我想在选项卡式活动中显示WiFi扫描的结果,带有2个选项卡'OM'&'OR' . 在'OM'选项卡中,我想列出SSID以OM&'OR' tab设备开头的设备,以SSID OR开头 . 我尝试了以下代码,它在活动 public class MainActivity extends AppCompatActivity {}
中运行良好 . 但是它不会在片段中给出任何结果(返回null) . 请查看以下代码,让我知道我在做什么错误 . 提前致谢 .
public static class OmFragment extends Fragment {
ListView listView;
private static WifiManager wifiManager;
private static WifiReceiver wifiReceiver;
private static List<ScanResult> wifiList;
ArrayList<String> arrayList = new ArrayList<>();
ArrayAdapter adapter;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_om_layout, container, false);
listView = (ListView) view.findViewById(R.id.wifiDeviceList);
wifiManager = (WifiManager) getActivity().getApplicationContext().getSystemService(Context.WIFI_SERVICE);
wifiReceiver = new WifiReceiver();
if (!wifiManager.isWifiEnabled()) {
if (wifiManager.setWifiEnabled(true)) {
Toast.makeText(getActivity(), "WIFI enabled.", Toast.LENGTH_SHORT).show();
getActivity().registerReceiver(wifiReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
wifiManager.startScan();
} else {
Toast.makeText(getActivity(), "Error in WiFi Initialization!!", Toast.LENGTH_SHORT).show();
}
} else if (wifiManager.isWifiEnabled()) {
getActivity().registerReceiver(wifiReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
wifiManager.startScan();
}
this.adapter = new ArrayAdapter<>(getActivity(), android.R.layout.simple_list_item_1, arrayList);
listView.setAdapter(this.adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
Toast.makeText(getActivity(), "Selected: " + listView.getItemAtPosition(position), Toast.LENGTH_LONG).show();
}
});
return view;
}
@Override
public void onDestroy() {
super.onDestroy();
try {
getActivity().unregisterReceiver(wifiReceiver);
} catch (Exception e) {
e.printStackTrace();
}
}
class WifiReceiver extends BroadcastReceiver {
public void onReceive(Context c, Intent intent) {
String action = intent.getAction();
if (action.equals(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)) {
Toast.makeText(getActivity(), "SCAN_RESULTS_AVAILABLE", Toast.LENGTH_SHORT).show();
wifiList = wifiManager.getScanResults();
Toast.makeText(getActivity(), "WiFi List: " + wifiList, Toast.LENGTH_SHORT).show();
if (wifiList.size() > 0) {
int TotalWifiDevices = wifiList.size();
Toast.makeText(getActivity(), "Number of Wifi connections : " + TotalWifiDevices, Toast.LENGTH_SHORT).show();
try {
while (TotalWifiDevices >= 0) {
TotalWifiDevices--;
arrayList.add(wifiList.get(TotalWifiDevices).SSID);
adapter.notifyDataSetChanged();
}
} catch (Exception e) {
Log.w("WiFi Exception: ", e);
}
} else {
Toast.makeText(getActivity(), "No Wifi found.", Toast.LENGTH_SHORT).show();
}
}
}
}
}
1 回答
我在Naugat上尝试App,我们需要提供以下权限
并且必须打开位置以及给予位置许可 . 代码现在正在运行 .