HarmonyOS鸿蒙系统上，file文件常用操作记录

1.创建文件

 createFile(fileName: string, content: string): string {// 获取应用文件路径let context = getContext(this) as common.UIAbilityContext;let filesDirPath = context.filesDir + '/' + fileName;// 新建并打开文件let file = fs.openSync(filesDirPath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);// 写入一段内容至文件let writeLen = fs.writeSync(file.fd, content);// 从文件读取一段内容let buf = new ArrayBuffer(1024);let readLen = fs.readSync(file.fd, buf, { offset: 0 });// 关闭文件fs.closeSync(file);return filesDirPath}

2.将沙箱文件移动到分布式文件夹

 /*** 创建分布式文件*/async createDistributedFile(uri: string) {// 获取应用文件路径let context = getContext(this) as common.UIAbilityContext;let filesDir = context.distributedFilesDir;let fileName = this.getFileName(uri)try {let destUriPath = filesDir + '/' + fileNamethis.tempFilePath = fileName//给新建的文件写入内容// mMediaFileUtils.writeFileContent(destUriPath,content)// 新建并打开文件let writeFile = fs.openSync(destUriPath, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);//设置文件权限securityLabel.setSecurityLabel(destUriPath, 's1').then(() => {})// fs.write(file.fd,content)//读取原文件内容// 读取图片为bufferconst file = fs.openSync(uri, fs.OpenMode.READ_ONLY);let photoSize = fs.statSync(file.fd).size;let buffer = new ArrayBuffer(photoSize);fs.readSync(file.fd, buffer);fs.closeSync(file);//开始写入内容let writeLen = fs.write(writeFile.fd, buffer)} catch (error) {}}

3.读取分布式文件

  /*** 读取分布式文件* @param filePath*/readDistributedFile(filePath: string) {let context = getContext(this) as common.UIAbilityContext;let distributedFilesDir = context.distributedFilesDir;let distributedFilesDirs = fs.listFileSync(distributedFilesDir);for (let i = 0; i < distributedFilesDirs.length; i++) {let fileName = distributedFilesDir + '/' + distributedFilesDirs[i]this.readFile(fileName)}}

4.读取文件内容

  /*** 读取文件* @param filePath 文件路径*/readFile(filePath: string) {try {// 打开分布式目录下的文件let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE);// 定义接收读取数据的缓存let arrayBuffer = new ArrayBuffer(4096);// 读取文件的内容，返回值是读取到的字节个数class Option {public offset: number = 0;public length: number = 0;}let option = new Option();option.length = arrayBuffer.byteLength;let num = fs.readSync(file.fd, arrayBuffer, option);// 打印读取到的文件数据let buf = buffer.from(arrayBuffer, 0, num);Log.info('读取的文件内容: ' + buf.toString());} catch (error) {let err: BusinessError = error as BusinessError;Log.error(`Failed to openSync / readSync. Code: ${err.code}, message: ${err.message}`);}}

5.产看文件列表（沙箱和分布式文件夹）

  /*** 查看文件列表 沙箱文件夹 和 分布式文件夹*/lookFilesList(): string {//沙箱文件夹let allFiles = ''let context = getContext(this) as common.UIAbilityContext;let filesDir = context.filesDir;let files = fs.listFileSync(filesDir);for (let i = 0; i < files.length; i++) {Log.info(`当前设备文件 name: ${files[i]}`);}//分布式文件夹let distributedFilesDir = context.distributedFilesDir;Log.info('context.distributedFilesDir: ' + distributedFilesDir)let distributedFilesDirs = fs.listFileSync(distributedFilesDir);if (distributedFilesDirs.length > 0) {for (let i = 0; i < distributedFilesDirs.length; i++) {Log.info(`分布式文件 name: ${distributedFilesDirs[i]}`);}}return allFiles;}

6.删除分布式下指定文件

  /*** 删除分布式指定文件*/deleteDistributedFile(fileName: string) {let context = getContext(this) as common.UIAbilityContext;let filePath = context.distributedFilesDir + '/' + fileNamesecurityLabel.setSecurityLabel(filePath, 's1').then(() => {Log.info('Succeeded in setSecurityLabeling.');})try {fs.rmdir(filePath)Log.info('刪除文件成功')} catch (error) {let err: BusinessError = error as BusinessError;Log.error(`Failed to openSync / readSync. Code: ${err.code}, message: ${err.message}`);}}

7. 删除本地文件

  /*** 删除本地文件*/deleteCurrentDeviceFile() {let context = getContext(this) as common.UIAbilityContext;let filesDir = context.filesDir;let filesDirs = fs.listFileSync(filesDir);if (filesDirs.length <= 0) {return}let fileName = filesDirs + '/' + filesDirs[0]securityLabel.setSecurityLabel(fileName, 's1').then(() => {Log.info('Succeeded in setSecurityLabeling.');})try {fs.rmdir(fileName)Log.info('刪除文件成功')} catch (error) {let err: BusinessError = error as BusinessError;Log.error(`Failed to openSync / readSync. Code: ${err.code}, message: ${err.message}`);}}

8.获取文件名

  /*** 获取文件名* @param filePath* @returns*/getFileName(filePath: string): string {const parts = filePath.split('/');if (parts.length === 0) {return '';} // 如果没有找到任何斜杠，返回nullconst fileNameWithExtension = parts[parts.length - 1];const fileNameParts = fileNameWithExtension.split('.');if (fileNameParts.length < 2) {return fileNameWithExtension;} // 如果没有扩展名，直接返回文件名// return fileNameParts[0]; // 返回文件名（不含扩展名）return fileNameWithExtension; // 返回文件名,含扩展名}

9.保存文件到本地文件夹

 /*** 拉起picker保存文件*/async saveFile(fileName: string):Promise<string>{let saveFileUri = ''try {let DocumentSaveOptions = new picker.DocumentSaveOptions();DocumentSaveOptions.newFileNames = [fileName];let documentPicker = new picker.DocumentViewPicker();await documentPicker.save(DocumentSaveOptions).then( (DocumentSaveResult) => {if (DocumentSaveResult !== null && DocumentSaveResult !== undefined) {let uri = DocumentSaveResult[0] as string;this.realFileUri = urithis.realSaveFile(fileName)saveFileUri = uri}}).catch((err: BusinessError) => {Log.error('saveFile-DocumentViewPicker.save failed with err: ' + JSON.stringify(err));});} catch (err) {Log.error('saveFile-DocumentViewPicker failed with err: ' + err);}return saveFileUri}realFileUri: string = ''/*** 真正开始保存文件*/async realSaveFile(fileName: string) {let context = getContext(this) as common.UIAbilityContext;let pathDir = context.distributedFilesDir;// 获取分布式目录的文件路径let filePath = pathDir + '/' + fileName;// 读取bufferconst file = fs.openSync(filePath, fs.OpenMode.READ_ONLY);let photoSize = fs.statSync(file.fd).size;let buffer = new ArrayBuffer(photoSize);fs.readSync(file.fd, buffer);fs.closeSync(file);let saveFile = fs.openSync(this.realFileUri, fs.OpenMode.WRITE_ONLY);let writeLen = fs.write(saveFile.fd, buffer)Log.info(`save file uri success ~~~~~` + writeLen);//保存成功以后删除分布式上面的文件this.deleteDistributedFile(filePath)}