java - 一旦 Android 应用程序检测到特定的 Wi-Fi 网络，就会触发一些代码

Question

我正在开发一个 Android 应用程序。要使此应用正常运行，需要始终启用 Wi-Fi。由于启用了 Wi-Fi，它将继续扫描可用网络。

我希望在 Wi-Fi 连接到特定网络后立即调用某些函数。我如何实现这一点？

我已经写了下面的代码，但它只工作了一次，我该如何连续扫描网络？

ConnectivityManager connec = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
                      NetworkInfo wifi = connec.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
                      if(wifi.isConnected()){
                          final WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
                            final WifiInfo connectionInfo = wifiManager.getConnectionInfo();
                            if (connectionInfo != null && !(connectionInfo.getSSID().equals(""))) {
                              String ssid = connectionInfo.getSSID();
                            }
                          Log.i("wifi", "connected");
                      }
                      else{
                          Log.i("wifi", "not connected");
                      }

Answer 1

跟着步骤做个把戏

1) 创建NetworkChangeReceiver

public class NetworkChangeReceiver extends BroadcastReceiver {

    public static boolean isWifiConnected = true;
    public static final String tag = "NETWORKCHANGERECEIVER";

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

        ConnectivityManager connec = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo wifi = connec.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
        if (wifi.isConnected()) {
            final WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
            final WifiInfo connectionInfo = wifiManager.getConnectionInfo();
            if (connectionInfo != null && !(connectionInfo.getSSID().equals(""))) {
                String ssid = connectionInfo.getSSID();
            }
            isWifiConnected = true;
            Log.i("wifi", "connected");
        } else {
            Log.i("wifi", "not connected");
            isWifiConnected = false;
        }
    }
}

2) 将此行添加到 Manifest.xml

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

    <receiver android:name="com.df.src.NetworkChangeReceiver" >
                <intent-filter>
                    <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
                </intent-filter>
            </receiver>