# 跨设备文件拷贝

分布式文件系统为应用提供了跨设备文件拷贝的能力，开发者可以通过@ohos.file.fs (文件管理)进行跨设备拷贝文件。例如：多设备数据流转的场景，设备组网互联之后，设备A上的应用可将沙箱文件拷贝到设备A的分布式目录下。设备B在粘贴时，从B设备的分布式目录下将文件拷贝到对应的沙箱文件中。

#### 开发步骤

1.  完成分布式组网。
    
    将需要跨设备访问的两个设备登录同一账号，保证设备蓝牙和Wi-Fi功能开启，蓝牙无需互连，Wi-Fi无需接入同一个局域网。
    
2.  授权分布式数据同步权限。
    
    分布式数据同步权限的授权方式为user\_grant，因此需要调用requestPermissionsFromUser接口，以动态弹窗的方式向用户申请授权。示例中的context的获取方式请参见获取UIAbility的上下文信息。
    
    ```
    import { common, abilityAccessCtrl } from '@kit.AbilityKit';
    import { BusinessError } from '@kit.BasicServicesKit';
    ```
    
    ```
    let atManager = abilityAccessCtrl.createAtManager();
    try {
      // 以动态弹窗的方式向用户申请授权
      atManager.requestPermissionsFromUser(context, ['ohos.permission.DISTRIBUTED_DATASYNC']).then((result) => {
        console.info(`request permission result: ${JSON.stringify(result)}`);
      }).catch((err: BusinessError) => {
        console.error(`Failed to request permissions from user. Code: ${err.code}, message: ${err.message}`);
      })
    } catch (error) {
      let err: BusinessError = error as BusinessError;
      console.error(`Catch err. Failed to request permissions from user. Code: ${err.code}, message: ${err.message}`);
    }
    ```
    
3.  执行跨设备文件拷贝操作。
    
    同一应用在不同设备之间实现跨设备文件拷贝，只需要将对应的文件放在应用沙箱的分布式目录即可。
    
    将A设备的待拷贝沙箱文件拷贝到A设备的分布式目录下。
    
    ```
    import { fileIo } from '@kit.CoreFileKit';
    import { common } from '@kit.AbilityKit';
    import { BusinessError } from '@kit.BasicServicesKit';
    import { fileUri } from '@kit.CoreFileKit';
    ```
    
    ```
    let pathDir: string = context.filesDir;
    let distributedPathDir: string = context.distributedFilesDir;
    // 待拷贝文件沙箱路径
    let filePath: string = pathDir + '/src.txt';
    try {
      // 准备待拷贝沙箱文件
      let file = fileIo.openSync(filePath, fileIo.OpenMode.CREATE | fileIo.OpenMode.READ_WRITE);
      fileIo.writeSync(file.fd, 'Create file success');
      fileIo.closeSync(file);
    } catch (error) {
      console.error(`Failed to createFile. Code: ${error.code}, message: ${error.message}`);
    }
    
    // 获取待拷贝源文件uri
    let srcUri = fileUri.getUriFromPath(filePath);
    // 获取目标路径(分布式目录)的uri
    let destUri: string = fileUri.getUriFromPath(distributedPathDir + '/src.txt');
    try {
      // 将沙箱路径下的源文件拷贝到目标分布式目录下
      fileIo.copy(srcUri, destUri).then(()=>{
        console.info(`Succeeded in copying---. `);
        console.info(`src: ${srcUri} dest: ${destUri}`);
      }).catch((error: BusinessError)=>{
        let err: BusinessError = error as BusinessError;
        console.error(`Failed to copy. Code: ${err.code}, message: ${err.message}`);
      })
    } catch (error) {
      console.error(`Catch err. Failed to copy. Code: ${error.code}, message: ${error.message}`);
    }
    ```
    
    B设备在获取A设备沙箱文件时，从B设备的分布式目录下将对应的文件拷贝走，以此完成跨设备拷贝。
    
    ```
    import { fileIo } from '@kit.CoreFileKit';
    import { common } from '@kit.AbilityKit';
    import { BusinessError } from '@kit.BasicServicesKit';
    import { fileUri } from '@kit.CoreFileKit';
    import { distributedDeviceManager } from '@kit.DistributedServiceKit';
    ```
    
    ```
    // ...
    try {
      let pathDir: string = context.filesDir;
      let distributedPathDir: string = context.distributedFilesDir;
      // 待拷贝文件的目标路径(沙箱路径)
      let destPath: string = pathDir + '/dest.txt';
      // 获取目标路径uri
      let destUri = fileUri.getUriFromPath(destPath);
      
      // 拷贝源文件路径(分布式目录)
      let srcPath = distributedPathDir + '/src.txt';
      // 获取源路径uri
      let srcUri: string = fileUri.getUriFromPath(srcPath);
      
      // 定义拷贝回调
      let progressListener: fileIo.ProgressListener = (progress: fileIo.Progress) => {
        console.info(`progressSize: ${progress.processedSize}, totalSize: ${progress.totalSize}`);
      };
      let options: fileIo.CopyOptions = {
        'progressListener' : progressListener
      };
      // 通过分布式设备管理的接口获取设备A的networkId信息
      let dmInstance = distributedDeviceManager.createDeviceManager('com.example.hap');
      let deviceInfoList: distributedDeviceManager.DeviceBasicInfo[] = dmInstance.getAvailableDeviceListSync();
      if (deviceInfoList && deviceInfoList.length > 0) {
        console.info(`success to get available device list`);
        let networkId = deviceInfoList[0].networkId; // 这里只是两个设备连接，列表中首个即为A设备的networkId
        // 定义访问分布式目录的回调
        let listeners : fileIo.DfsListeners = {
          onStatus: (networkId: string, status: number): void => {
            console.error(`Failed to access public directory, ${status}`);
          }
        };
        // 开始跨设备文件拷贝
        fileIo.connectDfs(networkId, listeners).then(()=>{
          try {
            // 将分布式目录下的文件拷贝到其他沙箱路径下
            fileIo.copy(srcUri, destUri, options).then(()=>{
              console.info(`Succeeded in copying from distributed path`);
              console.info(`src: ${srcUri} dest: ${destUri}`);
              fileIo.unlinkSync(srcPath); // 拷贝完成后清理分布式目录下的临时文件
            }).catch((error: BusinessError)=>{
              let err: BusinessError = error as BusinessError;
              console.error(`Failed to copy. Code: ${err.code}, message: ${err.message}`);
            })
          } catch (error) {
            console.error(`Catch err. Failed to copy. Code: ${error.code}, message: ${error.message}`);
          }
        }).catch((error: BusinessError) => {
          let err: BusinessError = error as BusinessError;
          console.error(`Failed to connect dfs. Code: ${err.code}, message: ${err.message}`);
        });
      }
    } catch (error) {
      console.error(`Catch err. Code: ${error.code}, message: ${error.message}`);
    }
    ```
    
4.  跨设备文件拷贝完成，断开链路。
    
    ```
    import { BusinessError } from '@kit.BasicServicesKit';
    import { distributedDeviceManager } from '@kit.DistributedServiceKit'
    import { fileIo } from '@kit.CoreFileKit';
    ```
    
    ```
    // 获取设备A的networkId
    // ...
    try {
      let dmInstance = distributedDeviceManager.createDeviceManager('com.example.hap');
      let deviceInfoList: distributedDeviceManager.DeviceBasicInfo[] = dmInstance.getAvailableDeviceListSync();
      if (deviceInfoList && deviceInfoList.length > 0) {
        console.info(`Success to get available device list`);
        let networkId = deviceInfoList[0].networkId;
        // 关闭跨设备文件访问
        fileIo.disconnectDfs(networkId).then(() => {
          console.info(`Success to disconnect dfs`);
        }).catch((err: BusinessError) => {
          console.error(`Failed to disconnect dfs. Code: ${err.code}, message: ${err.message}`);
        })
      }
    } catch (error) {
      console.error(`Catch err. Code: ${error.code}, message: ${error.message}`);
    }
    ```