2

检查是否存在有效的 WiFi 连接是没有问题的。但是如何确保只有这个 WiFi 连接用于网络访问？

假设以下场景：

  • 我检查是否存在有效的 WiFi 连接（我可能会验证是否存在有效的 Internet 连接）
  • 现在这个 WiFi 连接被中断了
  • 我开始通过网络传输数据，现在使用移动连接，因为 WiFi 最近死了

我怎样才能避免这种情况？

4

3 回答 3

3

检查是否存在 WiFi 连接：

ConnectivityManager connManager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
NetworkInfo mWifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);

if (mWifi.isConnected()) {
    // Do whatever
}

Source，或使用此代码段：

private static final String DEBUG_TAG = "NetworkStatusExample";
...      
ConnectivityManager connMgr = (ConnectivityManager) 
        getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI); 
boolean isWifiConn = networkInfo.isConnected();
networkInfo = connMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE);
boolean isMobileConn = networkInfo.isConnected();
Log.d(DEBUG_TAG, "Wifi connected: " + isWifiConn);
Log.d(DEBUG_TAG, "Mobile connected: " + isMobileConn);

添加监听器以检查 WiFi 是否仍处于启用状态：

public class NetworkReceiver extends BroadcastReceiver {   

@Override
public void onReceive(Context context, Intent intent) {
    ConnectivityManager conn =  (ConnectivityManager)
        context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = conn.getActiveNetworkInfo();

    // Checks the user prefs and the network connection. Based on the result, decides whether
    // to refresh the display or keep the current display.
    // If the userpref is Wi-Fi only, checks to see if the device has a Wi-Fi connection.
    if (WIFI.equals(sPref) && networkInfo != null && networkInfo.getType() == ConnectivityManager.TYPE_WIFI) {
        // If device has its Wi-Fi connection, sets refreshDisplay
        // to true. This causes the display to be refreshed when the user
        // returns to the app.
        refreshDisplay = true;
        Toast.makeText(context, R.string.wifi_connected, Toast.LENGTH_SHORT).show();

    // If the setting is ANY network and there is a network connection
    // (which by process of elimination would be mobile), sets refreshDisplay to true.
    } else if (ANY.equals(sPref) && networkInfo != null) {
        refreshDisplay = true;

    // Otherwise, the app can't download content--either because there is no network
    // connection (mobile or Wi-Fi), or because the pref setting is WIFI, and there 
    // is no Wi-Fi connection.
    // Sets refreshDisplay to false.
    } else {
        refreshDisplay = false;
        Toast.makeText(context, R.string.lost_connection, Toast.LENGTH_SHORT).show();
    }
}

请阅读管理网络使用以获得详细的解决方案

于 2012-12-10T18:25:08.217 回答
0

您可以添加广播接收器以进行网络更改。因此，每当 wifi 中断时，您都会收到通知，您可以根据需要处理这种情况。您可以在以下链接中找到更多详细信息http://developer.android.com/training/basics/network-ops/managing.html

于 2012-12-10T18:27:47.817 回答
0

您可以通过这种方法检查wifi是否中断？

ConnectivityManager networkManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = networkManager.getActiveNetworkInfo();
NetworkInfo wifi = networkManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (wifi.isAvailable() && wifi.isConnected()) {
     return true;
}else {
     return false;
}

您可以将广播接收器添加到 lsten 以进行网络更改，您可以将此方法添加到 onReceive() 方法中，并检查它，如果网络发生变化，您将在 onReceive() 上收到通知，然后您可以根据需要处理任何您想要的

于 2012-12-10T18:44:58.870 回答