zoukankan      html  css  js  c++  java
  • ReactNative: 了解相机第三方库react-native-camera的使用

    一、简介

    在前一篇文章中,初步介绍了RN提供的关于相机功能CameraRoll的使用了。很多时候,这种最基础的API有时很难满足功能需求,此时,如果不想重复造轮子,我们可以选择一个完善好用的第三库。react-native-camera就是一个非常不错的关于相机功能的第三方库,使用这个框架基本能满足大多数的需求,现在来简单研究一下。

    二、安装

    1、同样地道理,使用之前得先安装,还是采用npm安装吧。如下:

    //安装react-native-camera
    npm install react-native-camera@latest --save

    2、安装完成之后,需要添加工程,进行编译配置。执行完了这些步骤后,就完成了第三方库的添加了。

    (1)打开xcode,找到Libraries文件,添加安装的react-native-camera目录下的RNCamera.xcodeproj工程

    (2)添加libRNCamera.a静态库

    (3)找到并选中添加的RNCamera.xcodeproj工程,配置Build Settings选项卡中的Header Search Paths路径

    三、API

    1、类RNCamera的定义如下:包含静态常量和函数

    //类RNCamera
    //继承RNCameraProps属性和ViewProperties属性
    export class RNCamera extends Component<RNCameraProps & ViewProperties> {
      
      //静态常量(属性),只读,不可修改
      static Constants: Constants;
    
      _cameraRef: null | NativeMethodsMixinStatic;
      _cameraHandle: ReturnType<typeof findNodeHandle>;
    
      //异步拍照  
      //参数 TakePictureOptions:表示的一下拍照时相机的配置选项
      //返回值 Promise: 异步函数,TakePictureResponse为拍照的响应
      takePictureAsync(options?: TakePictureOptions): Promise<TakePictureResponse>;
    
      //异步录制 
      //参数 RecordOptions:表示的一下录制时相机的配置选项
      //返回值 Promise: 异步函数,RecordResponse为录制的响应
      recordAsync(options?: RecordOptions): Promise<RecordResponse>;
    
      //刷新认证状态
      //返回值 Promise: 异步函数,void无结果
      refreshAuthorizationStatus(): Promise<void>;
    
      //停止录制
      stopRecording(): void;
    
      //暂停预览
      pausePreview(): void;
    
      //恢复预览
      resumePreview(): void;
    
      //获取可用的图片的尺寸
      //返回值 Promise: 异步函数,字符串结果
      getAvailablePictureSizes(): Promise<string[]>;
    
      /** Android only */
      //是否支持异步比率
      getSupportedRatiosAsync(): Promise<string[]>;
    
      /** iOS only */
      //是否正在录制
      isRecording(): Promise<boolean>;
    }

    2、关于RNCameraProps、Constants、TakePictureOptions、TakePictureResponse、RecordOptions、RecordResponse这些对象的定义,分别如下:

    RNCameraProps:相机的配置属性

    export interface RNCameraProps {
      children?: ReactNode | FaCC;
    
      autoFocus?: keyof AutoFocus;
      autoFocusPointOfInterest?: Point;
      /* iOS only */
      onSubjectAreaChanged?: (event: { nativeEvent: { prevPoint: { x: number; y: number; } } }) => void;
      type?: keyof CameraType;
      flashMode?: keyof FlashMode;
      notAuthorizedView?: JSX.Element;
      pendingAuthorizationView?: JSX.Element;
      useCamera2Api?: boolean;
      exposure?: number;
      whiteBalance?: keyof WhiteBalance;
      captureAudio?: boolean;
    
      onCameraReady?(): void;
      onStatusChange?(event: {
        cameraStatus: keyof CameraStatus;
        recordAudioPermissionStatus: keyof RecordAudioPermissionStatus;
      }): void;
      onMountError?(error: { message: string }): void;
    
      /** iOS only */
      onAudioInterrupted?(): void;
      onAudioConnected?(): void;
    
      /** Value: float from 0 to 1.0 */
      zoom?: number;
      /** iOS only. float from 0 to any. Locks the max zoom value to the provided value
        A value <= 1 will use the camera's max zoom, while a value > 1
        will use that value as the max available zoom
      **/
      maxZoom?: number;
      /** Value: float from 0 to 1.0 */
      focusDepth?: number;
    
      // -- BARCODE PROPS
      barCodeTypes?: Array<keyof BarCodeType>;
      googleVisionBarcodeType?: Constants['GoogleVisionBarcodeDetection']['BarcodeType'];
      googleVisionBarcodeMode?: Constants['GoogleVisionBarcodeDetection']['BarcodeMode'];
      onBarCodeRead?(event: {
        data: string;
        rawData?: string;
        type: keyof BarCodeType;
        /**
         * @description For Android use `{  number, height: number, origin: Array<Point<string>> }`
         * @description For iOS use `{ origin: Point<string>, size: Size<string> }`
         */
        bounds: {  number, height: number, origin: Array<Point<string>> } | { origin: Point<string>; size: Size<string> };
      }): void;
    
      onGoogleVisionBarcodesDetected?(event: {
        barcodes: Barcode[];
      }): void;
    
      // -- FACE DETECTION PROPS
    
      onFacesDetected?(response: { faces: Face[] }): void;
      onFaceDetectionError?(response: { isOperational: boolean }): void;
      faceDetectionMode?: keyof FaceDetectionMode;
      faceDetectionLandmarks?: keyof FaceDetectionLandmarks;
      faceDetectionClassifications?: keyof FaceDetectionClassifications;
      trackingEnabled?: boolean;
    
      onTextRecognized?(response: { textBlocks: TrackedTextFeature[] }): void;
      // -- ANDROID ONLY PROPS
      /** Android only */
      ratio?: string;
      /** Android only - Deprecated */
      permissionDialogTitle?: string;
      /** Android only - Deprecated */
      permissionDialogMessage?: string;
      /** Android only */
      playSoundOnCapture?: boolean;
    
      androidCameraPermissionOptions?: {
        title: string;
        message: string;
        buttonPositive?: string;
        buttonNegative?: string;
        buttonNeutral?: string;
      } | null;
    
      androidRecordAudioPermissionOptions?: {
        title: string;
        message: string;
        buttonPositive?: string;
        buttonNegative?: string;
        buttonNeutral?: string;
      } | null;
    
      // -- IOS ONLY PROPS
      defaultVideoQuality?: keyof VideoQuality;
      /* if true, audio session will not be released on component unmount */
      keepAudioSession?: boolean;
    }

    Constants:相机的静态常量属性,都是只读的

    export interface Constants {
      CameraStatus: CameraStatus;
      AutoFocus: AutoFocus;
      FlashMode: FlashMode;
      VideoCodec: VideoCodec;
      Type: CameraType;
      WhiteBalance: WhiteBalance;
      VideoQuality: VideoQuality;
      BarCodeType: BarCodeType;
      FaceDetection: {
        Classifications: FaceDetectionClassifications;
        Landmarks: FaceDetectionLandmarks;
        Mode: FaceDetectionMode;
      };
      GoogleVisionBarcodeDetection: {
        BarcodeType: GoogleVisionBarcodeType;
        BarcodeMode: GoogleVisionBarcodeMode;
      };
      Orientation: {
        auto: 'auto';
        landscapeLeft: 'landscapeLeft';
        landscapeRight: 'landscapeRight';
        portrait: 'portrait';
        portraitUpsideDown: 'portraitUpsideDown';
      };
    }

    TakePictureOptions:拍照时的配置选项

    interface TakePictureOptions {
      quality?: number;
      orientation?: keyof Orientation | OrientationNumber;
      base64?: boolean;
      exif?: boolean;
      width?: number;
      mirrorImage?: boolean;
      doNotSave?: boolean;
      pauseAfterCapture?: boolean;
      writeExif?: boolean | { [name: string]: any };
    
      /** Android only */
      fixOrientation?: boolean;
    
      /** iOS only */
      forceUpOrientation?: boolean;
    }

    TakePictureResponse:拍照后的响应结果

    export interface TakePictureResponse {
       number;
      height: number;
      uri: string;
      base64?: string;
      exif?: { [name: string]: any };
      pictureOrientation: number;
      deviceOrientation: number;
    }

    RecordOptions:录制时的配置选项

    interface RecordOptions {
      quality?: keyof VideoQuality;
      orientation?: keyof Orientation | OrientationNumber;
      maxDuration?: number;
      maxFileSize?: number;
      mute?: boolean;
      mirrorVideo?: boolean;
      path?: string;
      videoBitrate?: number;
    
      /** iOS only */
      codec?: keyof VideoCodec | VideoCodec[keyof VideoCodec];
    }

    RecordResponse:录制后的响应结果

    export interface RecordResponse {
      /** Path to the video saved on your app's cache directory. */
      uri: string;
      videoOrientation: number;
      deviceOrientation: number;
      isRecordingInterrupted: boolean;
      /** iOS only */
      codec: VideoCodec[keyof VideoCodec];
    }

    3、更多的介绍请查看完整文件,如下:

    // Type definitions for react-native-camera 1.0
    // Definitions by: Felipe Constantino <https://github.com/fconstant>
    //                 Trent Jones <https://github.com/FizzBuzz791>
    // If you modify this file, put your GitHub info here as well (for easy contacting purposes)
    
    /*
     * Author notes:
     * I've tried to find a easy tool to convert from Flow to Typescript definition files (.d.ts).
     * So we woudn't have to do it manually... Sadly, I haven't found it.
     *
     * If you are seeing this from the future, please, send us your cutting-edge technology :) (if it exists)
     */
    import { Component, ReactNode } from 'react';
    import { NativeMethodsMixinStatic, ViewProperties, findNodeHandle } from 'react-native';
    
    type Orientation = Readonly<{
      auto: any;
      landscapeLeft: any;
      landscapeRight: any;
      portrait: any;
      portraitUpsideDown: any;
    }>;
    type OrientationNumber = 1 | 2 | 3 | 4;
    type AutoFocus = Readonly<{ on: any; off: any }>;
    type FlashMode = Readonly<{ on: any; off: any; torch: any; auto: any }>;
    type CameraType = Readonly<{ front: any; back: any }>;
    type WhiteBalance = Readonly<{
      sunny: any;
      cloudy: any;
      shadow: any;
      incandescent: any;
      fluorescent: any;
      auto: any;
    }>;
    type BarCodeType = Readonly<{
      aztec: any;
      code128: any;
      code39: any;
      code39mod43: any;
      code93: any;
      ean13: any;
      ean8: any;
      pdf417: any;
      qr: any;
      upc_e: any;
      interleaved2of5: any;
      itf14: any;
      datamatrix: any;
    }>;
    type VideoQuality = Readonly<{
      '2160p': any;
      '1080p': any;
      '720p': any;
      '480p': any;
      '4:3': any;
      /** iOS Only. Android not supported. */
      '288p': any;
    }>;
    type VideoCodec = Readonly<{
      H264: symbol;
      JPEG: symbol;
      HVEC: symbol;
      AppleProRes422: symbol;
      AppleProRes4444: symbol;
    }>;
    
    type FaceDetectionClassifications = Readonly<{ all: any; none: any }>;
    type FaceDetectionLandmarks = Readonly<{ all: any; none: any }>;
    type FaceDetectionMode = Readonly<{ fast: any; accurate: any }>;
    type GoogleVisionBarcodeType = Readonly<{
      CODE_128: any;
      CODE_39: any;
      CODABAR: any;
      DATA_MATRIX: any;
      EAN_13: any;
      EAN_8: any;
      ITF: any;
      QR_CODE: any;
      UPC_A: any;
      UPC_E: any;
      PDF417: any;
      AZTEC: any;
      ALL: any;
    }>;
    type GoogleVisionBarcodeMode = Readonly<{ NORMAL: any; ALTERNATE: any; INVERTED: any }>;
    
    // FaCC (Function as Child Components)
    type Self<T> = { [P in keyof T]: P };
    type CameraStatus = Readonly<Self<{ READY: any; PENDING_AUTHORIZATION: any; NOT_AUTHORIZED: any }>>;
    type RecordAudioPermissionStatus = Readonly<
      Self<{
        AUTHORIZED: 'AUTHORIZED';
        PENDING_AUTHORIZATION: 'PENDING_AUTHORIZATION';
        NOT_AUTHORIZED: 'NOT_AUTHORIZED';
      }>
    >;
    type FaCC = (
      params: {
        camera: RNCamera;
        status: keyof CameraStatus;
        recordAudioPermissionStatus: keyof RecordAudioPermissionStatus;
      },
    ) => JSX.Element;
    
    export interface Constants {
      CameraStatus: CameraStatus;
      AutoFocus: AutoFocus;
      FlashMode: FlashMode;
      VideoCodec: VideoCodec;
      Type: CameraType;
      WhiteBalance: WhiteBalance;
      VideoQuality: VideoQuality;
      BarCodeType: BarCodeType;
      FaceDetection: {
        Classifications: FaceDetectionClassifications;
        Landmarks: FaceDetectionLandmarks;
        Mode: FaceDetectionMode;
      };
      GoogleVisionBarcodeDetection: {
        BarcodeType: GoogleVisionBarcodeType;
        BarcodeMode: GoogleVisionBarcodeMode;
      };
      Orientation: {
        auto: 'auto';
        landscapeLeft: 'landscapeLeft';
        landscapeRight: 'landscapeRight';
        portrait: 'portrait';
        portraitUpsideDown: 'portraitUpsideDown';
      };
    }
    
    export interface RNCameraProps {
      children?: ReactNode | FaCC;
    
      autoFocus?: keyof AutoFocus;
      autoFocusPointOfInterest?: Point;
      /* iOS only */
      onSubjectAreaChanged?: (event: { nativeEvent: { prevPoint: { x: number; y: number; } } }) => void;
      type?: keyof CameraType;
      flashMode?: keyof FlashMode;
      notAuthorizedView?: JSX.Element;
      pendingAuthorizationView?: JSX.Element;
      useCamera2Api?: boolean;
      exposure?: number;
      whiteBalance?: keyof WhiteBalance;
      captureAudio?: boolean;
    
      onCameraReady?(): void;
      onStatusChange?(event: {
        cameraStatus: keyof CameraStatus;
        recordAudioPermissionStatus: keyof RecordAudioPermissionStatus;
      }): void;
      onMountError?(error: { message: string }): void;
    
      /** iOS only */
      onAudioInterrupted?(): void;
      onAudioConnected?(): void;
    
      /** Value: float from 0 to 1.0 */
      zoom?: number;
      /** iOS only. float from 0 to any. Locks the max zoom value to the provided value
        A value <= 1 will use the camera's max zoom, while a value > 1
        will use that value as the max available zoom
      **/
      maxZoom?: number;
      /** Value: float from 0 to 1.0 */
      focusDepth?: number;
    
      // -- BARCODE PROPS
      barCodeTypes?: Array<keyof BarCodeType>;
      googleVisionBarcodeType?: Constants['GoogleVisionBarcodeDetection']['BarcodeType'];
      googleVisionBarcodeMode?: Constants['GoogleVisionBarcodeDetection']['BarcodeMode'];
      onBarCodeRead?(event: {
        data: string;
        rawData?: string;
        type: keyof BarCodeType;
        /**
         * @description For Android use `{  number, height: number, origin: Array<Point<string>> }`
         * @description For iOS use `{ origin: Point<string>, size: Size<string> }`
         */
        bounds: {  number, height: number, origin: Array<Point<string>> } | { origin: Point<string>; size: Size<string> };
      }): void;
    
      onGoogleVisionBarcodesDetected?(event: {
        barcodes: Barcode[];
      }): void;
    
      // -- FACE DETECTION PROPS
    
      onFacesDetected?(response: { faces: Face[] }): void;
      onFaceDetectionError?(response: { isOperational: boolean }): void;
      faceDetectionMode?: keyof FaceDetectionMode;
      faceDetectionLandmarks?: keyof FaceDetectionLandmarks;
      faceDetectionClassifications?: keyof FaceDetectionClassifications;
      trackingEnabled?: boolean;
    
      onTextRecognized?(response: { textBlocks: TrackedTextFeature[] }): void;
      // -- ANDROID ONLY PROPS
      /** Android only */
      ratio?: string;
      /** Android only - Deprecated */
      permissionDialogTitle?: string;
      /** Android only - Deprecated */
      permissionDialogMessage?: string;
      /** Android only */
      playSoundOnCapture?: boolean;
    
      androidCameraPermissionOptions?: {
        title: string;
        message: string;
        buttonPositive?: string;
        buttonNegative?: string;
        buttonNeutral?: string;
      } | null;
    
      androidRecordAudioPermissionOptions?: {
        title: string;
        message: string;
        buttonPositive?: string;
        buttonNegative?: string;
        buttonNeutral?: string;
      } | null;
    
      // -- IOS ONLY PROPS
      defaultVideoQuality?: keyof VideoQuality;
      /* if true, audio session will not be released on component unmount */
      keepAudioSession?: boolean;
    }
    
    interface Point<T = number> {
      x: T;
      y: T;
    }
    
    interface Size<T = number> {
       T;
      height: T;
    }
    
    export interface Barcode {
      bounds: {
        size: Size;
        origin: Point;
      };
      data: string;
      dataRaw: string;
      type: BarcodeType;
      format?: string;
      addresses?: {
        addressesType?: "UNKNOWN" | "Work" | "Home";
        addressLines?: string[];
      }[];
      emails?: Email[];
      phones?: Phone[];
      urls?: string[];
      name?: {
        firstName?: string;
        lastName?: string;
        middleName?: string;
        prefix?:string;
        pronounciation?:string;
        suffix?:string;
        formattedName?: string;
      };
      phone?: Phone;
      organization?: string;
      latitude?: number;
      longitude?: number;
      ssid?: string;
      password?: string;
      encryptionType?: string;
      title?: string;
      url?: string;
      firstName?: string;
      middleName?: string;
      lastName?: string;
      gender?: string;
      addressCity?: string;
      addressState?: string;
      addressStreet?: string;
      addressZip?: string;
      birthDate?: string;
      documentType?: string;
      licenseNumber?: string;
      expiryDate?: string;
      issuingDate?: string;
      issuingCountry?: string;
      eventDescription?: string;
      location?: string;
      organizer?: string;
      status?: string;
      summary?: string;
      start?: string;
      end?: string;
      email?: Email;
      phoneNumber?: string;
      message?: string;
    }
    
    export type BarcodeType =
      |"EMAIL"
      |"PHONE"
      |"CALENDAR_EVENT"
      |"DRIVER_LICENSE"
      |"GEO"
      |"SMS"
      |"CONTACT_INFO"
      |"WIFI"
      |"TEXT"
      |"ISBN"
      |"PRODUCT"
      |"URL"
    
    export interface Email {
      address?: string;
      body?: string;
      subject?: string;
      emailType?: "UNKNOWN" | "Work" | "Home";
    }
    
    export interface Phone {
      number?: string;
      phoneType?: "UNKNOWN" | "Work" | "Home" | "Fax" | "Mobile";
    }
    
    export interface Face {
      faceID?: number;
      bounds: {
        size: Size;
        origin: Point;
      };
      smilingProbability?: number;
      leftEarPosition?: Point;
      rightEarPosition?: Point;
      leftEyePosition?: Point;
      leftEyeOpenProbability?: number;
      rightEyePosition?: Point;
      rightEyeOpenProbability?: number;
      leftCheekPosition?: Point;
      rightCheekPosition?: Point;
      leftMouthPosition?: Point;
      mouthPosition?: Point;
      rightMouthPosition?: Point;
      bottomMouthPosition?: Point;
      noseBasePosition?: Point;
      yawAngle?: number;
      rollAngle?: number;
    }
    
    export interface TrackedTextFeature {
      type: 'block' | 'line' | 'element';
      bounds: {
        size: Size;
        origin: Point;
      };
      value: string;
      components: TrackedTextFeature[];
    }
    
    interface TakePictureOptions {
      quality?: number;
      orientation?: keyof Orientation | OrientationNumber;
      base64?: boolean;
      exif?: boolean;
      width?: number;
      mirrorImage?: boolean;
      doNotSave?: boolean;
      pauseAfterCapture?: boolean;
      writeExif?: boolean | { [name: string]: any };
    
      /** Android only */
      fixOrientation?: boolean;
    
      /** iOS only */
      forceUpOrientation?: boolean;
    }
    
    export interface TakePictureResponse {
       number;
      height: number;
      uri: string;
      base64?: string;
      exif?: { [name: string]: any };
      pictureOrientation: number;
      deviceOrientation: number;
    }
    
    interface RecordOptions {
      quality?: keyof VideoQuality;
      orientation?: keyof Orientation | OrientationNumber;
      maxDuration?: number;
      maxFileSize?: number;
      mute?: boolean;
      mirrorVideo?: boolean;
      path?: string;
      videoBitrate?: number;
    
      /** iOS only */
      codec?: keyof VideoCodec | VideoCodec[keyof VideoCodec];
    }
    
    export interface RecordResponse {
      /** Path to the video saved on your app's cache directory. */
      uri: string;
      videoOrientation: number;
      deviceOrientation: number;
      isRecordingInterrupted: boolean;
      /** iOS only */
      codec: VideoCodec[keyof VideoCodec];
    }
    
    export class RNCamera extends Component<RNCameraProps & ViewProperties> {
      static Constants: Constants;
    
      _cameraRef: null | NativeMethodsMixinStatic;
      _cameraHandle: ReturnType<typeof findNodeHandle>;
    
      takePictureAsync(options?: TakePictureOptions): Promise<TakePictureResponse>;
      recordAsync(options?: RecordOptions): Promise<RecordResponse>;
      refreshAuthorizationStatus(): Promise<void>;
      stopRecording(): void;
      pausePreview(): void;
      resumePreview(): void;
      getAvailablePictureSizes(): Promise<string[]>;
    
      /** Android only */
      getSupportedRatiosAsync(): Promise<string[]>;
    
      /** iOS only */
      isRecording(): Promise<boolean>;
    }
    
    interface DetectionOptions {
      mode?: keyof FaceDetectionMode;
      detectLandmarks?: keyof FaceDetectionLandmarks;
      runClassifications?: keyof FaceDetectionClassifications;
    }
    
    export class FaceDetector {
      private constructor();
      static Constants: Constants['FaceDetection'];
      static detectFacesAsync(uri: string, options?: DetectionOptions): Promise<Face[]>;
    }
    
    // -- DEPRECATED CONTENT BELOW
    
    /**
     * @deprecated As of 1.0.0 release, RCTCamera is deprecated. Please use RNCamera for the latest fixes and improvements.
     */
    export default class RCTCamera extends Component<any> {
      static constants: any;
    }
    View Code

    四、使用

    实现一个摄像头切换、扫描二维码功能。(模拟器无法调起相机)请使用真机测试。

    切记要添加授权字段:Privacy - Camera Usage Description、Privacy - Microphone Usage Description。代码示例如下:

    /**
     * Sample React Native App
     * https://github.com/facebook/react-native
     * @flow
     */
    
    import React, { Component } from 'react';
    
    import {
        AppRegistry,
        StyleSheet,
        Text,
        TouchableHighlight
    } from 'react-native';
    
    import {RNCamera, TakePictureResponse} from 'react-native-camera';
    
    export default class ReactNativeDemo extends Component {
    
        //设置当前摄像头为后置摄像头
        state = { cameraType: RNCamera.Constants.Type.back };
    
        //扫描二维码
        _onBarCodeRead(e){
            //data: string;
            //rawData?: string;
            //type: keyof BarCodeType;
            //bounds:
              //For iOS use `{ origin: Point<string>, size: Size<string> }`
              //For Android use `{  number, height: number, origin: Array<Point<string>> }`
            console.log(e)
        }
    
        //切换摄像头方向     undefined is not an object (evaluating 'state.cameraType')
        _switchCamera(){
            this.setState({
                cameraType: (this.state.cameraType === RNCamera.Constants.Type.back) ?
                    RNCamera.Constants.Type.front : RNCamera.Constants.Type.back
            })
            // let state = this.state;
            // state.cameraType = (state.cameraType === RNCamera.Constants.Type.back) ?
            //     RNCamera.Constants.Type.front : RNCamera.Constants.Type.back;
            // this.setState(state);
        }
    
        //拍摄照片
        _takePicture(){
            this.refs.camera.takePictureAsync().then( (response) => {
                console.log("response.uri:"+response.uri)
            }).catch((error => {
                console.log("error:"+error)
            }))
        }
    
        render() {
            return (
                <RNCamera
                    ref="camera"
                    style={styles.container}
                    onBarCodeRead={this._onBarCodeRead.bind(this)}
                    type={this.state.cameraType}
                >
                    <TouchableHighlight onPress={this._switchCamera.bind(this)}>
                        <Text style={styles.switch}>Switch Camera</Text>
                    </TouchableHighlight>
    
                    <TouchableHighlight onPress={this._takePicture.bind(this)}>
                        <Text style={styles.picture}>Take Picture</Text>
                    </TouchableHighlight>
                </RNCamera>
            );
        }
    }
    
    const styles = StyleSheet.create({
        container: {
            flex: 1,
            justifyContent: 'center',
            alignItems: 'center',
            backgroundColor: 'transparent'
        },
        switch: {
            marginTop: 30,
            textAlign: 'center',
            fontSize: 30,
            color: 'red'
        },
        picture: {
            marginTop: 30,
            textAlign: 'center',
            fontSize: 30,
            color: 'red'
        }
    });
    
    AppRegistry.registerComponent('ReactNativeDemo', () => ReactNativeDemo);

    模拟器运行出现,无法启动相机如下

                                                               

    真机运行出现,对相机和麦克风进行授权后,示例如下

     

    拍照时的打印日至如下:

    2020-01-11 10:52:23.940 [info][tid:com.facebook.react.JavaScript] response.uri:file:///var/mobile/Containers/Data/Application/F36A8D1A-2F96-4E24-B2D8-9755AD1FF488/Library/Caches/Camera/F4B30B4E-69C5-4D61-B2AE-99426AED52F2.jpg
  • 相关阅读:
    [C#]StringWriter实现的一个功能
    ASP.NET AJAX入门系列(1):概述
    ASP.NET 2.0 之 Master Page 学习笔记
    C#文件读写常用类介绍
    最新版FreeTextBox(版本3.1.6)在ASP.Net 2.0中使用简解
    关于Ajax 错误:'sys'未定义解决方法.
    教你解决微软MSN8.5无法安装问题
    对于javascript的function的总结
    ASP.NET开发:在用户控件中添加属性
    如何遍历枚举类型的对象、并获取枚举类型长度
  • 原文地址:https://www.cnblogs.com/XYQ-208910/p/12176757.html
Copyright © 2011-2022 走看看