SharedPreferencesBackupHelper Class
Definition
Important
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A helper class that can be used in conjunction with
android.app.backup.BackupAgentHelper to manage the backup of
android.content.SharedPreferences.
[Android.Runtime.Register("android/app/backup/SharedPreferencesBackupHelper", DoNotGenerateAcw=true)]
public class SharedPreferencesBackupHelper : Android.App.Backup.FileBackupHelperBase, Android.App.Backup.IBackupHelper, IDisposable, Java.Interop.IJavaPeerable[<Android.Runtime.Register("android/app/backup/SharedPreferencesBackupHelper", DoNotGenerateAcw=true)>]
type SharedPreferencesBackupHelper = class
inherit FileBackupHelperBase
interface IBackupHelper
interface IJavaObject
interface IDisposable
interface IJavaPeerable- Inheritance
- Attributes
- Implements
Remarks
A helper class that can be used in conjunction with android.app.backup.BackupAgentHelper to manage the backup of android.content.SharedPreferences. Whenever a backup is performed, it will back up all named shared preferences that have changed since the last backup operation.
To use this class, the application's backup agent class should extend android.app.backup.BackupAgentHelper. Then, in the agent's BackupAgent#onCreate() method, an instance of this class should be allocated and installed as a backup/restore handler within the BackupAgentHelper framework. For example, an agent supporting backup and restore for an application with two groups of android.content.SharedPreferences data might look something like this:
import android.app.backup.BackupAgentHelper;
import android.app.backup.SharedPreferencesBackupHelper;
public class MyBackupAgent extends BackupAgentHelper {
// The names of the SharedPreferences groups that the application maintains. These
// are the same strings that are passed to {@link Context#getSharedPreferences(String, int)}.
static final String PREFS_DISPLAY = "displayprefs";
static final String PREFS_SCORES = "highscores";
// An arbitrary string used within the BackupAgentHelper implementation to
// identify the SharedPreferenceBackupHelper's data.
static final String MY_PREFS_BACKUP_KEY = "myprefs";
// Allocate a helper and install it.
public void onCreate() {
SharedPreferencesBackupHelper helper =
new SharedPreferencesBackupHelper(this, PREFS_DISPLAY, PREFS_SCORES);
addHelper(MY_PREFS_BACKUP_KEY, helper);
}
}
No further implementation is needed; the BackupAgentHelper mechanism automatically dispatches the BackupAgent#onBackup(android.os.ParcelFileDescriptor, BackupDataOutput, android.os.ParcelFileDescriptor) BackupAgent.onBackup() and BackupAgent#onRestore(BackupDataInput, int, android.os.ParcelFileDescriptor) BackupAgent.onRestore() callbacks to the SharedPreferencesBackupHelper as appropriate.
Java documentation for android.app.backup.SharedPreferencesBackupHelper.
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.
Constructors
| SharedPreferencesBackupHelper(Context, String[]) |
Construct a helper for backing up and restoring the
|
| SharedPreferencesBackupHelper(IntPtr, JniHandleOwnership) |
A constructor used when creating managed representations of JNI objects; called by the runtime. |
Properties
| Class |
Returns the runtime class of this |
| Handle |
The handle to the underlying Android instance. (Inherited from Object) |
| JniIdentityHashCode | (Inherited from Object) |
| JniPeerMembers | |
| PeerReference | (Inherited from Object) |
| ThresholdClass |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
| ThresholdType |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
Methods
| Clone() |
Creates and returns a copy of this object. (Inherited from Object) |
| Dispose() | (Inherited from Object) |
| Dispose(Boolean) | (Inherited from Object) |
| Equals(Object) |
Indicates whether some other object is "equal to" this one. (Inherited from Object) |
| GetHashCode() |
Returns a hash code value for the object. (Inherited from Object) |
| JavaFinalize() |
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Object) |
| Notify() |
Wakes up a single thread that is waiting on this object's monitor. (Inherited from Object) |
| NotifyAll() |
Wakes up all threads that are waiting on this object's monitor. (Inherited from Object) |
| PerformBackup(ParcelFileDescriptor, BackupDataOutput, ParcelFileDescriptor) |
Backs up the configured |
| RestoreEntity(BackupDataInputStream) |
Restores one entity from the restore data stream to its proper shared preferences file store. |
| SetHandle(IntPtr, JniHandleOwnership) |
Sets the Handle property. (Inherited from Object) |
| ToArray<T>() | (Inherited from Object) |
| ToString() |
Returns a string representation of the object. (Inherited from Object) |
| UnregisterFromRuntime() | (Inherited from Object) |
| Wait() |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>. (Inherited from Object) |
| Wait(Int64, Int32) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
| Wait(Int64) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
| WriteNewStateDescription(ParcelFileDescriptor) |
Called by BackupAgentHelper after a restore operation to write the backup state file corresponding to the data as processed by the helper. |
Explicit Interface Implementations
| IJavaPeerable.Disposed() | (Inherited from Object) |
| IJavaPeerable.DisposeUnlessReferenced() | (Inherited from Object) |
| IJavaPeerable.Finalized() | (Inherited from Object) |
| IJavaPeerable.JniManagedPeerState | (Inherited from Object) |
| IJavaPeerable.SetJniIdentityHashCode(Int32) | (Inherited from Object) |
| IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates) | (Inherited from Object) |
| IJavaPeerable.SetPeerReference(JniObjectReference) | (Inherited from Object) |
Extension Methods
| PerformBackupAsync(IBackupHelper, ParcelFileDescriptor, BackupDataOutput, ParcelFileDescriptor) | |
| JavaCast<TResult>(IJavaObject) |
Performs an Android runtime-checked type conversion. |
| JavaCast<TResult>(IJavaObject) | |
| GetJniTypeName(IJavaPeerable) | |