Added in API level 21

BluetoothLeScanner

---

Kotlin |Java

class BluetoothLeScanner

kotlin.Any
↳	android.bluetooth.le.BluetoothLeScanner

This class provides methods to perform scan related operations for Bluetooth LE devices. An application can scan for a particular type of Bluetooth LE devices using ScanFilter. It can also request different types of callbacks for delivering the result.

Use BluetoothAdapter#getBluetoothLeScanner() to get an instance of BluetoothLeScanner.

Summary

Constants
static String	EXTRA_CALLBACK_TYPE Optional extra indicating the callback type, which will be one of CALLBACK_TYPE_* constants in ScanSettings.
static String	EXTRA_ERROR_CODE Optional extra indicating the error code, if any.
static String	EXTRA_LIST_SCAN_RESULT Extra containing a list of ScanResults.

Public methods
Unit	flushPendingScanResults(callback: ScanCallback!) Flush pending batch scan results stored in Bluetooth controller.
Unit	startScan(callback: ScanCallback!) Start Bluetooth LE scan with default parameters and no filters.
Unit	startScan(filters: MutableList<ScanFilter!>!, settings: ScanSettings!, callback: ScanCallback!) Start Bluetooth LE scan.
Int	startScan(filters: MutableList<ScanFilter!>?, settings: ScanSettings?, callbackIntent: PendingIntent) Start Bluetooth LE scan using a PendingIntent.
Unit	stopScan(callback: ScanCallback!) Stops an ongoing Bluetooth LE scan.
Unit	stopScan(callbackIntent: PendingIntent!) Stops an ongoing Bluetooth LE scan started using a PendingIntent.

Constants

EXTRA_CALLBACK_TYPE

Added in API level 26

static val EXTRA_CALLBACK_TYPE: String

Optional extra indicating the callback type, which will be one of CALLBACK_TYPE_* constants in ScanSettings.

Value: "android.bluetooth.le.extra.CALLBACK_TYPE"

See Also

• android.bluetooth.le.ScanCallback#onScanResult(int, ScanResult)

EXTRA_ERROR_CODE

Added in API level 26

static val EXTRA_ERROR_CODE: String

Optional extra indicating the error code, if any. The error code will be one of the SCAN_FAILED_* codes in ScanCallback.

Value: "android.bluetooth.le.extra.ERROR_CODE"

EXTRA_LIST_SCAN_RESULT

Added in API level 26

static val EXTRA_LIST_SCAN_RESULT: String

Extra containing a list of ScanResults. It can have one or more results if there was no error. In case of error, EXTRA_ERROR_CODE will contain the error code and this extra will not be available.

Value: "android.bluetooth.le.extra.LIST_SCAN_RESULT"

Public methods

flushPendingScanResults

Added in API level 21

fun flushPendingScanResults(callback: ScanCallback!): Unit

Flush pending batch scan results stored in Bluetooth controller. This will return Bluetooth LE scan results batched on bluetooth controller. Returns immediately, batch scan results data will be delivered through the callback.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH_ADMIN permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_SCAN permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_SCAN

Parameters
callback	ScanCallback!: Callback of the Bluetooth LE Scan, it has to be the same instance as the one used to start scan.

startScan

Added in API level 21

fun startScan(callback: ScanCallback!): Unit

Start Bluetooth LE scan with default parameters and no filters. The scan results will be delivered through callback. For unfiltered scans, scanning is stopped on screen off to save power. Scanning is resumed when screen is turned on again. To avoid this, use startScan(java.util.List,android.bluetooth.le.ScanSettings,android.bluetooth.le.ScanCallback) with desired ScanFilter.

An app must have ACCESS_COARSE_LOCATION permission in order to get results. An App targeting Android Q or later must have ACCESS_FINE_LOCATION permission in order to get results.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH_ADMIN permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_SCAN permission which can be gained with android.app.Activity#requestPermissions(String[], int).
In addition, this requires either the Manifest.permission#ACCESS_FINE_LOCATION permission or a strong assertion that you will never derive the physical location of the device. You can make this assertion by declaring usesPermissionFlags="neverForLocation" on the relevant <uses-permission> manifest tag, but it may restrict the types of Bluetooth devices you can interact with.
Requires android.Manifest.permission#BLUETOOTH_SCAN

Parameters
callback	ScanCallback!: Callback used to deliver scan results.

Exceptions
java.lang.IllegalArgumentException	If callback is null.

startScan

Added in API level 21

fun startScan(
    filters: MutableList<ScanFilter!>!, 
    settings: ScanSettings!, 
    callback: ScanCallback!
): Unit

Start Bluetooth LE scan. The scan results will be delivered through callback. For unfiltered scans, scanning is stopped on screen off to save power. Scanning is resumed when screen is turned on again. To avoid this, do filtered scanning by using proper ScanFilter.

An app must have ACCESS_COARSE_LOCATION permission in order to get results. An App targeting Android Q or later must have ACCESS_FINE_LOCATION permission in order to get results.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH_ADMIN permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_SCAN permission which can be gained with android.app.Activity#requestPermissions(String[], int).
In addition, this requires either the Manifest.permission#ACCESS_FINE_LOCATION permission or a strong assertion that you will never derive the physical location of the device. You can make this assertion by declaring usesPermissionFlags="neverForLocation" on the relevant <uses-permission> manifest tag, but it may restrict the types of Bluetooth devices you can interact with.
Requires android.Manifest.permission#BLUETOOTH_SCAN

Parameters
filters	MutableList<ScanFilter!>!: ScanFilters for finding exact BLE devices.
settings	ScanSettings!: Settings for the scan.
callback	ScanCallback!: Callback used to deliver scan results.

Exceptions
java.lang.IllegalArgumentException	If settings or callback is null.

startScan

Added in API level 26

fun startScan(
    filters: MutableList<ScanFilter!>?, 
    settings: ScanSettings?, 
    callbackIntent: PendingIntent
): Int

Start Bluetooth LE scan using a PendingIntent. The scan results will be delivered via the PendingIntent. Use this method of scanning if your process is not always running and it should be started when scan results are available.

An app must have ACCESS_COARSE_LOCATION permission in order to get results. An App targeting Android Q or later must have ACCESS_FINE_LOCATION permission in order to get results.

When the PendingIntent is delivered, the Intent passed to the receiver or activity will contain one or more of the extras EXTRA_CALLBACK_TYPE, EXTRA_ERROR_CODE and EXTRA_LIST_SCAN_RESULT to indicate the result of the scan.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH_ADMIN permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_SCAN permission which can be gained with android.app.Activity#requestPermissions(String[], int).
In addition, this requires either the Manifest.permission#ACCESS_FINE_LOCATION permission or a strong assertion that you will never derive the physical location of the device. You can make this assertion by declaring usesPermissionFlags="neverForLocation" on the relevant <uses-permission> manifest tag, but it may restrict the types of Bluetooth devices you can interact with.
Requires android.Manifest.permission#BLUETOOTH_SCAN

Parameters
filters	MutableList<ScanFilter!>?: Optional list of ScanFilters for finding exact BLE devices. This value may be null.
settings	ScanSettings?: Optional settings for the scan. This value may be null.
callbackIntent	PendingIntent: The PendingIntent to deliver the result to. This value cannot be null.

Return
Int	Returns 0 for success or an error code from ScanCallback if the scan request could not be sent.

See Also

• #stopScan(PendingIntent)

stopScan

Added in API level 21

fun stopScan(callback: ScanCallback!): Unit

Stops an ongoing Bluetooth LE scan.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH_ADMIN permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_SCAN permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_SCAN

stopScan

Added in API level 26

fun stopScan(callbackIntent: PendingIntent!): Unit

Stops an ongoing Bluetooth LE scan started using a PendingIntent. When creating the PendingIntent parameter, please do not use the FLAG_CANCEL_CURRENT flag. Otherwise, the stop scan may have no effect.
For apps targeting Build.VERSION_CODES#R or lower, this requires the Manifest.permission#BLUETOOTH_ADMIN permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES#S or or higher, this requires the Manifest.permission#BLUETOOTH_SCAN permission which can be gained with android.app.Activity#requestPermissions(String[], int).
Requires android.Manifest.permission#BLUETOOTH_SCAN

Parameters
callbackIntent	PendingIntent!: The PendingIntent that was used to start the scan.

See Also

• #startScan(List, ScanSettings, PendingIntent)