DocumentsProvider.QueryChildDocuments Method
Definition
Important
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Overloads
QueryChildDocuments(String, String[], Bundle) |
Override this method to return the children documents contained in the requested directory. |
QueryChildDocuments(String, String[], String) |
Return the children documents contained in the requested directory. |
QueryChildDocuments(String, String[], Bundle)
Override this method to return the children documents contained in the requested directory.
[Android.Runtime.Register("queryChildDocuments", "(Ljava/lang/String;[Ljava/lang/String;Landroid/os/Bundle;)Landroid/database/Cursor;", "GetQueryChildDocuments_Ljava_lang_String_arrayLjava_lang_String_Landroid_os_Bundle_Handler", ApiSince=26)]
public virtual Android.Database.ICursor? QueryChildDocuments (string? parentDocumentId, string[]? projection, Android.OS.Bundle? queryArgs);
[<Android.Runtime.Register("queryChildDocuments", "(Ljava/lang/String;[Ljava/lang/String;Landroid/os/Bundle;)Landroid/database/Cursor;", "GetQueryChildDocuments_Ljava_lang_String_arrayLjava_lang_String_Landroid_os_Bundle_Handler", ApiSince=26)>]
abstract member QueryChildDocuments : string * string[] * Android.OS.Bundle -> Android.Database.ICursor
override this.QueryChildDocuments : string * string[] * Android.OS.Bundle -> Android.Database.ICursor
Parameters
- parentDocumentId
- String
the directory to return children for.
- projection
- String[]
list of Document
columns to put into the
cursor. If null
all supported columns should be
included.
- queryArgs
- Bundle
Bundle containing sorting information or other
argument useful to the provider. If no sorting
information is available, default sorting
will be used, which may be unordered. See
ContentResolver#QUERY_ARG_SORT_COLUMNS
for
details.
Returns
- Attributes
Remarks
Override this method to return the children documents contained in the requested directory. This must return immediate descendants only.
If your provider is cloud-based, and you have data cached locally, you may return the local data immediately, setting DocumentsContract#EXTRA_LOADING
on Cursor extras to indicate that you are still fetching additional data. Then, when the network data is available, you can send a change notification to trigger a requery and return the complete contents. To return a Cursor with extras, you need to extend and override Cursor#getExtras()
.
To support change notifications, you must Cursor#setNotificationUri(ContentResolver, Uri)
with a relevant Uri, such as DocumentsContract#buildChildDocumentsUri(String, String)
. Then you can call ContentResolver#notifyChange(Uri, android.database.ContentObserver, boolean)
with that Uri to send change notifications.
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.
Applies to
QueryChildDocuments(String, String[], String)
Return the children documents contained in the requested directory.
[Android.Runtime.Register("queryChildDocuments", "(Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;)Landroid/database/Cursor;", "GetQueryChildDocuments_Ljava_lang_String_arrayLjava_lang_String_Ljava_lang_String_Handler")]
public abstract Android.Database.ICursor? QueryChildDocuments (string? parentDocumentId, string[]? projection, string? sortOrder);
[<Android.Runtime.Register("queryChildDocuments", "(Ljava/lang/String;[Ljava/lang/String;Ljava/lang/String;)Landroid/database/Cursor;", "GetQueryChildDocuments_Ljava_lang_String_arrayLjava_lang_String_Ljava_lang_String_Handler")>]
abstract member QueryChildDocuments : string * string[] * string -> Android.Database.ICursor
Parameters
- parentDocumentId
- String
the directory to return children for.
- projection
- String[]
list of Document
columns to put into the
cursor. If null
all supported columns should be
included.
- sortOrder
- 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. This ordering is a hint that can be used to
prioritize how data is fetched from the network, but UI may
always enforce a specific ordering.
Returns
- Attributes
Exceptions
Remarks
Return the children documents contained in the requested directory. This must only return immediate descendants, as additional queries will be issued to recursively explore the tree.
Apps targeting android.os.Build.VERSION_CODES#O
or higher should override #queryChildDocuments(String, String[], Bundle)
.
If your provider is cloud-based, and you have some data cached or pinned locally, you may return the local data immediately, setting DocumentsContract#EXTRA_LOADING
on the Cursor to indicate that you are still fetching additional data. Then, when the network data is available, you can send a change notification to trigger a requery and return the complete contents. To return a Cursor with extras, you need to extend and override Cursor#getExtras()
.
To support change notifications, you must Cursor#setNotificationUri(ContentResolver, Uri)
with a relevant Uri, such as DocumentsContract#buildChildDocumentsUri(String, String)
. Then you can call ContentResolver#notifyChange(Uri, android.database.ContentObserver, boolean)
with that Uri to send change notifications.
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.