我正致力于低功耗蓝牙 - BLE。
我可以扫描并查找，使用BLE通过蓝牙连接到固件设备。
mBluetoothGatt = mAl.get(pos).connectGatt(mContext, false, mGattCallback);
虽然来自Play商店的应用可以在固件设备中发现Services和Characteristics，但我的Android应用无法发现它们，它总是返回空服务列表。实际上，固件设备已经设置了Services和Characteristics。
我不知道为什么，谁知道原因，请帮助我如何发现Services和Characteristics，
谢谢，
Java代码
// Various callback methods defined by the BLE API.
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
if (newState == BluetoothProfile.STATE_CONNECTED) {
/**
* In case already connected to Pas device
*/
Log.i("", "Connected to GATT server. " + gatt.discoverServices());
// CALL THIS METHOD TO BEGIN DISCOVER SERVICES
gatt.discoverServices();
} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
/**
* In case disconnected Pas device
*/
Log.i("", "Disconnected from GATT server.");
}
}
@Override
// New services discovered
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
Log.i("", "onServicesDiscovered " + status + " " + gatt.discoverServices()
+ " " + gatt.getServices());
// RETURN : []
Log.i("", "gatt.getServices() " + gatt.getServices());
// RETURN : TRUE
Log.i("", "gatt.getServices() " + gatt.getServices().isEmpty());
// EXCEPTION HAPPEN BCS SIZE = 0
gatt.readCharacteristic(gatt.getServices().get(0).getCharacteristics().get(0));
if (status == BluetoothGatt.GATT_SUCCESS) {
} else {
Log.w("", "onServicesDiscovered received: " + status);
}
}
@Override
// Result of a characteristic read operation
public void onCharacteristicRead(
BluetoothGatt gatt, BluetoothGattCharacteristic characteristic,
int status) {
Log.i("", "onCharacteristicRead " + status + " " + characteristic);
if (status == BluetoothGatt.GATT_SUCCESS) {
}
}
};
// Device scan callback.
private BluetoothAdapter.LeScanCallback mLeScanCallback =
new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, int rssi,
byte[] scanRecord) {
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
/**
* Should show Scan Pas Devices :
* Add to array list scanned pas devices if it is not exist in list
* before
*/
if (!mAlPasDeviceNames.contains(device.getName())) {
mAlPasDevices.add(device);
mAlPasDeviceNames.add(device.getName());
// set adapter and show on UI
mLv.setAdapter(new PasConnectionAdapter(
getActivity(),
R.layout.simple_list_item_scan_pas_device,
mAlPasDevices));
}
}
});
}
};
logcat的
connect() - device: E2:5A:6B:5A:18:57, auto: false
D/BluetoothGatt: registerApp()
D/BluetoothGatt: registerApp() - UUID=93455863-c385-4563-9197-6592024cc8cc
D/BtGatt.GattService: registerClient() - UUID=93455863-c385-4563-9197-6592024cc8cc
D/BtGatt.GattService: onClientRegistered() - UUID=93455863-c385-4563-9197-6592024cc8cc, clientIf=5
D/BluetoothGatt: onClientRegistered() - status=0 clientIf=5
D/BtGatt.GattService: clientConnect() - address=E2:5A:6B:5A:18:57, isDirect=true
E/BluetoothRemoteDevices: aclStateChangeCallback: Device is NULL
D/BtGatt.GattService: onConnected() - clientIf=5, connId=5, address=E2:5A:6B:5A:18:57
D/BluetoothGatt: onClientConnectionState() - status=0 clientIf=5 device=E2:5A:6B:5A:18:57
D/BluetoothGatt: discoverServices() - device: E2:5A:6B:5A:18:57
D/BtGatt.GattService: discoverServices() - address=E2:5A:6B:5A:18:57, connId=5
I/: Connected to GATT server. true
D/BluetoothGatt: discoverServices() - device: E2:5A:6B:5A:18:57
D/BtGatt.GattService: discoverServices() - address=E2:5A:6B:5A:18:57, connId=5
D/BtGatt.GattService: onSearchCompleted() - connId=5, status=0
D/BtGatt.GattService: onSearchCompleted() - connId=5, status=0
E/BtGatt.btif: bta_to_btif_uuid: Unknown UUID length 61618!
E/BtGatt.btif: bta_to_btif_uuid: Unknown UUID length 61619!
I/: gatt.getService(uuid) null
D/BluetoothGatt: onSearchComplete() = Device=E2:5A:6B:5A:18:57 Status=0
D/BluetoothGatt: discoverServices() - device: E2:5A:6B:5A:18:57
D/BtGatt.GattService: discoverServices() - address=E2:5A:6B:5A:18:57, connId=5
D/BtGatt.GattService: onSearchCompleted() - connId=5, status=0
I/: onServicesDiscovered 0 true []
I/: gatt.getServices() []
I/: gatt.getServices() true
E/BtGatt.btif: bta_to_btif_uuid: Unknown UUID length 61621!
W/BluetoothGatt: Unhandled exception in callback
W/BluetoothGatt: java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
W/BluetoothGatt: at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
W/BluetoothGatt: at java.util.ArrayList.get(ArrayList.java:308)
W/BluetoothGatt: at ui.fragment.PasConnectionFragment$1.onServicesDiscovered(PasConnectionFragment.java:379)
W/BluetoothGatt: at android.bluetooth.BluetoothGatt$1.onSearchComplete(BluetoothGatt.java:304)
W/BluetoothGatt: at android.bluetooth.IBluetoothGattCallback$Stub.onTransact(IBluetoothGattCallback.java:217)
W/BluetoothGatt: at android.os.Binder.execTransact(Binder.java:446)
答案 0 :(得分：2)
检查以下代码，它将显示服务数量及其uuids
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
Log.e("BluetoothLeService", "onServicesDiscovered()");
if (status == BluetoothGatt.GATT_SUCCESS) {
List<BluetoothGattService> gattServices = mBluetoothGatt.getServices();
Log.e("onServicesDiscovered", "Services count: "+gattServices.size());
for (BluetoothGattService gattService : gattServices) {
String serviceUUID = gattService.getUuid().toString();
Log.e("onServicesDiscovered", "Service uuid "+serviceUUID);
}
} else {
Log.w(TAG, "onServicesDiscovered received: " + status);
}
}
答案 1 :(得分：1)
一个问题可能是您多次调用 gatt.discoverServices（）。 onConnectionStateChange方法中的两次：
Log.i("", "Connected to GATT server. " + gatt.discoverServices());
// CALL THIS METHOD TO BEGIN DISCOVER SERVICES
gatt.discoverServices();
然后再次在onServicesDiscovered方法中。
Log.i("", "onServicesDiscovered " + status + " " + gatt.discoverServices()
+ " " + gatt.getServices());
这意味着您反复启动服务扫描。不要在日志中调用它，一次就足够了。
答案 2 :(得分：0)
您可以按如下方式显示提供的服务和特征：
for (BluetoothGattService service : gatt.getServices()) {
Log.d(TAG, "Found Service " + service.getUuid().toString());
for(BluetoothGattCharacteristic mcharacteristic :service.getCharacteristics())
{
Log.d(TAG, "Found Characteristic " + mcharacteristic.getUuid().toString());
}
}
但也许这不会起作用，或者它只会显示通用属性配置文件o.e.然后，似乎制造商在使其余服务和特征可见之前交换了数据。在这种情况下，如果您使用Android手机，您可以使用hci日志并在wireshark中检查它。在那里你可以嗅到交换的包裹。它并不容易，并且取决于＆＃34; hack＆＃34;个人资料但没有文件，这是你唯一能做的事情。
答案 3 :(得分：0)
我遇到了同样的问题。我打电话给discoverServices()，但什么都没发生。然后我找到了解决方案。成功连接到设备后，您才必须呼叫discoverServices()。这是我的代码：
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
super.onConnectionStateChange(gatt, status, newState);
if(newState == BluetoothProfile.STATE_CONNECTED) {
Log.d(TAG, "Connected to GATT server, discovering services...");
gatt.discoverServices();
} else if(newState == BluetoothProfile.STATE_DISCONNECTED) {
Log.d(TAG, "Disconnected from GATT server");
}
}
在这里，我尝试仅在连接到设备后发现服务。这对我有用，我可以在onServicesDiscovered()方法中检索所需的服务ID。
希望我能帮忙...