用于CONNECTIVITY_ACTION的BroadcastReceiver始终在intent.getExtras()中返回null

Question

我试图从CONNECTIVITY_ACTION接收BroadcastMessages:

    // register BroadcastReceiver on network state changes
    final IntentFilter mIFNetwork = new IntentFilter();
    mIFNetwork.addAction(android.net.ConnectivityManager.CONNECTIVITY_ACTION); //"android.net.conn.CONNECTIVITY_CHANGE"
    registerReceiver(mIRNetwork, mIFNetwork);

和接收者是:

private BroadcastReceiver mIRNetwork = new BroadcastReceiver() {
    @Override
    public void onReceive(final Context context, final Intent intent) {

        android.util.Log.i(TAG,"mIRNetwork: Network State Received: "+intent.getAction());
        Bundle extras = intent.getExtras();
        if (extras!=null){
                android.util.Log.i(TAG,"mIRNetwork: ACTION_BACKGROUND_DATA_SETTING_CHANGED: "+extras.getString(ConnectivityManager.ACTION_BACKGROUND_DATA_SETTING_CHANGED));
                android.util.Log.i(TAG,"mIRNetwork: CONNECTIVITY_ACTION: "+extras.getString(ConnectivityManager.CONNECTIVITY_ACTION));
                android.util.Log.i(TAG,"mIRNetwork: EXTRA_EXTRA_INFO: "+extras.getString(ConnectivityManager.EXTRA_EXTRA_INFO));
                android.util.Log.i(TAG,"mIRNetwork: EXTRA_NO_CONNECTIVITY: "+extras.getString(ConnectivityManager.EXTRA_NO_CONNECTIVITY));
                android.util.Log.i(TAG,"mIRNetwork: EXTRA_REASON: "+extras.getString(ConnectivityManager.EXTRA_REASON));

            }
        }

总之,额外的东西总是空的.我认为,如果我松散WiFi连接,我应该得到EXTRA_NO_CONNECTIVITY(因为它是互联网的唯一途径)或至少从列表中的东西.但没有运气.如果我断开我的WiFi AP接收器得到他的消息,但有额外的空.当我再次打开我的WiFi接收器发射但没有额外的时候......为什么会这样？如何知道该应用程序丢失了任何网络连接？我想是这样的.

Answer 1

您无法获得额外的收益,但您可以通过这种方式获取数据

private class ConnectivityBroadcastReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        boolean noConnectivity = intent.getBooleanExtra(ConnectivityManager
                .EXTRA_NO_CONNECTIVITY, false);
        NetworkInfo info1 = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager
                .EXTRA_NETWORK_INFO);
        NetworkInfo info2 = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager
                .EXTRA_OTHER_NETWORK_INFO);
        String reason = intent.getStringExtra(ConnectivityManager.EXTRA_REASON);
        boolean failOver = intent.getBooleanExtra(ConnectivityManager.EXTRA_IS_FAILOVER, false);
        Log.d("MY_TAG", "onReceive(): mNetworkInfo=" + info1 + " mOtherNetworkInfo = " +
                (info2 == null ? "[none]" : info2 + " noConn=" + noConnectivity));
    }
}

有关详细信息,请参阅此

http://code.google.com/p/androidwisprclient/source/browse/trunk/src/com/joan/pruebas/NetworkConnectivityListener.java?r=2

Answer 2

Dharmendras 的回答很好。但是，请注意，EXTRA_NETWORK_INFO现在已弃用（自 Api Level 14 起），Android 文档说明如下：

由于 NetworkInfo 可能因 UID 而异，因此应用程序应始终通过getActiveNetworkInfo().

这实际上使我们的事情变得非常容易。您可以重复使用之前可能进行的连接检查并执行以下操作：

private class ConnectivityBroadcastReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        unregisterReceiver(this)
        checkConnection();
    }
}

private void checkConnection() {
    ConnectivityManager cm = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
    if (cm.getActiveNetworkInfo() != null && cm.getActiveNetworkInfo()
            .isConnectedOrConnecting()) {
        // do something
    }
}

_{假设您在注册广播的活动中。}

这也有一个额外的好处，即遵循最佳实践，尽可能简短地只收听连接广播，这里概述:)