<!-- 以下是使用wifi访问网络所需要的权限 -->

<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>

<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>

 

 

public class WifiActivity extends Activity {    /** Called when the activity is first created. */    private Button startButton = null;    private Button stopButton = null;    private Button checkButton = null;    private WifiManager wifiManager = null;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        startButton = (Button)findViewById(R.id.startWifi);        stopButton = (Button)findViewById(R.id.stopWifi);        checkButton = (Button)findViewById(R.id.checkWifi);        startButton.setOnClickListener(new StartWifiListener());        stopButton.setOnClickListener(new StopWifiListener());        checkButton.setOnClickListener(new CheckWifiListener());    }    class StartWifiListener implements OnClickListener{        @Override        public void onClick(View v) {            wifiManager = (WifiManager)WifiActivity.this.getSystemService(Context.WIFI_SERVICE);            wifiManager.setWifiEnabled(true);            System.out.println("wifi state --->"   wifiManager.getWifiState());            Toast.makeText(WifiActivity.this, "当前Wifi网卡状态为"   wifiManager.getWifiState(), Toast.LENGTH_SHORT).show();        }    }    class StopWifiListener implements OnClickListener{        @Override        public void onClick(View arg0) {            // TODO Auto-generated method stub            wifiManager = (WifiManager)WifiActivity.this.getSystemService(Context.WIFI_SERVICE);            wifiManager.setWifiEnabled(false);            System.out.println("wifi state --->"   wifiManager.getWifiState());            Toast.makeText(WifiActivity.this, "当前Wifi网卡状态为"   wifiManager.getWifiState(), Toast.LENGTH_SHORT).show();        }        }        class CheckWifiListener implements OnClickListener{        @Override        public void onClick(View v) {            wifiManager = (WifiManager)WifiActivity.this.getSystemService(Context.WIFI_SERVICE);            System.out.println("wifi state --->"   wifiManager.getWifiState());            Toast.makeText(WifiActivity.this, "当前Wifi网卡状态为"   wifiManager.getWifiState(), Toast.LENGTH_SHORT).show();        }            }}