現在、BLE デバイスに書き込みを行ってビープ音を鳴らすメソッドがあります。私のBluetoothコールバックは次のようになります：
public class ReadWriteCharacteristic extends BluetoothGattCallback {
public ReadWriteCharacteristic(Context context, String macAddress, UUID service, UUID characteristic, Object tag, Activity activity) {
mMacAddress = macAddress;
mService = service;
mCharacteristic = characteristic;
mTag = tag;
mContext = context;
this.activity =activity;
final BluetoothManager bluetoothManager =
(BluetoothManager) mContext.getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter = bluetoothManager.getAdapter();
}
final private static String TAG = "ReadCharacteristic";
private Object mTag;
private String mMacAddress;
private UUID mService;
private BluetoothManager mBluetoothManager = null;
private BluetoothAdapter mBtAdapter = null;
private BluetoothGatt mBluetoothGatt = null;
private String mBluetoothDeviceAddress ="";
private UUID mCharacteristic;
BluetoothDevice device;
private Activity activity;
private BluetoothAdapter mBluetoothAdapter;
private Context mContext;
ReadWriteCharacteristic rc;
private int retry = 5;
public String getMacAddress() {
return mMacAddress;
}
public UUID getService() {
return mService;
}
public UUID getCharacteristic() {
return mCharacteristic;
}
public byte[] getValue() { return mValue; }
public void onError() {
Log.w(TAG, "onError");
}
public void readCharacteristic(){
if (retry == 0)
{
onError();
return;
}
retry--;
device = mBluetoothAdapter.getRemoteDevice(getMacAddress());
mBluetoothManager = (BluetoothManager) mContext.getSystemService(Context.BLUETOOTH_SERVICE);
int connectionState = mBluetoothManager.getConnectionState(device,
BluetoothProfile.GATT);
if (device != null) {
if (connectionState == BluetoothProfile.STATE_DISCONNECTED)
{
// Previously connected device. Try to reconnect.
if (mBluetoothDeviceAddress != null
&& getMacAddress().equals(mBluetoothDeviceAddress)
&& mBluetoothGatt != null) {
Log.w(TAG, "Re-use GATT connection");
if (mBluetoothGatt.connect()) {
Log.w(TAG, "Already connected, discovering services");
mBluetoothGatt.discoverServices();
//return ;
} else {
Log.w(TAG, "GATT re-connect failed.");
return;
}
}
if (device == null) {
Log.w(TAG, "Device not found. Unable to connect.");
return;
}
Log.w(TAG, "Create a new GATT connection.");
rc= ReadWriteCharacteristic.this;
Log.w(TAG, "Starting Read [" + getService() + "|" + getCharacteristic() + "]");
mBluetoothGatt = device.connectGatt(mContext, false, rc);
refreshDeviceCache(mBluetoothGatt);
mBluetoothDeviceAddress = getMacAddress();
} else {
Log.w(TAG, "Attempt to connect in state: " + connectionState);
if(mBluetoothGatt!=null)
mBluetoothGatt.close();
readCharacteristic();
}
}
}
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
super.onConnectionStateChange(gatt, status, newState);
Log.w(TAG,"onConnectionStateChange [" + status + "|" + newState + "]");
if ((newState == 2)&&(status ==0)) {
gatt.discoverServices();
}
else if(status == 133 )
{
//gatt.disconnect();
gatt.close();
mBluetoothGatt = null;
try
{
Thread.sleep(2000);
}
catch(Exception e)
{
}
readCharacteristic();
}
else{
if(mBluetoothGatt!=null)
mBluetoothGatt.close();
// gatt.close();
Log.w(TAG, "[" + status + "]");
//gatt.disconnect();
try
{
Thread.sleep(2000);
}
catch(Exception e)
{
}
mBluetoothGatt = null;
readCharacteristic();
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
Log.w(TAG,"onServicesDiscovered [" + status + "]");
BluetoothGattService bgs = gatt.getService(getService());
if (bgs != null) {
BluetoothGattCharacteristic bgc = bgs.getCharacteristic(getCharacteristic());
gatt.readCharacteristic(bgc);
}
}
@Override
public void onCharacteristicWrite(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic,
int status) {
Log.w(TAG,"onCharacteristicWrite [" + status + "]");
if (status == BluetoothGatt.GATT_SUCCESS) {
Log.w(TAG,"onCharacteristicWrite [" + getDataHex(characteristic.getValue()) + "]");
// gatt.disconnect();
if(mBluetoothGatt!=null)
mBluetoothGatt.close();
// gatt.close();
// mBluetoothGatt=null;
}
else if(status ==133)
{
gatt.close();
try
{
Thread.sleep(2000);
}
catch(Exception e)
{
}
readCharacteristic();
}
else{
//gatt.disconnect();
gatt.close();
}
}
@Override
public void onCharacteristicRead(BluetoothGatt gatt,
BluetoothGattCharacteristic characteristic,
int status) {
Log.w(TAG,"onCharacteristicRead [" + status + "]");
if (status == BluetoothGatt.GATT_SUCCESS) {
mValue = characteristic.getValue();
// Perform write operations
gatt.writeCharacteristic(bgc);
}
else if(status ==133)
{
gatt.close();
try
{
Thread.sleep(2000);
}
catch(Exception e)
{
}
readCharacteristic();
}
else {
// gatt.disconnect();
gatt.close();
}
}
}
このコードは、Kitkat 以前を実行しているデバイスで完全に機能します。ただし、Lollipop を実行しているデバイスでは、このコードは最初のインスタンスで問題なく動作します。しかし、次のインスタンスから、接続を切断するか閉じて再試行するかに関係なく、機能しません。onConnectionStateChange メソッドでステータス コード 257 が表示され続けます。私の知る限り、Bluetooth GATT メソッドは、kitkat デバイスと Lollipop デバイスの両方で同じです。
驚いたことに、古い BLE API、つまり startLeScan (たとえば - mBluetoothAdapter.startLeScan(mLeScanCallback);) を使用すると、このコードは Lollipop デバイスで正常に動作します。この問題は、新しい BLE API、つまり BluetoothLeScanner ( ) を使用した場合にのみ発生します scanner.startScan(filters, settings, new scancallback());。古い BLE API を使用している Lollipop デバイスではスキャン速度が非常に遅く、使用できません。この問題の解決方法がわかりません。同じ問題に直面して解決策を見つけた人はいますか? どんな助けでも大歓迎です。