UsbManager
public
class
UsbManager
extends Object
java.lang.Object | |
↳ | android.hardware.usb.UsbManager |
This class allows you to access the state of USB and communicate with USB devices. Currently only host mode is supported in the public API.
Developer Guides
For more information about communicating with USB hardware, read the USB developer guide.
Summary
Constants | |
---|---|
String |
ACTION_USB_ACCESSORY_ATTACHED
Activity intent sent when user attaches a USB accessory. |
String |
ACTION_USB_ACCESSORY_DETACHED
Broadcast Action: A broadcast for USB accessory detached event. |
String |
ACTION_USB_DEVICE_ATTACHED
Activity intent sent when user attaches a USB device. |
String |
ACTION_USB_DEVICE_DETACHED
Broadcast Action: A broadcast for USB device detached event. |
String |
EXTRA_ACCESSORY
Name of extra for |
String |
EXTRA_DEVICE
Name of extra for |
String |
EXTRA_PERMISSION_GRANTED
Name of extra added to the |
Public methods | |
---|---|
UsbAccessory[]
|
getAccessoryList()
Returns a list of currently attached USB accessories. |
HashMap<String, UsbDevice>
|
getDeviceList()
Returns a HashMap containing all USB devices currently attached. |
boolean
|
hasPermission(UsbAccessory accessory)
Returns true if the caller has permission to access the accessory. |
boolean
|
hasPermission(UsbDevice device)
Returns true if the caller has permission to access the device. |
ParcelFileDescriptor
|
openAccessory(UsbAccessory accessory)
Opens a file descriptor for reading and writing data to the USB accessory. |
UsbDeviceConnection
|
openDevice(UsbDevice device)
Opens the device so it can be used to send and receive
data using |
void
|
requestPermission(UsbDevice device, PendingIntent pi)
Requests temporary permission for the given package to access the device. |
void
|
requestPermission(UsbAccessory accessory, PendingIntent pi)
Requests temporary permission for the given package to access the accessory. |
Inherited methods | |
---|---|
Constants
ACTION_USB_ACCESSORY_ATTACHED
public static final String ACTION_USB_ACCESSORY_ATTACHED
Activity intent sent when user attaches a USB accessory.
-
EXTRA_ACCESSORY
containing theUsbAccessory
for the attached accessory
Constant Value: "android.hardware.usb.action.USB_ACCESSORY_ATTACHED"
ACTION_USB_ACCESSORY_DETACHED
public static final String ACTION_USB_ACCESSORY_DETACHED
Broadcast Action: A broadcast for USB accessory detached event. This intent is sent when a USB accessory is detached.
-
EXTRA_ACCESSORY
containing theUsbAccessory
for the attached accessory that was detached
Constant Value: "android.hardware.usb.action.USB_ACCESSORY_DETACHED"
ACTION_USB_DEVICE_ATTACHED
public static final String ACTION_USB_DEVICE_ATTACHED
Activity intent sent when user attaches a USB device. This intent is sent when a USB device is attached to the USB bus when in host mode.
-
EXTRA_DEVICE
containing theUsbDevice
for the attached device
Constant Value: "android.hardware.usb.action.USB_DEVICE_ATTACHED"
ACTION_USB_DEVICE_DETACHED
public static final String ACTION_USB_DEVICE_DETACHED
Broadcast Action: A broadcast for USB device detached event. This intent is sent when a USB device is detached from the USB bus when in host mode.
-
EXTRA_DEVICE
containing theUsbDevice
for the detached device
Constant Value: "android.hardware.usb.action.USB_DEVICE_DETACHED"
EXTRA_ACCESSORY
public static final String EXTRA_ACCESSORY
Name of extra for ACTION_USB_ACCESSORY_ATTACHED
and
ACTION_USB_ACCESSORY_DETACHED
broadcasts
containing the UsbAccessory
object for the accessory.
Constant Value: "accessory"
EXTRA_DEVICE
public static final String EXTRA_DEVICE
Name of extra for ACTION_USB_DEVICE_ATTACHED
and
ACTION_USB_DEVICE_DETACHED
broadcasts
containing the UsbDevice
object for the device.
Constant Value: "device"
EXTRA_PERMISSION_GRANTED
public static final String EXTRA_PERMISSION_GRANTED
Name of extra added to the PendingIntent
passed into requestPermission(android.hardware.usb.UsbDevice, android.app.PendingIntent)
or requestPermission(android.hardware.usb.UsbAccessory, android.app.PendingIntent)
containing a boolean value indicating whether the user granted permission or not.
Constant Value: "permission"
Public methods
getAccessoryList
public UsbAccessory[] getAccessoryList ()
Returns a list of currently attached USB accessories.
(in the current implementation there can be at most one)
Requires the PackageManager#FEATURE_USB_ACCESSORY
feature which can be detected using PackageManager.hasSystemFeature(String)
.
Returns | |
---|---|
UsbAccessory[] |
list of USB accessories, or null if none are attached. |
getDeviceList
public HashMap<String, UsbDevice> getDeviceList ()
Returns a HashMap containing all USB devices currently attached.
USB device name is the key for the returned HashMap.
The result will be empty if no devices are attached, or if
USB host mode is inactive or unsupported.
Requires the PackageManager#FEATURE_USB_HOST
feature which can be detected using PackageManager.hasSystemFeature(String)
.
Returns | |
---|---|
HashMap<String, UsbDevice> |
HashMap containing all connected USB devices. |
hasPermission
public boolean hasPermission (UsbAccessory accessory)
Returns true if the caller has permission to access the accessory.
Permission might have been granted temporarily via
requestPermission(android.hardware.usb.UsbAccessory, android.app.PendingIntent)
or
by the user choosing the caller as the default application for the accessory.
Requires the PackageManager#FEATURE_USB_ACCESSORY
feature which can be detected using PackageManager.hasSystemFeature(String)
.
Parameters | |
---|---|
accessory |
UsbAccessory : to check permissions for |
Returns | |
---|---|
boolean |
true if caller has permission |
hasPermission
public boolean hasPermission (UsbDevice device)
Returns true if the caller has permission to access the device.
Permission might have been granted temporarily via
requestPermission(android.hardware.usb.UsbDevice, android.app.PendingIntent)
or
by the user choosing the caller as the default application for the device.
Permission for USB devices of class UsbConstants.USB_CLASS_VIDEO
for clients that
target SDK Build.VERSION_CODES.P
and above can be granted only if they
have additionally the Manifest.permission.CAMERA
permission.
Requires the PackageManager#FEATURE_USB_HOST
feature which can be detected using PackageManager.hasSystemFeature(String)
.
Parameters | |
---|---|
device |
UsbDevice : to check permissions for |
Returns | |
---|---|
boolean |
true if caller has permission |
openAccessory
public ParcelFileDescriptor openAccessory (UsbAccessory accessory)
Opens a file descriptor for reading and writing data to the USB accessory.
If data is read from the InputStream
created from this file descriptor all
data of a USB transfer should be read at once. If only a partial request is read the rest of
the transfer is dropped.
It is strongly recommended to use newer methods instead of this method,
since this method may provide sub-optimal performance on some devices.
This method could potentially face interim performance degradation as well.
Requires the PackageManager#FEATURE_USB_ACCESSORY
feature which can be detected using PackageManager.hasSystemFeature(String)
.
Parameters | |
---|---|
accessory |
UsbAccessory : the USB accessory to open |
Returns | |
---|---|
ParcelFileDescriptor |
file descriptor, or null if the accessory could not be opened. |
openDevice
public UsbDeviceConnection openDevice (UsbDevice device)
Opens the device so it can be used to send and receive
data using UsbRequest
.
Requires the PackageManager#FEATURE_USB_HOST
feature which can be detected using PackageManager.hasSystemFeature(String)
.
Parameters | |
---|---|
device |
UsbDevice : the device to open |
Returns | |
---|---|
UsbDeviceConnection |
a UsbDeviceConnection , or null if open failed |
requestPermission
public void requestPermission (UsbDevice device, PendingIntent pi)
Requests temporary permission for the given package to access the device.
This may result in a system dialog being displayed to the user
if permission had not already been granted.
Success or failure is returned via the PendingIntent
pi.
If successful, this grants the caller permission to access the device only
until the device is disconnected.
The following extras will be added to pi:
-
EXTRA_DEVICE
containing the device passed into this call -
EXTRA_PERMISSION_GRANTED
containing boolean indicating whether permission was granted by the user
UsbConstants.USB_CLASS_VIDEO
for clients that
target SDK Build.VERSION_CODES.P
and above can be granted only if they
have additionally the Manifest.permission.CAMERA
permission.
Requires the
PackageManager#FEATURE_USB_HOST
feature which can be detected using PackageManager.hasSystemFeature(String)
.
Parameters | |
---|---|
device |
UsbDevice : to request permissions for |
pi |
PendingIntent : PendingIntent for returning result |
requestPermission
public void requestPermission (UsbAccessory accessory, PendingIntent pi)
Requests temporary permission for the given package to access the accessory.
This may result in a system dialog being displayed to the user
if permission had not already been granted.
Success or failure is returned via the PendingIntent
pi.
If successful, this grants the caller permission to access the accessory only
until the device is disconnected.
The following extras will be added to pi:
-
EXTRA_ACCESSORY
containing the accessory passed into this call -
EXTRA_PERMISSION_GRANTED
containing boolean indicating whether permission was granted by the user
Requires the
PackageManager#FEATURE_USB_ACCESSORY
feature which can be detected using PackageManager.hasSystemFeature(String)
.
Parameters | |
---|---|
accessory |
UsbAccessory : to request permissions for |
pi |
PendingIntent : PendingIntent for returning result |