我正在尝试将BLE设备与Android应用程序连接。我在前台获取设备名称，Mac地址和rssi值。我不知道如何在后台扫描设备并获取特定设备的详细信息，如MAC地址，rssi值。
答案 0 :(得分：2)
您必须在后台为该启动粘性服务执行所有操作，并在该服务的onStartCommand中开始扫描。
RewriteBase /demo/
在manifest.xml中
package com.myapp.services;
import java.util.List;
import android.annotation.TargetApi;
import android.app.Service;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothManager;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.preference.PreferenceManager;
import android.support.v4.content.LocalBroadcastManager;
import android.text.TextUtils;
import android.widget.Toast;
import com.myapp.R;
/**Both RX and RSSI (Received Signal Strength Indication) are indications of the power level being received
* by an antenna
* The difference between RX and RSSI is that RX is measured in milliWatts (mW) or decibel-milliwatts (dBm)
* whereas RSSI is a signal strength percentage—the higher the RSSI number, the stronger the signal
*
*/
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
public class BeaconService extends Service implements BluetoothAdapter.LeScanCallback{
private static final String TAG = BeaconService.class.getSimpleName();
private BluetoothGatt btGatt;
private BluetoothAdapter mBluetoothAdapter;
@Override
public void onCreate() {
super.onCreate();
writeLine("Automate service created...");
getBTService();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
writeLine("Automate service start...");
if (!isBluetoothSupported()) {
Toast.makeText(this, R.string.ble_not_supported, Toast.LENGTH_SHORT).show();
stopSelf();
}else{
if(mBluetoothAdapter!=null && mBluetoothAdapter.isEnabled()){
startBLEscan();
}else{
stopSelf();
}
}
return START_STICKY;
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onDestroy() {
writeLine("Automate service destroyed...");
stopBLEscan();
super.onDestroy();
if(btGatt!=null){
btGatt.disconnect();
btGatt.close();
btGatt = null;
}
}
@Override
public boolean stopService(Intent name) {
writeLine("Automate service stop...");
stopSelf();
return super.stopService(name);
}
// Initializes a Bluetooth adapter. For API level 18 and above, get a reference to
// BluetoothAdapter through BluetoothManager.
public BluetoothAdapter getBTService(){
BluetoothManager btManager = (BluetoothManager) getApplicationContext().getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter = (BluetoothAdapter) btManager.getAdapter();
return mBluetoothAdapter;
}
public boolean isBluetoothSupported() {
return this.getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE);
}
public void startBLEscan(){
mBluetoothAdapter.startLeScan(this);
}
public void stopBLEscan(){
mBluetoothAdapter.stopLeScan(this);
}
/**
*
* @param enable
*/
public void scanLeDevice(final boolean enable) {
if (enable) {
startBLEscan();
} else {
stopBLEscan();
}
}
public static void enableDisableBluetooth(boolean enable){
BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (bluetoothAdapter != null) {
if(enable) {
bluetoothAdapter.enable();
}else{
bluetoothAdapter.disable();
}
}
}
@Override
public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) {
if(device!=null && device.getName()!=null){
//Log.d(TAG + " onLeScan: ", "Name: "+device.getName() + "Address: "+device.getAddress()+ "RSSI: "+rssi);
if(rssi > -90 && rssi <-1){
writeLine("Automate service BLE device in range: "+ device.getName()+ " "+rssi);
if (device.getName().equalsIgnoreCase("NCS_Beacon") || device.getName().equalsIgnoreCase("estimote")) {
//This Main looper thread is main for connect gatt, don't remove it
// Although you need to pass an appropriate context getApplicationContext(),
//Here if you use Looper.getMainLooper() it will stop getting callback and give internal exception fail to register //callback
new Handler(getApplicationContext().getMainLooper()).post(new Runnable() {
@Override
public void run() {
btGatt = device.connectGatt(getApplicationContext(), false, bleGattCallback);
Log.e(TAG, "onLeScan btGatt value returning from connectGatt "+btGatt);
}
});
}
stopBLEscan();
}else{
//Log.v("Device Scan Activity", device.getAddress()+" "+"BT device is still too far - not connecting");
}
}
}
BluetoothGattCallback bleGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(final BluetoothGatt gatt, int status, int newState) {
super.onConnectionStateChange(gatt, status, newState);
writeLine("Automate service connection state: "+ newState);
if (newState == android.bluetooth.BluetoothProfile.STATE_CONNECTED){
writeLine("Automate service connection state: STATE_CONNECTED");
Log.v("BLEService", "BLE Connected now discover services");
Log.v("BLEService", "BLE Connected");
new Thread(new Runnable() {
@Override
public void run() {
writeLine("Automate service go for discover services");
gatt.discoverServices();
}
}).start();
}else if (newState == android.bluetooth.BluetoothProfile.STATE_DISCONNECTED){
writeLine("Automate service connection state: STATE_DISCONNECTED");
Log.v("BLEService", "BLE Disconnected");
}
}
@Override
public void onServicesDiscovered(final BluetoothGatt gatt, int status) {
super.onServicesDiscovered(gatt, status);
if (status == BluetoothGatt.GATT_SUCCESS) {
writeLine("Automate service discover service: GATT_SUCCESS");
Log.v("BLEService", "BLE Services onServicesDiscovered");
//Get service
List<BluetoothGattService> services = gatt.getServices();
writeLine("Automate service discover service imei: " +imei);
}
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
super.onCharacteristicRead(gatt, characteristic, status);
}
@Override
public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
super.onCharacteristicChanged(gatt, characteristic);
}
};
private void writeLine(final String message) {
Handler h = new Handler(getApplicationContext().getMainLooper());
// Although you need to pass an appropriate context
h.post(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),message,Toast.LENGTH_SHORT).show();
}
});
}
}
答案 1 :(得分：0)
当应用程序在android中处于后台时，使用服务扫描并连接ble设备。
<service android:name=".service.BackgroundService" />
将此代码写入manifest.xml
$ less notexists.txt
notexists.txt: No such file or directory
$ echo $?
1