如何在android中获取API级别7的蓝牙连接状态？

在我的android项目中，我的两台设备是成对的。我想通过蓝牙将文件从一台设备发送到另一台设备，当自动或手动接收到该文件时，该设备上的我的应用程序需要读取该文件并根据该文件执行一些操作

我已经创建了一个服务，它的OnCreate方法是为连接注册一个广播侦听器。此服务是在我的主要活动的OnCreate方法中启动的。因此，即使我的应用程序不在前端，这个广播接收器也会读取文件并执行所需的操作。首先，这是正确的方法吗？如果是，请告诉我怎么做

下面是我注册广播接收器的服务文件。当我运行这个代码并接收文件时，广播接收器的OnReceive并没有被调用

package com.android;

import android.app.Service;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;

public class FileReceiver extends Service {

    private static final String ACTION = "android.bluetooth.adapter.action.CONNECTION_STATE_CHANGED";

//    private BroadcastReceiver   BT_CONNECTION_BCAST_Receiver;
@Override
public IBinder onBind(Intent arg0) {
    return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    Log.i("LocalService", "Received start id " + startId + ": " + intent);
    // We want this service to continue running until it is explicitly
    // stopped, so return sticky.
    return START_STICKY;
}

@Override
public void onCreate() {
    super.onCreate();

    final IntentFilter theFilter = new IntentFilter();
    theFilter.addAction(ACTION);

    Log.i("LocalService", "On created ");




    // Registers the receiver so that your service will listen for broadcasts
    this.registerReceiver(this.btReceiver_Receiver, theFilter);
}

private final BroadcastReceiver btReceiver_Receiver = new BroadcastReceiver() {

    @Override
    public void onReceive(Context context, Intent intent) {
        // Do whatever you need it to do when it receives the broadcast
        // Example show a Toast message...
        String action = intent.getAction();
        BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
        Log.i("BT_Connection", "Inside Receiver");

        if (BluetoothDevice.ACTION_FOUND.equals(action)) {
            Log.i("BT_Connection", "Device Found");
         }

        if (BluetoothDevice.ACTION_ACL_CONNECTED.equals(action)) 
        {
            Log.i("BT_Connection", "On BT Connection");

        }


        Log.i("LocalService", "On Broadcast Receiver");

        showSuccessfulBroadcast();
    }
};
@Override
public void onDestroy() {
    super.onDestroy();
    Log.i("LocalService", "On Being Destroyed!!");

    // Do not forget to unregister the receiver!!!
    this.unregisterReceiver(this.btReceiver_Receiver);
}

private void showSuccessfulBroadcast() {
    Toast.makeText(this, "Broadcast Successful!!!", Toast.LENGTH_LONG).show();
}
}