AsyncQueryHandler
public
abstract
class
AsyncQueryHandler
extends Handler
java.lang.Object | ||
↳ | android.os.Handler | |
↳ | android.content.AsyncQueryHandler |
A helper class to help make handling asynchronous ContentResolver
queries easier.
Summary
Nested classes | |
---|---|
class |
AsyncQueryHandler.WorkerArgs
|
class |
AsyncQueryHandler.WorkerHandler
|
Public constructors | |
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AsyncQueryHandler(ContentResolver cr)
|
Public methods | |
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final
void
|
cancelOperation(int token)
Attempts to cancel operation that has not already started. |
void
|
handleMessage(Message msg)
Subclasses must implement this to receive messages. |
final
void
|
startDelete(int token, Object cookie, Uri uri, String selection, String[] selectionArgs)
This method begins an asynchronous delete. |
final
void
|
startInsert(int token, Object cookie, Uri uri, ContentValues initialValues)
This method begins an asynchronous insert. |
void
|
startQuery(int token, Object cookie, Uri uri, String[] projection, String selection, String[] selectionArgs, String orderBy)
This method begins an asynchronous query. |
final
void
|
startUpdate(int token, Object cookie, Uri uri, ContentValues values, String selection, String[] selectionArgs)
This method begins an asynchronous update. |
Protected methods | |
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Handler
|
createHandler(Looper looper)
|
void
|
onDeleteComplete(int token, Object cookie, int result)
Called when an asynchronous delete is completed. |
void
|
onInsertComplete(int token, Object cookie, Uri uri)
Called when an asynchronous insert is completed. |
void
|
onQueryComplete(int token, Object cookie, Cursor cursor)
Called when an asynchronous query is completed. |
void
|
onUpdateComplete(int token, Object cookie, int result)
Called when an asynchronous update is completed. |
Inherited methods | |
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Public constructors
AsyncQueryHandler
public AsyncQueryHandler (ContentResolver cr)
Parameters | |
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cr |
ContentResolver |
Public methods
cancelOperation
public final void cancelOperation (int token)
Attempts to cancel operation that has not already started. Note that there is no guarantee that the operation will be canceled. They still may result in a call to on[Query/Insert/Update/Delete]Complete after this call has completed.
Parameters | |
---|---|
token |
int : The token representing the operation to be canceled.
If multiple operations have the same token they will all be canceled. |
handleMessage
public void handleMessage (Message msg)
Subclasses must implement this to receive messages.
Parameters | |
---|---|
msg |
Message : This value cannot be null . |
startDelete
public final void startDelete (int token, Object cookie, Uri uri, String selection, String[] selectionArgs)
This method begins an asynchronous delete. When the delete operation is
done onDeleteComplete(int, Object, int)
is called.
Parameters | |
---|---|
token |
int : A token passed into onDeleteComplete(int, Object, int) to identify
the delete operation. |
cookie |
Object : An object that gets passed into onDeleteComplete(int, Object, int) |
uri |
Uri : the Uri passed to the delete operation. |
selection |
String : the where clause. |
selectionArgs |
String |
startInsert
public final void startInsert (int token, Object cookie, Uri uri, ContentValues initialValues)
This method begins an asynchronous insert. When the insert operation is
done onInsertComplete(int, Object, Uri)
is called.
Parameters | |
---|---|
token |
int : A token passed into onInsertComplete(int, Object, Uri) to identify
the insert operation. |
cookie |
Object : An object that gets passed into onInsertComplete(int, Object, Uri) |
uri |
Uri : the Uri passed to the insert operation. |
initialValues |
ContentValues : the ContentValues parameter passed to the insert operation. |
startQuery
public void startQuery (int token, Object cookie, Uri uri, String[] projection, String selection, String[] selectionArgs, String orderBy)
This method begins an asynchronous query. When the query is done
onQueryComplete(int, Object, Cursor)
is called.
Parameters | |
---|---|
token |
int : A token passed into onQueryComplete(int, Object, Cursor) to identify
the query. |
cookie |
Object : An object that gets passed into onQueryComplete(int, Object, Cursor) |
uri |
Uri : The URI, using the content:// scheme, for the content to
retrieve. |
projection |
String : A list of which columns to return. Passing null will
return all columns, which is discouraged to prevent reading data
from storage that isn't going to be used. |
selection |
String : A filter declaring which rows to return, formatted as an
SQL WHERE clause (excluding the WHERE itself). Passing null will
return all rows for the given URI. |
selectionArgs |
String : You may include ?s in selection, which will be
replaced by the values from selectionArgs, in the order that they
appear in the selection. The values will be bound as Strings. |
orderBy |
String : How to order the rows, formatted as an SQL ORDER BY
clause (excluding the ORDER BY itself). Passing null will use the
default sort order, which may be unordered. |
startUpdate
public final void startUpdate (int token, Object cookie, Uri uri, ContentValues values, String selection, String[] selectionArgs)
This method begins an asynchronous update. When the update operation is
done onUpdateComplete(int, Object, int)
is called.
Parameters | |
---|---|
token |
int : A token passed into onUpdateComplete(int, Object, int) to identify
the update operation. |
cookie |
Object : An object that gets passed into onUpdateComplete(int, Object, int) |
uri |
Uri : the Uri passed to the update operation. |
values |
ContentValues : the ContentValues parameter passed to the update operation. |
selection |
String |
selectionArgs |
String |
Protected methods
createHandler
protected Handler createHandler (Looper looper)
Parameters | |
---|---|
looper |
Looper |
Returns | |
---|---|
Handler |
onDeleteComplete
protected void onDeleteComplete (int token, Object cookie, int result)
Called when an asynchronous delete is completed.
Parameters | |
---|---|
token |
int : the token to identify the query, passed in from
startDelete(int, Object, Uri, String, String) . |
cookie |
Object : the cookie object that's passed in from
startDelete(int, Object, Uri, String, String) . |
result |
int : the result returned from the delete operation |
onInsertComplete
protected void onInsertComplete (int token, Object cookie, Uri uri)
Called when an asynchronous insert is completed.
Parameters | |
---|---|
token |
int : the token to identify the query, passed in from
startInsert(int, Object, Uri, ContentValues) . |
cookie |
Object : the cookie object that's passed in from
startInsert(int, Object, Uri, ContentValues) . |
uri |
Uri : the uri returned from the insert operation. |
onQueryComplete
protected void onQueryComplete (int token, Object cookie, Cursor cursor)
Called when an asynchronous query is completed.
Parameters | |
---|---|
token |
int : the token to identify the query, passed in from
startQuery(int, Object, Uri, String, String, String, String) . |
cookie |
Object : the cookie object passed in from startQuery(int, Object, Uri, String, String, String, String) . |
cursor |
Cursor : The cursor holding the results from the query. |
onUpdateComplete
protected void onUpdateComplete (int token, Object cookie, int result)
Called when an asynchronous update is completed.
Parameters | |
---|---|
token |
int : the token to identify the query, passed in from
startUpdate(int, Object, Uri, ContentValues, String, String) . |
cookie |
Object : the cookie object that's passed in from
startUpdate(int, Object, Uri, ContentValues, String, String) . |
result |
int : the result returned from the update operation |
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Last updated 2024-04-04 UTC.