我正在制作一个应用程序，列出所有可用的无线网络，并连接到用户选择的一个

Question

我正在尝试构建一个扫描可用wifi连接的应用程序，并在列表视图中列出它们。用户可以选择一个并连接到wifi。我的代码似乎不起作用。我在清单中添加了以下权限：

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

这是主要活动：

public class MainActivity extends ListActivity {
    WifiManager mainWifiObj;
    WifiScanReceiver wifiScanReceiver;
    ListView list;
    String wifiList[];
    EditText pass;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        list=getListView();
        mainWifiObj = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        wifiScanReceiver = new WifiScanReceiver();
        mainWifiObj.startScan();

        // listening to single list item on click
        list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                // selected item
                String ssid = ((TextView) view).getText().toString();
                connectToWifi(ssid);
                Toast.makeText(MainActivity.this,"Wifi SSID : "+ssid,Toast.LENGTH_SHORT).show();

            }
        });
    }

    protected void onPause() {
        unregisterReceiver(wifiScanReceiver);
        super.onPause();
    }

    protected void onResume() {
        registerReceiver(wifiScanReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
        super.onResume();
    }
    class WifiScanReceiver extends BroadcastReceiver {
        @SuppressLint("UseValueOf")
        public void onReceive(Context c, Intent intent) {
            List<ScanResult> wifiScanList = mainWifiObj.getScanResults();
            wifiList = new String[wifiScanList.size()];
            for(int i = 0; i < wifiScanList.size(); i++){
                wifiList[i] = ((wifiScanList.get(i)).SSID);
            }
            String filtered[] = new String[wifiScanList.size()];
            int counter = 0;
            for (String eachWifi : wifiList) {
                String[] temp = eachWifi.split(",");

                filtered[counter] = temp[0].substring(5).trim();//+"\n" + temp[2].substring(12).trim()+"\n" +temp[3].substring(6).trim();//0->SSID, 2->Key Management 3-> Strength

                counter++;

            }
            list.setAdapter(new ArrayAdapter<String>(getApplicationContext(),R.layout.list_item,R.id.label, filtered));


        }
    }

    private void finallyConnect(String networkPass, String networkSSID) {
        WifiConfiguration wifiConfig = new WifiConfiguration();
        wifiConfig.SSID = String.format("\"%s\"", networkSSID);
        wifiConfig.preSharedKey = String.format("\"%s\"", networkPass);

        // remember id
        int netId = mainWifiObj.addNetwork(wifiConfig);
        mainWifiObj.disconnect();
        mainWifiObj.enableNetwork(netId, true);
        mainWifiObj.reconnect();

        WifiConfiguration conf = new WifiConfiguration();
        conf.SSID = "\"\"" + networkSSID + "\"\"";
        conf.preSharedKey = "\"" + networkPass + "\"";
        mainWifiObj.addNetwork(conf);
    }

    private void connectToWifi(final String wifiSSID) {
        final Dialog dialog = new Dialog(this);
        dialog.setContentView(R.layout.connect);
        dialog.setTitle("Connect to Network");
        TextView textSSID = (TextView) dialog.findViewById(R.id.textSSID1);

        Button dialogButton = (Button) dialog.findViewById(R.id.okButton);
        pass = (EditText) dialog.findViewById(R.id.textPassword);
        textSSID.setText(wifiSSID);

        // if button is clicked, connect to the network;
        dialogButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String checkPassword = pass.getText().toString();
                finallyConnect(checkPassword, wifiSSID);
                dialog.dismiss();
            }
        });
        dialog.show();
    }

}

通过调试代码，我发现即使在调用getScanResults之后，wifilist也不包含单个值。我甚至试图找到各种线程中显示的代码，似乎没有列出无线网络。如何使此代码有效？

Answer 1

从Android 6.0开始，您还需要位置权限才能获得wifi scanResult。请参阅documentation。