android - 使用 BroadcastReceiver 在 Android 中获取断开连接的 WiFi 网络的 SSID？

Question

我有以下 BroadcastRecevier:

public class WiFiConnectionEventsReceiver extends BroadcastReceiver {

    private static final String TAG = WiFiConnectionEventsReceiver.class.getSimpleName();

    @Override
    public void onReceive(Context context, @NonNull Intent intent) {
        Log.v(TAG, "action: " + intent.getAction());
        Log.v(TAG, "component: " + intent.getComponent());
        Bundle extras = intent.getExtras();
        if (extras != null) {
            for (String key : extras.keySet()) {
                Log.v(TAG, "key [" + key + "]: " +
                        extras.get(key));
            }
        } else {
            Log.v(TAG, "no extras");
        }

        ConnectivityManager conMan = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = conMan.getActiveNetworkInfo();
        if (netInfo != null && netInfo.getType() == ConnectivityManager.TYPE_WIFI) {
            Log.d("NetworkInfo", "Have Wifi Connection");
            Log.d("NetworkInfo", netInfo.getExtraInfo());
            Log.d("NetworkInfo", netInfo.getTypeName());
        }
        else {
            Log.d("NetworkInfo", "Don't have Wifi Connection");
            Log.d("NetworkInfo", netInfo.getExtraInfo());
            Log.d("NetworkInfo", netInfo.getTypeName());
        }

        WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
        Log.d("WifiInfo",  wifiManager.getConnectionInfo().toString());
    }
}

它接收网络连接和断开事件。

当它连接到 WiFi 网络时，我可以轻松获取网络的 SSID。

但我也希望能够在网络断开连接时获取 WiFi 网络的 SSID(无需存储以前连接的网络，然后以这种方式匹配它们等)。这可能吗？

WiFi 连接时的日志:

V/WiFiConnectionEventsReceiver: action: android.net.conn.CONNECTIVITY_CHANGE
V/WiFiConnectionEventsReceiver: component: ComponentInfo{com.example.test/com.example.test.WiFiConnectionEventsReceiver}
V/WiFiConnectionEventsReceiver: key [networkInfo]: [type: WIFI[], state: CONNECTED/CONNECTED, reason: (unspecified), extra: "SKY123”, roaming: false, failover: false, isAvailable: true]
V/WiFiConnectionEventsReceiver: key [networkType]: 1
V/WiFiConnectionEventsReceiver: key [inetCondition]: 100
V/WiFiConnectionEventsReceiver: key [extraInfo]: "SKY123”
D/NetworkInfo: Have Wifi Connection
D/NetworkInfo: "SKY123”
D/NetworkInfo: WIFI
D/WifiInfo: SSID: SKY123, BSSID: 10:40:03:ad:6x:c9, MAC: 02:00:00:00:00:00, Supplicant state: COMPLETED, RSSI: -79, Link speed: 43Mbps, Frequency: 2412MHz, Net ID: 1, Metered hint: false, score: 60

WiFi 断开连接时的日志(注意未知的 SSID):

V/WiFiConnectionEventsReceiver: action: android.net.conn.CONNECTIVITY_CHANGE
V/WiFiConnectionEventsReceiver: component: ComponentInfo{com.example.test/com.example.test.WiFiConnectionEventsReceiver}
V/WiFiConnectionEventsReceiver: key [networkInfo]: [type: WIFI[], state: DISCONNECTED/DISCONNECTED, reason: (unspecified), extra: <unknown ssid>, roaming: false, failover: false, isAvailable: true]
V/WiFiConnectionEventsReceiver: key [networkType]: 1
V/WiFiConnectionEventsReceiver: key [inetCondition]: 0
V/WiFiConnectionEventsReceiver: key [extraInfo]: <unknown ssid>
V/WiFiConnectionEventsReceiver: key [noConnectivity]: true
D/NetworkInfo: Don't have Wifi Connection
D/NetworkInfo: id
D/NetworkInfo: MOBILE
D/WifiInfo: SSID: <unknown ssid>, BSSID: <none>, MAC: 02:00:00:00:00:00, Supplicant state: COMPLETED, RSSI: -127, Link speed: -1Mbps, Frequency: -1MHz, Net ID: -1, Metered hint: false, score: 0

我想要此信息的原因是我希望能够跟踪用户在每个网络上的 WiFi 使用情况 - 连接和断开连接的时间。

没有断开网络的 SSID，我能想到的唯一方法是:

if (WiFi network ABC disconnected)
  if (if previous stored connection for WiFi network ABC has no disconnection time)
      set WiFI network ABC disconnection time to now

但是，上述方法感觉不稳定，例如，如果由于某种原因错过了 WiFi 断开连接事件等

Answer 1

您绝对可以做到这一点，方法是使用与您尝试过的方法不同的方法。

1. 你需要注册一个监听WifiManager.SCAN_RESULTS_AVAILABLE_ACTION的接收器.
2. 每当您进行 wifi 扫描时，都会使用扫描结果调用此接收器，在这些结果中您将拥有任何可用的路由器 ssid(无论其连接状态如何)
3. 然后，您需要将您在代码中找到的断开连接的 wifi 与扫描列表相匹配。

将此权限添加到您的 list 中，并且不要忘记，如果您使用的是 marshmallow，request permission for the location .

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

这是 MainActivty，结果在广播接收器上接收。

public class MainActivity extends AppCompatActivity {

    private WifiManager mWifiManager;
    private List<ScanResult> mScanResults;

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

        mWifiManager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        if (mWifiManager.isWifiEnabled() ||
                (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2 && mWifiManager.isScanAlwaysAvailable())) {
            registerReceiver(mReceiver, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
        }
    }

    private BroadcastReceiver mReceiver = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (action.equalsIgnoreCase(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)) {
                mScanResults = mWifiManager.getScanResults();
                for (ScanResult result : mScanResults) {
                    Log.i(getClass().getSimpleName(), "wifi Ssid : " + result.SSID);
                }
            }
        }
    };

    @Override
    protected void onDestroy() {
        try {
            unregisterReceiver(mReceiver);
        } catch (Exception e) {
            e.printStackTrace();
        }
        super.onDestroy();
    }
}