如何在Android中一次又一次地从wifi列表中选择相同的wifi运营商？

Question

在我的项目中我有一个Map.First我去Wifi路由器位置,我扫描wifi列表并选择Operator2并标记它.接下来我去另一个位置收集相同的Previous Operator2细节(不要),然后我去另一个位置再次重复.

我可以第一次选择Wifi Operator.Next时间我不知道如何锁定特定的先前选择的操作员详细信息并再次获取操作员详细信息.所以请帮我解决这个问题.

我的代码:

public class WifiReceiver extends BroadcastReceiver {

private WifiManager wifiManager;
private PlanMapperActivity viewerActivity;
private Context newContext;

private String operator;
private String macAddress;
private int signalStrength;
private String wifiMode;
private int frequency;
private String htMode;
private String security;
private int channelNumber;



private AlertDialog wifiAlertDialog;
private ListView  wifiListView;
private ProgressDialog progress;

private Boolean checkWifiSelected;
private Boolean checkServayStart;

private String operatorName;

List<ScanResult> wifiSRList;

private static final String WPA2 = "WPA2";
private static final String WEP = "WEP";
private static final String EAP = "EAP";
private static final String STORED_OPERATOR = "com.kenturf.wifiheatmap.SELECTED_OPERATOR";

private int requiredLevel;
private int ssidCount;

public WifiReceiver(Context ctx,PlanMapperActivity planMapper) {
    this.viewerActivity = planMapper;
    this.newContext = ctx;
}

public WifiReceiver(WifiManager myWifiManager,ProgressDialog wifiProgress,Boolean isWifiSelected,Boolean isSurveyStart) {
    this.wifiManager = myWifiManager;
    this.progress = wifiProgress;
    this.checkWifiSelected = isWifiSelected;
    this.checkServayStart = isSurveyStart;
}

@Override
public void onReceive(final Context context, Intent intent) {

    wifiSRList = wifiManager.getScanResults();

    if (wifiSRList.size() == 0) {
        Toast.makeText(context,"wifi List 0",Toast.LENGTH_SHORT).show();
    }

    if (checkWifiSelected) {
        LayoutInflater wifiLayout = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View wifiView = wifiLayout.inflate(R.layout.dialog_fragment_wifi,null);

        AlertDialog.Builder wifiDialog = new AlertDialog.Builder(context);
        wifiDialog.setCancelable(false);
        wifiDialog.setView(wifiView);

        wifiAlertDialog = wifiDialog.create();
        wifiListView = (ListView)wifiView.findViewById(R.id.user_wifi_detail);
    }


    Collections.sort(wifiSRList, new Comparator<ScanResult>() {
        @Override
        public int compare(ScanResult lhs, ScanResult rhs) {
            return (lhs.level > rhs.level ? -1 : (lhs.level == rhs.level ? 0 : 1));
        }
    });


    if (checkWifiSelected) {
        String[] wifiListString = new String[wifiSRList.size()];

        for (int i = 0; i < wifiSRList.size(); i++) {
            wifiListString[i] = (wifiSRList.get(i).SSID);
        }

        wifiListView.setAdapter(new ArrayAdapter<>(context, android.R.layout.simple_list_item_1, wifiListString));

        wifiAlertDialog.show();
        progress.dismiss();

        wifiListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                operator = wifiSRList.get(position).SSID;
                macAddress = wifiSRList.get(position).BSSID;
                signalStrength = wifiSRList.get(position).level;
                frequency = wifiSRList.get(position).frequency;

                final String cap = wifiSRList.get(position).capabilities;
                final String[] securityModes = {WEP, WPA2, EAP};
                for (int i = securityModes.length - 1; i >= 0; i--) {
                    if (cap.contains(securityModes[i])) {
                        security = securityModes[i];
                    }
                }

                setOperator(operator);
                GetSetClass.wifiOperator = operator;

                /* error start ..cannot resolved method getPreferences() */
                SharedPreferences sharedPref = context.getPreferences(Context.MODE_PRIVATE); // error line
                SharedPreferences.Editor editor = sharedPref.edit();
                editor.putString(STORED_OPERATOR, operator);
                editor.apply();
                /* error end */

                operatorName = operator;
                setMacAddress(macAddress);
                setSignalStrength(signalStrength);
                setFrequency(frequency);
                setSecurity(security);
                setChannelNumber(convertFrequencyToChannel(frequency));
                wifiAlertDialog.dismiss();

                checkWifiSelected = false;
            }
        });
    }

    if(checkServayStart) {
        /* error start ..cannot resolved method getPreferences()*/
        SharedPreferences shPref = context.getPreferences(Context.MODE_PRIVATE); // error line
        String savedOperator = shPref.getString(STORED_OPERATOR,null);

        Log.e("operator : ", "saved operator is : " + savedOperator);
        /* error end */

        if (wifiSRList != null) {
            ssidCount = wifiSRList.size();
            for(int i = wifiSRList.size() - 1; i >= 0; i--) {
                if (GetSetClass.wifiOperator.equals(wifiSRList.get(i).SSID)) {
                    String requiredOperator = wifiSRList.get(i).SSID;
                        requiredLevel = wifiSRList.get(i).level;
                        context.unregisterReceiver(this);
                    AlertDialog.Builder myBuilder = new AlertDialog.Builder(context);

                    setRequiredLevel(requiredLevel);

                    myBuilder.setTitle("Current Signal");
                    myBuilder.setMessage("Operator : " + requiredOperator + " \n\nSignal Strength : " + requiredLevel + " dBm");
                    myBuilder.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            dialog.dismiss();
                        }
                    });
                    myBuilder.show();
                } else {
                    Toast.makeText(context,"Operator Mismatch",Toast.LENGTH_SHORT).show();
                }
            }

            progress.dismiss();
        }
    }
}

public static int convertFrequencyToChannel(int freq) {
    if (freq >= 2412 && freq <= 2484) {
        return (freq - 2412) / 5 + 1;
    } else if (freq >= 5170 && freq <= 5825) {
        return (freq - 5170) / 5 + 34;
    } else {
        return -1;
    }
}
}

更新的答案:

private static final String STORED_FILE = "com.package.name.SELECTED_FILE";
private static final String STORED_OPERATOR = "com.package.name.SELECTED_OPERATOR";

将数据保存到SharedPreferences:

SharedPreferences sharedPref = context.getSharedPreferences(STORED_FILE,Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putString(STORED_OPERATOR, operator);
editor.apply();

从SharedPreferences获取数据:

SharedPreferences shPref = context.getSharedPreferences(STORED_FILE,Context.MODE_PRIVATE);
String savedOperator = shPref.getString(STORED_OPERATOR,null);

Log.e("operator : ", "saved operator is : " + savedOperator);

Answer 1

如果我理解正确的话，您需要的是一种机制来保留用户之前选择的 WiFi 网络（如果有）。

您可以使用 来实现这一点SharedPreferences。

在方法的开始onReceive，您查询应用程序的共享首选项以查找任何已保存的 WiFi SSID：

SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
String savedSsid = sharedPref.getString("saved_wifi_ssid", null);

如果savedSsid非空，则用户之前已经选择了WiFi，您可以跳过显示对话框：

if (savedSsid != null) {
    // Do whatever you need to do with the stored SSID.
    // Return from onReceive to avoid displaying your dialog.
    return;
}

您需要做的最后一件事是将选定的 WiFi SSID 存储为您的onItemClick：

wifi_SSID = wifiList.get(position).SSID;
// ... other code ...
SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putString("saved_wifi_ssid", wifi_SSID);
editor.commit();

有关 SharedPreferences 的更多信息，请参阅Android 开发人员指南。

更新

对于您的特定用例，即作为独立类驻留，您需要通过作为参数收到的实例BroadcastReceiver访问 SharedPreferences，如下所示：ContextonReceive

SharedPreferences sharedPref = context.getSharedPreferences("name_for_your_shared_preferences_file", Context.MODE_PRIVATE);

此行应替换两次出现的行：

SharedPreferences sharedPref = getActivity().getPreferences(Context.MODE_PRIVATE);

请参阅getSharedPreferences(String, int) 的文档。