Partager via


DocumentsProvider.OpenDocumentThumbnail Method

Definition

Open and return a thumbnail of the requested document.

[Android.Runtime.Register("openDocumentThumbnail", "(Ljava/lang/String;Landroid/graphics/Point;Landroid/os/CancellationSignal;)Landroid/content/res/AssetFileDescriptor;", "GetOpenDocumentThumbnail_Ljava_lang_String_Landroid_graphics_Point_Landroid_os_CancellationSignal_Handler")]
public virtual Android.Content.Res.AssetFileDescriptor? OpenDocumentThumbnail (string? documentId, Android.Graphics.Point? sizeHint, Android.OS.CancellationSignal? signal);
[<Android.Runtime.Register("openDocumentThumbnail", "(Ljava/lang/String;Landroid/graphics/Point;Landroid/os/CancellationSignal;)Landroid/content/res/AssetFileDescriptor;", "GetOpenDocumentThumbnail_Ljava_lang_String_Landroid_graphics_Point_Landroid_os_CancellationSignal_Handler")>]
abstract member OpenDocumentThumbnail : string * Android.Graphics.Point * Android.OS.CancellationSignal -> Android.Content.Res.AssetFileDescriptor
override this.OpenDocumentThumbnail : string * Android.Graphics.Point * Android.OS.CancellationSignal -> Android.Content.Res.AssetFileDescriptor

Parameters

documentId
String

the document to return.

sizeHint
Point

hint of the optimal thumbnail dimensions.

signal
CancellationSignal

used by the caller to signal if the request should be cancelled. May be null.

Returns

Attributes

Exceptions

Remarks

Open and return a thumbnail of the requested document.

A provider should return a thumbnail closely matching the hinted size, attempting to serve from a local cache if possible. A provider should never return images more than double the hinted size.

If you perform expensive operations to download or generate a thumbnail, you should periodically check CancellationSignal#isCanceled() to abort abandoned thumbnail requests.

Java documentation for android.provider.DocumentsProvider.openDocumentThumbnail(java.lang.String, android.graphics.Point, android.os.CancellationSignal).

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