Android实现主动连接蓝牙耳机
在Android程序中可以实现自动扫描蓝牙、配对蓝牙、建立数据通道。蓝牙分不同类型，这篇文字只讨论如何与蓝牙耳机连接。
大致可以分三步：
一、扫描蓝牙设备：
1、注册并监听广播：
BluetoothAdapter.ACTION_DISCOVERY_STARTED
BluetoothDevice.ACTION_FOUND
BluetoothAdapter.ACTION_DISCOVERY_FINISHED
启动扫描：
BluetoothAdapter.getDefaultAdapter().startDiscovery();
对扫描的结果按类型进行筛选，只保留我们需要的蓝牙耳机：
if(device.getBluetoothClass().getDeviceClass() == BluetoothClass.Device.AUDIO_VIDEO_WEARABLE_HEADSET
|| device.getBluetoothClass().getDeviceClass() == BluetoothClass.Device.AUDIO_VIDEO_HANDSFREE){
//蓝牙耳机
}
二、配对指定的蓝牙设备：
这个跟配对普通蓝牙一样，方法如下：
public static boolean createBond(BluetoothDevice btDevice){
boolean result = false;
try{
Method m = btDevice.getClass().getDeclaredMethod("createBond",new Class[]{});
m.setAccessible(true);
Boolean originalResult = (Boolean) m.invoke(btDevice);
result = originalResult.booleanValue();
}catch(Exception ex){
}
return result;
}
等配对完成之后就是要建立数据连接；
三、建立数据连接：
if you SDK between 11 and 16.call a2dp.connectSink(btDevice) or a2dp.connect(btDevice)
private static IBluetoothA2dp getIBluetoothA2dp() {
IBluetoothA2dp ibta = null;
try {
final Class serviceManager = Class.forName("android.os.ServiceManager");
final Method getService = serviceManager.getDeclaredMethod("getService", String.class);
final IBinder iBinder = (IBinder) getService.invoke(null, "bluetooth_a2dp");
final Class iBluetoothA2dp = Class.forName("android.bluetooth.IBluetoothA2dp");
final Class[] declaredClasses = iBluetoothA2dp.getDeclaredClasses();
final Class c = declaredClasses[0];
final Method asInterface = c.getDeclaredMethod("asInterface", IBinder.class);
asInterface.setAccessible(true);
ibta = (IBluetoothA2dp) asInterface.invoke(null, iBinder);
} catch (final Exception e) {
Log.e("Error " + e.getMessage());
}
return ibta;
}
参考：/questions/8467178/working-around-a2dp-and-hfp-limitations-of-android-pre-honeycomb
如果API大于16需要用如下的方法：
private void initA2dpService(){
//Intent i = getExplicitIntent(mContext,new Intent(IBluetoothA2dp.class.getName()));//5.0以上系统需要显示intent
Intent i = new Intent(IBluetoothA2dp.class.getName());
boolean success = mContext.bindService(i, mConnection, Context.BIND_AUTO_CREATE);
if (success) {
} else {
}
}
public ServiceConnection mConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
try {
mA2dpService = IBluetoothA2dp.Stub.asInterface(service);
} catch (Exception e) {
e.printStackTrace();
}
}
@Override
public void onServiceDisconnected(ComponentName name) {
// TODO Auto-generated method stub
}
};
public Intent getExplicitIntent(Context context, Intent implicitIntent) {
// Retrieve all services that can match the given intent
PackageManager pm = context.getPackageManager();
List resolveInfo = pm.queryIntentServices(implicitIntent, 0);
// Make sure only one match was found
if (resolveInfo == null || resolveInfo.size() != 1) {
return null;
}
// Get component info and create ComponentName
ResolveInfo serviceInfo = resolveInfo.get(0);
String packageName = serviceInfo.serviceInfo.packageName;
String className = serviceInfo.serviceInfo.name;
ComponentName component = new ComponentName(packageName, className);
// Create a new intent. Use the old one for extras and such reuse
Intent explicitIntent = new Intent(implicitIntent);
// Set the component to be explicit
explicitIntent.setComponent(component);
return explicitIntent;
}
建立连接：mA2dpService.connect(device);
断开连接：mA2dpService.disconnect(device);
参考：/questions/14705167/how-connect-paired-bluetooth-a2dp-device-on-android-4-2-using-reflection
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