Android 9.0 蓝牙电话BluetoothHeadsetClient

BluetoothHeadsetClient
主要实现HFP协议，主要实现拨打、接听、挂断电话（AG侧、HF侧）、切换声道功能。

AG（Audio Gate）音频网关—音频设备输入输出网关 。
HF（Hands Free）免提—该设备作为音频网关的远程音频输入/输出机制，并可提供若干遥控功能。
在车载蓝牙中，手机侧是AG，车载蓝牙侧是HF，在android源代码中，将AG侧称为HFP/AG，将HF侧称为HFPClient/HF。
BluetoothHeadsetClient初始化

/**
 * 连接服务
 */
private void getProfileProxy() {
   mAdapter.getProfileProxy(mContext, new ProxyServiceListener(), BluetoothProfile.HEADSET_CLIENT);
}
private final class ProxyServiceListener implements BluetoothProfile.ServiceListener {

   @Override
   public void onServiceConnected(int profile, BluetoothProfile proxy) {
      Log.d(TAG,"Bluetooth service connected profile == "+profile);
      if (profile == BluetoothProfile.HEADSET_CLIENT) {
         isHeadSetProfileReady = true;
         mHeadsetClient = (BluetoothHeadsetClient)proxy;
      } 
   }

   @Override
   public void onServiceDisconnected(int profile) {
      if (profile == BluetoothProfile.HEADSET_CLIENT) {
         isHeadSetProfileReady = false;
         mHeadsetClient = null;
      }
   }
}
BluetoothHeadsetClient连接设备
//获取连接状态
public int getConnectionState() {
   if (mHeadsetClient != null) {
      List<BluetoothDevice> deviceList = mHeadsetClient.getConnectedDevices();
      if (deviceList.isEmpty()) {
         return BluetoothProfile.STATE_DISCONNECTED;
      } else {
         return mHeadsetClient.getConnectionState(deviceList.remove(0));
      }
      
   }
   return BluetoothProfile.STATE_DISCONNECTED;
}
//连接远程设备
public boolean connect(BluetoothDevice device) {
   if (null != mHeadsetClient) {
      return mHeadsetClient.connect(device);
   }
   Log.i(TAG,"connect mHeadsetClient == "+mHeadsetClient);
   return false;
}
//断开连接
public boolean disconnect(BluetoothDevice device) {
   if (null != mHeadsetClient) {
      return mHeadsetClient.disconnect(device);
   }
   Log.i(TAG, "disconnect mHeadsetClient == "+mHeadsetClient);
   return false;
}

BluetoothHeadsetClient控制声音通道

// Initiates a connection of audio channel.
public boolean connectAudio() {
   Log.d(TAG, "hangup clicked isHeadsetReady:" + isHeadSetProfileReady + ", mHeadset:" + mHeadsetClient);
   if (isHeadSetProfileReady && mHeadsetClient != null) {
      List<BluetoothDevice> deviceList = mHeadsetClient.getConnectedDevices();
      if (deviceList.isEmpty()) {
           return false;
        } else {
            setSpeakerPhoneOn(true);
            BluetoothDevice mDevice = deviceList.remove(0);
            return mHeadsetClient.connectAudio(mDevice);
        }
   } 
   return false;
}
// Disconnects audio channel.
public boolean disconnectAudio() {
   Log.d(TAG, "hangup clicked isHeadsetReady:" + isHeadSetProfileReady + ", mHeadset:" + mHeadsetClient);
   if (isHeadSetProfileReady && mHeadsetClient != null) {
      List<BluetoothDevice> deviceList = mHeadsetClient.getConnectedDevices();
      if (deviceList.isEmpty()) {
         return false;
        } else {
            setSpeakerPhoneOn(false);
            BluetoothDevice mDevice = deviceList.remove(0);
            return mHeadsetClient.disconnectAudio(mDevice);
        }
   } 
   return false;
}

BluetoothHeadsetClient电话

// 拨号
public void dial(String number) {
   Log.d(TAG, "dial clicked mIsProfileReady:" + isHeadSetProfileReady + ", mHeadsetClient:" + mHeadsetClient);
   if (!mAdapter.isEnabled() || mHeadsetClient == null) {
      ToastUtil.showToast(mContext, mContext.getResources().getString(R.string.bt_disable));
      return;
   }
   if (isHeadSetProfileReady && mHeadsetClient != null) {
      List<BluetoothDevice> deviceList = mHeadsetClient.getConnectedDevices();
           if (deviceList.isEmpty()) {
               ToastUtil.showToast(mContext, mContext.getResources().getString(R.string.text_tips_disconnected));
           }else {
               BluetoothDevice mDevice = deviceList.remove(0);
               setSpeakerPhoneOn(true);
               mHeadsetClient.dial(mDevice, number);
           }
   }
}
// 挂断所有电话
public void terminateCall(int callNumber) {
      Log.d(TAG, "terminate clicked isHeadsetReady:" + isHeadSetProfileReady + ", mHeadset:" + mHeadsetClient);
      if (isHeadSetProfileReady && mHeadsetClient != null) {
         List<BluetoothDevice> deviceList = mHeadsetClient.getConnectedDevices();
         if (deviceList.isEmpty()) {
              ToastUtil.showToast(mContext, mContext.getResources().getString(R.string.text_tips_disconnected));
           } else {
              setSpeakerPhoneOn(false);
              BluetoothDevice mDevice = deviceList.remove(0);
              List<BluetoothHeadsetClientCall> calls = mHeadsetClient.getCurrentCalls(mDevice);
              if (!calls.isEmpty()) {
                 BluetoothHeadsetClientCall call = calls.remove(callNumber);
                 mHeadsetClient.terminateCall(mDevice,call);
              }
           }
      }
   }
//接听来电
public void acceptCall(int flag) {
   Log.d(TAG, "hangup clicked isHeadsetReady:" + isHeadSetProfileReady + ", mHeadset:" + mHeadsetClient);
   if (isHeadSetProfileReady && mHeadsetClient != null) {
      List<BluetoothDevice> deviceList = mHeadsetClient.getConnectedDevices();
      if (deviceList.isEmpty()) {
           ToastUtil.showToast(mContext, mContext.getResources().getString(R.string.text_tips_disconnected));
        } else {
            setSpeakerPhoneOn(true);
            BluetoothDevice mDevice = deviceList.remove(0);
            mHeadsetClient.acceptCall(mDevice,flag);
        }
   }
}
//挂断来电
public void hangup() {
   Log.d(TAG, "hangup clicked isHeadsetReady:" + isHeadSetProfileReady + ", mHeadset:" + mHeadsetClient);
   if (isHeadSetProfileReady && mHeadsetClient != null) {
      List<BluetoothDevice> deviceList = mHeadsetClient.getConnectedDevices();
      if (deviceList.isEmpty()) {
           ToastUtil.showToast(mContext, mContext.getResources().getString(R.string.text_tips_disconnected));
        } else {
            setSpeakerPhoneOn(false);
            BluetoothDevice mDevice = deviceList.remove(0);
            mHeadsetClient.rejectCall(mDevice);
        }
   }
}
//发送DTMF
public void sendDTMF(byte code) {
   if (!mAdapter.isEnabled() || mHeadsetClient == null) {
      ToastUtil.showToast(mContext, mContext.getResources().getString(R.string.bt_disable));
      return;
   }
   Log.d(TAG, "sendDTMF() Enter. with" + code);
   List<BluetoothDevice> deviceList = mHeadsetClient.getConnectedDevices();
   if (deviceList.isEmpty()) {
      ToastUtil.showToast(mContext, mContext.getResources().getString(R.string.text_tips_disconnected));
   } else {
      BluetoothDevice mDevice = deviceList.remove(0);
      Log.d(TAG, "mConnStat is " + mConnStat);
      if (mConnStat == BluetoothHeadsetClientCall.CALL_STATE_ACTIVE) {
         mHeadsetClient.sendDTMF(mDevice, code);
      } else {
         Log.d(TAG, "mConnStat is not CALL_STATE_ACTIVE");
      }
   }
}
//三方ANSWER_AND_HOLD
bluetoothHeadsetClient.acceptCall(BluetoothDevice,BluetoothHeadsetClient.CALL_ACCEPT_HOLD);
//三方ANSWER_AND_TERMINATE
bluetoothHeadsetClient.acceptCall(BluetoothDevice,BluetoothHeadsetClient.CALL_ACCEPT_TERMINATE);
//获取信号强度
Bundle bundle = bluetoothHeadsetClient.getCurrentAgEvents(BluetoothDevice);
if (bundle != null && bundle.containsKey(BluetoothHeadsetClient.EXTRA_NETWORK_SIGNAL_STRENGTH))
{
    return bundle.getInt(BluetoothHeadsetClient.EXTRA_NETWORK_SIGNAL_STRENGTH);
}