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我想發送消息給BLE設備。根據我的理解,首先必須發現設備服務,然後將消息發送到服務特性。因此,這裏是我做過什麼:從未發現的BLE服務
public class BluetoothLeService extends Service {
private BluetoothManager mBluetoothManager;
private BluetoothAdapter mBluetoothAdapter;
private String mBluetoothDeviceAddress;
private BluetoothGatt mBluetoothGatt;
private String macAddress;
private String serviceUuid;
private String characteristicUuid;
private Application app;
private int transmissionValue = 450;
public BluetoothLeService(String address, String serviceUuid, String characteristicUuid) {
this.macAddress = address;
this.serviceUuid = serviceUuid;
this.characteristicUuid = characteristicUuid;
}
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
System.out.println("connectionStateChange: " + status);
if (STATE_CONNECTED == newState) {
gatt.discoverServices();
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
if(gatt.getDevice().getName().equals("MyDeviceName")) {
sendMessageAfterDiscovery(gatt);
}
}
};
public boolean initialize(Application app) {
this.app = app;
if (mBluetoothManager == null) {
mBluetoothManager = (BluetoothManager) app.getSystemService(Context.BLUETOOTH_SERVICE);
if (mBluetoothManager == null) {
return false;
}
}
mBluetoothAdapter = mBluetoothManager.getAdapter();
if (mBluetoothAdapter == null) {
return false;
}
return true;
}
public boolean connect() {
return connect(macAddress);
}
public boolean connect(final String address) {
this.macAddress = address;
if (mBluetoothAdapter == null || macAddress == null) {
return false;
}
final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(macAddress);
if (device == null) {
Log.w(TAG, "Device not found. Unable to connect.");
return false;
}
mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
return true;
}
public void writeCharacteristic(int value) {
this.transmissionValue = value;
BluetoothDevice mDevice = mBluetoothAdapter.getRemoteDevice(this.macAddress);
BluetoothGatt mBG = mDevice.connectGatt(app.getApplicationContext(), true, mGattCallback);
System.out.println("device name: " + mBG.getDevice().getName());
}
private void sendMessageAfterDiscovery(BluetoothGatt gatt) {
BluetoothGattService mSVC = gatt.getService(UUID.fromString(serviceUuid));
BluetoothGattCharacteristic mCH = mSVC.getCharacteristic(UUID.fromString(characteristicUuid));
mCH.setValue(transmissionValue, BluetoothGattCharacteristic.FORMAT_UINT16, 0);
System.out.println("characteristic writable: " + isCharacteristicWriteable(mCH));
System.out.println("success? " + gatt.writeCharacteristic(mCH));
}
public static boolean isCharacteristicWriteable(BluetoothGattCharacteristic pChar) {
return (pChar.getProperties() & (BluetoothGattCharacteristic.PROPERTY_WRITE | BluetoothGattCharacteristic.PROPERTY_WRITE_NO_RESPONSE)) != 0;
}
}
而這裏就是我要發送消息的代碼:
private void sendMessage() {
BluetoothLeService ble = new BluetoothLeService("B0:00:00:00:00:C0", "0000fff0-1111-0000-0000-00805f9b34fb","0000fff1-1111-0000-0000-00805f9b34fb");
ble.initialize(app);
ble.connect();,
ble.writeCharacteristic(450)
}
現在,每當我想連接到該設備併發送一條消息,onServiceDiscovered方法從未被調用,雖然設備被識別,因爲我可以獲取設備的名稱。也沒有錯誤被拋出。
爲什麼此方法從未被調用過?難道我做錯了什麼? 我已經檢查了權限,並在清單中將該類添加爲服務。
感謝您的幫助......
我只是去嘗試; 但是當我在onConnectionStateChange中調用它時,這個方法永遠不會被調用,但我仍然在connectGatt之後得到deviceName; 我更新了代碼 –
您是否已驗證連接狀態是否以'STATE_CONNECTED'返回? – stkent
onConnectionStateChange永遠不會被調用;所以沒有連接狀態來檢查。 –