[Android] 網路狀態 Network status listener/receiver

public class NetworkConnectionChangeReceiver extends BroadcastReceiver {
  private static final String TAG = NetworkConnectionChangeReceiver.class.getSimpleName();
  private Context mContext;

  @Override
  public void onReceive(Context context, Intent intent) {
    mContext = context;
    
    ConnectivityManager connectivityManager = (ConnectivityManager) context
        .getSystemService(Context.CONNECTIVITY_SERVICE);
    
    NetworkInfo activeNetInfo = connectivityManager.getActiveNetworkInfo();
    NetworkInfo mobileNetInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
    NetworkInfo wifiNetInfo = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
    
    if(activeNetInfo != null) {
      Toast.makeText(context, "Active Network Type : " + activeNetInfo.getTypeName(), Toast.LENGTH_SHORT).show();
      Log.e(TAG, "activeNetInfo.isAvailable(): " + activeNetInfo.isAvailable());
      Log.e(TAG, "activeNetInfo.isConnected()(): " + activeNetInfo.isConnected());
    }
    if(mobileNetInfo != null) {
      Toast.makeText(context, "Mobile Network Type : " + mobileNetInfo.getTypeName(), Toast.LENGTH_SHORT).show();
      Log.e(TAG, "mobNetInfo.isAvailable(): " + mobileNetInfo.isAvailable());
      Log.e(TAG, "mobNetInfo.isConnected()(): " + mobileNetInfo.isConnected());
    }
    if(wifiNetInfo != null) {
      Toast.makeText(context, "Wifi Network Type : " + wifiNetInfo.getTypeName(), Toast.LENGTH_SHORT).show();
      Log.e(TAG, "wifiNetInfo.isAvailable(): " + wifiNetInfo.isAvailable());
      Log.e(TAG, "wifiNetInfo.isConnected()(): " + wifiNetInfo.isConnected());
    }
  }
}

設成broadcast receiver是為了
在這個app中，當網路狀態一改變就會知道。

在AndroidManifest.xml裡加上

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

<receiver android:name="com.example.test.receiver.NetworkConnectionChangeReceiver">
    <intent-filter>
        <action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
    </intent-filter>
</receiver>