64: true }
      const data = await this.camera.takePictureAsync(options)
      CameraRoll.saveToCameraRoll(data.uri)
    }
  }

  render() {
    return (
      <View style={styles.container}>

        <RNCamera
          ref={ref => {this.camera = ref}}
          style={{
            flex: 1,
            width: '100%',
            position: 'relative'
          }}
        >
        </RNCamera>

        <ActionButton size={80} useNativeFeedback={false} buttonColor="rgba(231,76,60,1)">
          <ActionButton.Item useNativeFeedback={false} buttonColor='#9b59b6' title="Settings" onPress={this.props.switchScreen}>
            <Icon name="md-create" style={styles.actionButtonIcon} />
          </ActionButton.Item>
          <ActionButton.Item useNativeFeedback={false} buttonColor='#1abc9c' title="Start" onPress={this.takePicture}>
            <Icon name="md-done-all" style={styles.actionButtonIcon} />
          </ActionButton.Item>

        </ActionButton>

      </View>
    )
  }
}

我已经尝试删除应用程序并重新启动 Metro 服务器。

我从“设置”中手动启用了存储权限，现在可以使用了。但是，当我删除应用程序并再次重新安装时，不会向用户请求存储权限。我尝试使用 react-native-permissions 请求它，但它不起作用：

    componentDidMount() {
      _requestPermission = () => {
        Permissions.request('storage').then(response => {
          // Returns once the user has chosen to 'allow' or to 'not allow' access
          // Response is one of: 'authorized', 'denied', 'restricted', or 'undetermined'
          console.log(response)
        })
      }
    }

在我将 react-native-permissions 方法从 onComponentMount 方法中移除并使用按钮触发它后，不知何故开始工作了。

Answer 1

只需添加这一行AndroidManifest.xml：

<application tag android:requestLegacyExternalStorage="true"

Answer 2

看看这个组件，在使用相机之前检查是否启用了权限。

https://github.com/yonahforst/react-native-permissions