HarmonyOS应用开发实战 - Api9 拍照、拍视频、选择图片、选择视频、选择文件工具类

鸿蒙开发过程中，经常会进行系统调用，拍照、拍视频、选择图库图片、选择图库视频、选择文件。今天就给大家分享一个工具类。

1.话不多说，先展示样式

在这里插入图片描述

2.设计思路

根据官方提供的指南开发工具类，基础的拍照、拍视频、图库选照片、选文件不过多缀述，图库选择这里设计成集合形式，可返回图片和视频，视频展示时不显示内容，所以在工具类多加了一个获取视频缩略图的功能。

3.具体代码

import common from '@ohos.app.ability.common';
import picker from '@ohos.file.picker';
import mediaLibrary from '@ohos.multimedia.mediaLibrary';
import wantConstant from '@ohos.ability.wantConstant';
import { MediaBean } from '../bean/MediaBean';
import { StringUtils } from '../utils/StringUtils';/*** @description 多媒体辅助类* @author Gwei* @time 2024/3/1 15:57*/
export class MediaHelper {private readonly TAG: string = 'MediaHelper';private mContext: common.Context;constructor(context: common.Context) {this.mContext = context;}/*** 图库选择,返回最大数量为9的图片、视频集合*/public selectPicture(count:number): Promise<Array<MediaBean>> {let imgList:Array<string> = [];let mediaList:Array<MediaBean> = [];try {let photoSelectOptions = new picker.PhotoSelectOptions();photoSelectOptions.MIMEType = picker.PhotoViewMIMETypes.IMAGE_TYPE;photoSelectOptions.maxSelectNumber = 9-count;let photoPicker = new picker.PhotoViewPicker();return photoPicker.select(photoSelectOptions).then((photoSelectResult) => {//Log.info(this.TAG, 'PhotoViewPicker.select successfully, PhotoSelectResult uri: ' + JSON.stringify(photoSelectResult));if (photoSelectResult && photoSelectResult.photoUris && photoSelectResult.photoUris.length > 0) {for (let i = 0; i < photoSelectResult.photoUris.length; i++) {imgList.push(photoSelectResult.photoUris[i]);}//Log.info(this.TAG, 'PhotoViewPicker.select successfully, PhotoSelectResult uri: ' + filePath);return imgList;}}).catch((err) => {//Log.error(this.TAG, 'PhotoViewPicker.select failed with err: ' + err);return err;}).then(async (imgList) => {for (let index = 0; index < imgList.length; index++) {const mediaBean = await this.buildMediaBean(imgList[index]);mediaList.push(mediaBean);}return mediaList;});} catch (err) {//Log.error(this.TAG, 'PhotoViewPicker failed with err: ' + err);return Promise.reject(err);}}/*** 选择文件*/public selectFile(): Promise<MediaBean> {try {let documentSelectOptions = new picker.DocumentSelectOptions();let documentPicker = new picker.DocumentViewPicker();return documentPicker.select(documentSelectOptions).then((documentSelectResult) => {//Log.info(this.TAG, 'DocumentViewPicker.select successfully, DocumentSelectResult uri: ' + JSON.stringify(documentSelectResult));if (documentSelectResult && documentSelectResult.length > 0) {let filePath = documentSelectResult[0];//Log.info(this.TAG, 'DocumentViewPicker.select successfully, DocumentSelectResult uri: ' + filePath);return filePath;}}).catch((err) => {//Log.error(this.TAG, 'PhotoViewPicker.select failed with err: ' + err);return err;}).then(async (filePath) => {const mediaBean = await this.buildMediaBean(filePath);return mediaBean;});} catch (err) {//Log.error(this.TAG, 'PhotoViewPicker failed with err: ' + err);return Promise.reject(err);}}/*** 拍照*/public async takePhoto(context: common.UIAbilityContext): Promise<MediaBean> {let want = {'uri': '','action': wantConstant.Action.ACTION_IMAGE_CAPTURE,'parameters': {},};return context.startAbilityForResult(want).then((result) => {//Log.info(this.TAG, `startAbility call back , ${JSON.stringify(result)}`);if (result.resultCode === 0 && result.want && StringUtils.isNotNullOrEmpty(result.want.uri)) {//拍照成功//Log.info(this.TAG, 'takePhoto successfully, takePhotoResult uri: ' + result.want.uri);return result.want.uri;}}).catch((error) => {//Log.info(this.TAG, `startAbility error , ${JSON.stringify(error)}`);return error;}).then(async (uri: string) => {const mediaBean = await this.buildMediaBean(uri);return mediaBean;});}/*** 拍视频*/public async takeVideo(context: common.UIAbilityContext): Promise<MediaBean> {let want = {'uri': '','action': wantConstant.Action.ACTION_VIDEO_CAPTURE,'parameters': {},};return context.startAbilityForResult(want).then((result) => {//Log.info(this.TAG, `startAbility call back , ${JSON.stringify(result)}`);if (result.resultCode === 0 && result.want && StringUtils.isNotNullOrEmpty(result.want.uri)) {//拍照成功//Log.info(this.TAG, 'takePhoto successfully, takePhotoResult uri: ' + result.want.uri);return result.want.uri;}}).catch((error) => {//Log.info(this.TAG, `startAbility error , ${JSON.stringify(error)}`);return error;}).then(async (uri: string) => {const mediaBean = await this.buildMediaBean(uri);return mediaBean;});}/*** 封装多媒体实体类** @param uri 文件路径*/private async buildMediaBean(uri: string): Promise<MediaBean> {if (StringUtils.isNullOrEmpty(uri)) {return null;}const mediaBean: MediaBean = new MediaBean();mediaBean.localUrl = uri;await this.appendFileInfoToMediaBean(mediaBean, uri);return mediaBean;}/*** 通过Uri查找所选文件信息，插入到MediaBean中* @param mediaBean* @param uri*/private async appendFileInfoToMediaBean(mediaBean: MediaBean, uri: string):Promise<MediaBean> {if (StringUtils.isNullOrEmpty(uri)) {return;}let fileList: Array<mediaLibrary.FileAsset> = [];const parts: string[] = uri.split('/');const id: string = parts.length > 0 ? parts[parts.length - 1] : '-1';try {let media = mediaLibrary.getMediaLibrary(this.mContext);let mediaFetchOptions: mediaLibrary.MediaFetchOptions = {selections: mediaLibrary.FileKey.ID + '= ?',selectionArgs: [id],uri: uri};let fetchFileResult = await media.getFileAssets(mediaFetchOptions);//Log.info(this.TAG, `fileList getFileAssetsFromType fetchFileResult.count = ${fetchFileResult.getCount()}`);fileList = await fetchFileResult.getAllObject();fetchFileResult.close();await media.release();} catch (e) {//Log.error(this.TAG, "query: file data  exception ");}if (fileList && fileList.length > 0) {let fileInfoObj = fileList[0];//Log.info(this.TAG, `file id = ${JSON.stringify(fileInfoObj.id)} , uri = ${JSON.stringify(fileInfoObj.uri)}`);//Log.info(this.TAG, `file fileList displayName = ${fileInfoObj.displayName} ,size = ${fileInfoObj.size} ,mimeType = ${fileInfoObj.mimeType}`);mediaBean.fileName = fileInfoObj.displayName;mediaBean.fileSize = fileInfoObj.size;mediaBean.fileType = fileInfoObj.mimeType;mediaBean.pixelmap = await this.getPixelmap(fileInfoObj)}}/*** @description 获取缩略图* @author Gwei* @time 2024/3/1 15:57*/getPixelmap(fileInfoObj) {return new Promise(function (resolve, reject) {fileInfoObj.getThumbnail((err, pixelmap) => {if (!err) {resolve(pixelmap)}else{resolve('');}})})}
}

4.使用方法

async handleClick(option: MediaOption) {let mediaBean: MediaBean;switch (option) {case MediaOption.TakePhoto:mediaBean = await this.mediaHelper.takePhoto(getContext() as common.UIAbilityContext);this.imgList.push(mediaBean)break;case MediaOption.TakeVideo:mediaBean = await this.mediaHelper.takeVideo(getContext() as common.UIAbilityContext);this.imgList.push(mediaBean)break;case MediaOption.Picture:let list: Array<MediaBean> = [];list = await this.mediaHelper.selectPicture(this.imgList.length);for (let i = 0; i < list.length; i++) {this.imgList.push(list[i])}break;case MediaOption.File:mediaBean = await this.mediaHelper.selectFile();this.audioList.push(mediaBean);break;default:break;}
}