7

我的应用程序的部分功能是扫描并显示 WiFi 接入点列表,然后连接到用户选择的接入点。我有这个功能工作。现在,我还希望在连接“通过”时得到通知。这应该很简单,但我发现自己绊倒了。

我已经阅读了 SO 这里的各种帖子,它们都提到注册WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTIONor WifiManager.WIFI_STATE_CHANGED_ACTION。但是,这些都不适合我。任何人都可以在此代码中发现任何错误吗?(我省略了进行扫描的部分)

预期行为:一旦连接成功(即,当我在通知栏上看到“已连接”图标时),应该会收到广播并且应该看到 toast。

观察到的行为:当应用程序第一次启动时接收到广播,每当我切换回它时(即,每当onResume()被调用;或者我怀疑,每当我注册意图时)

public class WifiScanActivity extends Activity {

    WifiManager mainWifi;
    WifiReceiver mWifiReceiver;
    IntentFilter mIntentFilter;
    private final static String TAG = "WifiScanActivity";
    public static final String INTENT_FOR_WIFI_CONNECTED =
            WifiManager.WIFI_STATE_CHANGED_ACTION;
    // public static final String INTENT_FOR_WIFI_CONNECTED =
    // WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mainWifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
        mWifiReceiver = new WifiReceiver();
        mIntentFilter = new IntentFilter();
        mIntentFilter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
        mIntentFilter.addAction(INTENT_FOR_WIFI_CONNECTED);
        registerReceiver(mWifiReceiver, mIntentFilter);
        mainWifi.startScan();
    }

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

    protected void onResume() {
        registerReceiver(mWifiReceiver, mIntentFilter);
        super.onResume();
    }

    class WifiReceiver extends BroadcastReceiver {

        public void onReceive(Context c, Intent intent) {
            Log.d(TAG,
                "In WifiReceiver: Broadcast Received = " + intent.getAction());
            if (WifiManager.SCAN_RESULTS_AVAILABLE_ACTION.equals(intent
                .getAction())) {
                // Display the ListView and connect to the selected AP
            } else if (INTENT_FOR_WIFI_CONNECTED.equals(intent.getAction())) {
                if (WifiManager.WIFI_STATE_ENABLED == intent.getIntExtra(
                    WifiManager.EXTRA_WIFI_STATE, 0)) {
                    displayNetworkInfo();
                }
                /*if(true == intent.getBooleanExtra(
                 * WifiManager.EXTRA_SUPPLICANT_CONNECTED, false)){
                 *  displayNetworkInfo();
                }*/
            }
        }
    }

    private void displayNetworkInfo() {
        WifiInfo wifiInfo = mainWifi.getConnectionInfo();
        String ssid = wifiInfo.getSSID();
        int ip = wifiInfo.getIpAddress();
        String message = "Connection established.\nSSID = " + ssid
            + "; IP Address = " + Helper.displayIpAddress(ip);
        Log.d(TAG, message);
        Toast.makeText(this, message, Toast.LENGTH_LONG).show();
    }
}

如果我取消注释 WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION 的代码,我根本看不到正在接收广播。

注意:我知道连接成功,因为我在 Android 的 wifi 设置屏幕中看到了状态。

4

3 回答 3

23

好的,我想通了。事实证明我注册的是错误的意图。我应该使用 WifiManager.NETWORK_STATE_CHANGED_ACTION.

以下是相关代码部分的片段:

mIntentFilter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION) ;
mIntentFilter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);


public void onReceive(Context c, Intent intent) {

if (WifiManager.NETWORK_STATE_CHANGED_ACTION.equals(intent.getAction())) {

    NetworkInfo nwInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
    if(NetworkInfo.State.CONNECTED.equals(nwInfo.getState())){//This implies the WiFi connection is through
        displayNetworkInfo();
    }
}
于 2011-07-19T01:54:27.390 回答
0

在将这些权限添加到清单以检测广播后,我能够检测到:

<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/> 
于 2016-12-22T07:31:31.443 回答
-1

要在更改状态后获取广播,请参阅

于 2011-07-06T11:49:56.370 回答