StorageVolume
class StorageVolume : Parcelable
kotlin.Any | |
↳ | android.os.storage.StorageVolume |
Information about a shared/external storage volume for a specific user.
A device always has one (and one only) primary storage volume, but it could have extra volumes, like SD cards and USB drives. This object represents the logical view of a storage volume for a specific user: different users might have different views for the same physical volume (for example, if the volume is a built-in emulated storage).
The storage volume is not necessarily mounted, applications should use getState()
to verify its state.
Applications willing to read or write to this storage volume needs to get a permission from the user first, which can be achieved in the following ways:
- To get access to standard directories (like the
Environment#DIRECTORY_PICTURES
), they can use thecreateAccessIntent(java.lang.String)
. This is the recommend way, since it provides a simpler API and narrows the access to the given directory (and its descendants). - To get access to any directory (and its descendants), they can use the Storage Access Framework APIs (such as
Intent#ACTION_OPEN_DOCUMENT
andIntent#ACTION_OPEN_DOCUMENT_TREE
, although these APIs do not guarantee the user will select this specific volume. - To get read and write access to the primary storage volume, applications can declare the
android.Manifest.permission#READ_EXTERNAL_STORAGE
andandroid.Manifest.permission#WRITE_EXTERNAL_STORAGE
permissions respectively, with the latter including the former. This approach is discouraged, since users may be hesitant to grant broad access to all files contained on a storage device.
It can be obtained through StorageManager#getStorageVolumes()
and StorageManager#getPrimaryStorageVolume()
and also as an extra in some broadcasts (see EXTRA_STORAGE_VOLUME
).
See Environment#getExternalStorageDirectory()
for more info about shared/external storage semantics.
Summary
Constants | |
---|---|
static String |
Name of the |
Inherited constants | |
---|---|
Public methods | |
---|---|
Intent? |
createAccessIntent(directoryName: String!) Builds an intent to give access to a standard storage directory or entire volume after obtaining the user's approval. |
Intent |
Builds an |
Int | |
Boolean |
Indicates whether some other object is "equal to" this one. |
String! |
getDescription(context: Context!) Returns a user-visible description of the volume. |
File? |
Returns the directory where this volume is currently mounted. |
String? |
Return the volume name that can be used to interact with this storage device through |
UserHandle |
getOwner() Returns the user that owns this volume |
String! |
getState() Returns the current state of the volume. |
UUID? |
Gets the converted volume UUID. |
String? |
getUuid() Gets the volume UUID, if any. |
Int |
hashCode() |
Boolean |
Returns true if the volume is emulated. |
Boolean |
Returns true if the volume is the primary shared/external storage, which is the volume backed by |
Boolean |
Returns true if the volume is removable. |
String |
toString() |
Unit |
writeToParcel(parcel: Parcel, flags: Int) |
Properties | |
---|---|
static Parcelable.Creator<StorageVolume!> |
Constants
EXTRA_STORAGE_VOLUME
static val EXTRA_STORAGE_VOLUME: String
Name of the Parcelable
extra in the Intent#ACTION_MEDIA_REMOVED
, Intent#ACTION_MEDIA_UNMOUNTED
, Intent#ACTION_MEDIA_CHECKING
, Intent#ACTION_MEDIA_NOFS
, Intent#ACTION_MEDIA_MOUNTED
, Intent#ACTION_MEDIA_SHARED
, Intent#ACTION_MEDIA_BAD_REMOVAL
, Intent#ACTION_MEDIA_UNMOUNTABLE
, and Intent#ACTION_MEDIA_EJECT
broadcast that contains a StorageVolume
.
Value: "android.os.storage.extra.STORAGE_VOLUME"
Public methods
createAccessIntent
funcreateAccessIntent(directoryName: String!): Intent?
Deprecated: Callers should migrate to using Intent#ACTION_OPEN_DOCUMENT_TREE
instead. Launching this Intent
on devices running android.os.Build.VERSION_CODES#Q
or higher, will immediately finish with a result code of android.app.Activity#RESULT_CANCELED
.
Builds an intent to give access to a standard storage directory or entire volume after obtaining the user's approval.
When invoked, the system will ask the user to grant access to the requested directory (and its descendants). The result of the request will be returned to the activity through the onActivityResult
method.
To gain access to descendants (child, grandchild, etc) documents, use DocumentsContract#buildDocumentUriUsingTree(Uri, String)
, or DocumentsContract#buildChildDocumentsUriUsingTree(Uri, String)
with the returned URI.
If your application only needs to store internal data, consider using Context.getExternalFilesDirs
, Context#getExternalCacheDirs()
, or Context#getExternalMediaDirs()
, which require no permissions to read or write.
Access to the entire volume is only available for non-primary volumes (for the primary volume, apps can use the android.Manifest.permission#READ_EXTERNAL_STORAGE
and android.Manifest.permission#WRITE_EXTERNAL_STORAGE
permissions) and should be used with caution, since users are more likely to deny access when asked for entire volume access rather than specific directories.
Parameters | |
---|---|
directoryName |
String!: must be one of Environment#DIRECTORY_MUSIC , Environment#DIRECTORY_PODCASTS , Environment#DIRECTORY_RINGTONES , Environment#DIRECTORY_ALARMS , Environment#DIRECTORY_NOTIFICATIONS , Environment#DIRECTORY_PICTURES , Environment#DIRECTORY_MOVIES , Environment#DIRECTORY_DOWNLOADS , Environment#DIRECTORY_DCIM , or Environment#DIRECTORY_DOCUMENTS , or null to request access to the entire volume. |
Return | |
---|---|
Intent? |
intent to request access, or null if the requested directory is invalid for that volume. |
See Also
createOpenDocumentTreeIntent
fun createOpenDocumentTreeIntent(): Intent
Builds an Intent#ACTION_OPEN_DOCUMENT_TREE
to allow the user to grant access to any directory subtree (or entire volume) from the android.provider.DocumentsProvider
s available on the device. The initial location of the document navigation will be the root of this StorageVolume
. Note that the returned Intent
simply suggests that the user picks this StorageVolume
by default, but the user may select a different location. Callers must respect the user's chosen location, even if it is different from the originally requested location.
Return | |
---|---|
Intent |
intent to Intent#ACTION_OPEN_DOCUMENT_TREE initially showing the contents of this StorageVolume This value cannot be null . |
describeContents
fun describeContents(): Int
Return | |
---|---|
Int |
a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either 0 or android.os.Parcelable#CONTENTS_FILE_DESCRIPTOR |
equals
fun equals(other: Any?): Boolean
Indicates whether some other object is "equal to" this one.
The equals
method implements an equivalence relation on non-null object references:
- It is reflexive: for any non-null reference value
x
,x.equals(x)
should returntrue
. - It is symmetric: for any non-null reference values
x
andy
,x.equals(y)
should returntrue
if and only ify.equals(x)
returnstrue
. - It is transitive: for any non-null reference values
x
,y
, andz
, ifx.equals(y)
returnstrue
andy.equals(z)
returnstrue
, thenx.equals(z)
should returntrue
. - It is consistent: for any non-null reference values
x
andy
, multiple invocations ofx.equals(y)
consistently returntrue
or consistently returnfalse
, provided no information used inequals
comparisons on the objects is modified. - For any non-null reference value
x
,x.equals(null)
should returnfalse
.
An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.
Parameters | |
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obj |
This value may be null . |
Return | |
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Boolean |
true if this object is the same as the obj argument; false otherwise. |
getDescription
fun getDescription(context: Context!): String!
Returns a user-visible description of the volume.
Return | |
---|---|
String! |
the volume description |
getDirectory
fun getDirectory(): File?
Returns the directory where this volume is currently mounted.
Direct filesystem access via this path has significant emulation overhead, and apps are instead strongly encouraged to interact with media on storage volumes via the MediaStore
APIs.
This directory does not give apps any additional access beyond what they already have via MediaStore
.
Return | |
---|---|
File? |
directory where this volume is mounted, or null if the volume is not currently mounted. |
getMediaStoreVolumeName
fun getMediaStoreVolumeName(): String?
Return the volume name that can be used to interact with this storage device through MediaStore
.
Return | |
---|---|
String? |
opaque volume name, or null if this volume is not indexed by MediaStore . |
getOwner
fun getOwner(): UserHandle
Returns the user that owns this volume
Return | |
---|---|
UserHandle |
This value cannot be null . |
getState
fun getState(): String!
Returns the current state of the volume.
getStorageUuid
fun getStorageUuid(): UUID?
Gets the converted volume UUID. If a valid UUID is returned, it is compatible with other APIs that make use of UUID
like android.os.storage.StorageManager#allocateBytes and android.content.pm.ApplicationInfo#storageUuid
Return | |
---|---|
UUID? |
the UUID for the volume or null for "portable" storage devices which haven't been adopted. |
See Also
getUuid
fun getUuid(): String?
Gets the volume UUID, if any.
Return | |
---|---|
String? |
This value may be null . |
isEmulated
fun isEmulated(): Boolean
Returns true if the volume is emulated.
Return | |
---|---|
Boolean |
is emulated |
isPrimary
fun isPrimary(): Boolean
Returns true if the volume is the primary shared/external storage, which is the volume backed by Environment#getExternalStorageDirectory()
.
isRemovable
fun isRemovable(): Boolean
Returns true if the volume is removable.
Return | |
---|---|
Boolean |
is removable |
toString
fun toString(): String
Return | |
---|---|
String |
a string representation of the object. |
writeToParcel
fun writeToParcel(
parcel: Parcel,
flags: Int
): Unit
Parameters | |
---|---|
dest |
The Parcel in which the object should be written. This value cannot be null . |
flags |
Int: Additional flags about how the object should be written. May be 0 or PARCELABLE_WRITE_RETURN_VALUE . Value is either 0 or a combination of android.os.Parcelable#PARCELABLE_WRITE_RETURN_VALUE , and android.os.Parcelable.PARCELABLE_ELIDE_DUPLICATES |