Android Bluetooth打开关闭

mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (mBluetoothAdapter == null) {
Toast.makeText(this, "不支持蓝牙", Toast.LENGTH_SHORT).show();
} else if (!mBluetoothAdapter.isEnabled()) {
Intent enableBTIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBTIntent, REQUEST_ENABLE_BT);
}

private BroadcastReceiver receiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, 0);
switch (state) {
case BluetoothAdapter.STATE_TURNING_ON:
Toast.makeText(MainActivity.this, "Bluetooth正在打开", Toast.LENGTH_SHORT).show();
break;
case BluetoothAdapter.STATE_ON:
Toast.makeText(MainActivity.this, "Bluetooth已打开", Toast.LENGTH_SHORT).show();
break;
case BluetoothAdapter.STATE_TURNING_OFF:
Toast.makeText(MainActivity.this, "Bluetooth正在关闭", Toast.LENGTH_SHORT).show();
break;
case BluetoothAdapter.STATE_OFF:
Toast.makeText(MainActivity.this, "Bluetooth已关闭", Toast.LENGTH_SHORT).show();
break;
}
}
};

@Override
protected void onResume() {
super.onResume();
registerReceiver(receiver, new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED));
}

@Override
protected void onStop() {
super.onStop();
unregisterReceiver(receiver);
}