android蓝牙打开关闭过程监听

在打开蓝牙时，一般蓝牙的打开都需要一个过程，而且有些机型还会打开失败，所以就要监测蓝牙的打开过程，下面给出代码：

创建一个BluetoothListenerReceiver.
public class BluetoothListenerReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        switch (intent.getAction()) {
            case BluetoothAdapter.ACTION_STATE_CHANGED:
                int blueState = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, 0);
                switch (blueState) {
                    case BluetoothAdapter.STATE_TURNING_ON:
                        Log.e("onReceive---------蓝牙正在打开中");
                     
                        break;
                    case BluetoothAdapter.STATE_ON:
                        Log.e("onReceive---------蓝牙已经打开");
                  
                        break;
                    case BluetoothAdapter.STATE_TURNING_OFF:
                        Log.e("onReceive---------蓝牙正在关闭中");
                    
                        break;
                    case BluetoothAdapter.STATE_OFF:
                        Log.e("onReceive---------蓝牙已经关闭");
                      
                        break;
                }
                break;
        }

    }
}

在activity或者fragment中注册receiver

private BluetoothListenerReceiver receiver;

@Override
public void onCreate(@Nullable Bundle savedInstanceState, Context mContext) {
  receiver = new BluetoothListenerReceiver(); 
  mContext.registerReceiver(receiver,makeFilter());
}
private IntentFilter makeFilter() {
    IntentFilter filter = new IntentFilter();
    filter.addAction(BluetoothAdapter.ACTION_STATE_CHANGED);
    return filter;
}

这样就可以监听蓝牙的打开和关闭过程了。