Androidで無線LANの状態の取得と設定は簡単に行える。

まず、manifestにおまじないを記述しておく。

<uses-permission android:name=&quot;android.permission.ACCESS_WIFI_STATE&quot;/>
<uses-permission android:name=&quot;android.permission.CHANGE_WIFI_STATE&quot;/>

取得のみであれば、CHANGE_WIFI_STATEは不要だ。コードは単純で、

WifiManager wifi;

public void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	wifi = (WifiManager)getSystemService(WIFI_SERVICE);
}

public boolean checkWifi() {
   	return (wifi.isWifiEnabled());
}

public void setWifi(boolean set){
	wifi.setWifiEnabled(set);
}

WiFiの状態は変化するので、状態に変化があれば取得したい場合、BroadcastReceiverを登録しておく。

@Override
protected void onResume() {
	super.onResume();
	IntentFilter filter = new IntentFilter();
	filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
	registerReceiver(mBroadcastReceiver, filter);
}

@Override
protected void onPause() {
	super.onPause();
	unregisterReceiver(mBroadcastReceiver);
}

private BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
	@Override
	public void onReceive(Context context, Intent intent) {
		String action = intent.getAction();
		if (action.equals(WifiManager.WIFI_STATE_CHANGED_ACTION)) {
			int extraWifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE , WifiManager.WIFI_STATE_UNKNOWN);

			if (extraWifiState == WifiManager.WIFI_STATE_DISABLED){
    	    }
			else if (extraWifiState == WifiManager.WIFI_STATE_ENABLED){
			}
		}
	}
};