FileBackupHelper.PerformBackup Method
Definition
Important
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Based on oldState
, determine which of the files from the
application's data directory need to be backed up, write them to the data
stream, and fill in newState
with the state as it exists
now.
[Android.Runtime.Register("performBackup", "(Landroid/os/ParcelFileDescriptor;Landroid/app/backup/BackupDataOutput;Landroid/os/ParcelFileDescriptor;)V", "GetPerformBackup_Landroid_os_ParcelFileDescriptor_Landroid_app_backup_BackupDataOutput_Landroid_os_ParcelFileDescriptor_Handler")]
public virtual void PerformBackup (Android.OS.ParcelFileDescriptor? oldState, Android.App.Backup.BackupDataOutput? data, Android.OS.ParcelFileDescriptor? newState);
[<Android.Runtime.Register("performBackup", "(Landroid/os/ParcelFileDescriptor;Landroid/app/backup/BackupDataOutput;Landroid/os/ParcelFileDescriptor;)V", "GetPerformBackup_Landroid_os_ParcelFileDescriptor_Landroid_app_backup_BackupDataOutput_Landroid_os_ParcelFileDescriptor_Handler")>]
abstract member PerformBackup : Android.OS.ParcelFileDescriptor * Android.App.Backup.BackupDataOutput * Android.OS.ParcelFileDescriptor -> unit
override this.PerformBackup : Android.OS.ParcelFileDescriptor * Android.App.Backup.BackupDataOutput * Android.OS.ParcelFileDescriptor -> unit
Parameters
- oldState
- ParcelFileDescriptor
An open, read-only ParcelFileDescriptor pointing to the
last backup state provided by the application. May be
null
, in which case no prior state is being
provided and the application should perform a full backup.
- data
- BackupDataOutput
An open, read/write BackupDataOutput pointing to the backup data destination. Typically the application will use backup helper classes to write to this file.
- newState
- ParcelFileDescriptor
An open, read/write ParcelFileDescriptor pointing to an
empty file. The application should record the final backup
state here after writing the requested data to the data
output stream.
Implements
- Attributes
Remarks
Based on oldState
, determine which of the files from the application's data directory need to be backed up, write them to the data stream, and fill in newState
with the state as it exists now. When oldState
is null
, all the files will be backed up.
This should only be called directly from within the BackupAgentHelper
implementation. See android.app.backup.BackupAgent#onBackup(ParcelFileDescriptor, BackupDataOutput, ParcelFileDescriptor)
for a description of parameter meanings.
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.