如何在非活动类中使用WifiManager？

Question

我有两个类:其中一个是活动类,另一个是非活动类.我调用一个非活动类中的方法来返回mac Adress.

活动类:

public class Control extends Activity {
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    deneme d = new deneme(this); // i has tried (getApplicatonContext)
    String x = d.macadress();
    Toast.makeText(getApplicationContext(), x, Toast.LENGTH_LONG).show();
}}

和非活动类:

public class deneme {
Context mcontext ;
WifiManager wm;

public deneme(Context mcontext){
    this.mcontext = mcontext;
}

public String macadress(){
    wm = (WifiManager)mcontext.getSystemService(Context.WIFI_SERVICE);
    String m_szWLANMAC = wm.getConnectionInfo().getMacAddress();
    return m_szWLANMAC;

}}

但该方法返回null.我有权限ACCESS_WIFI_STATE.

Answer 1

    public class MainActivity extends Activity {

        @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        deneme d = new deneme(getApplicationContext()); 
  //  String x=d.wm.getConnectionInfo().getMacAddress();


      String x = d.macadress();
        Toast.makeText(getApplicationContext(), x, Toast.LENGTH_LONG).show();

    }


}
 class deneme {
Context mcontext ;
WifiManager wm;

public deneme(Context mcontext){
    this.mcontext = mcontext;
}

public String macadress(){
    wm = (WifiManager)mcontext.getSystemService(Context.WIFI_SERVICE);
    String m_szWLANMAC = wm.getConnectionInfo().getMacAddress();
    return m_szWLANMAC;

}}

我没有运行代码，但这就是它要做的