如何检测Android中何时建立WIFI连接？

Question

我需要检测何时通过WIFI进行网络连接.发送什么广播以确定已建立有效的网络连接.我需要验证HTTP的有效网络连接是否存在.我应该注意什么以及我需要做些什么其他测试才能知道存在有效连接.

Answer 1

您可以注册一个BroadcastReceiver建立WiFi连接时通知(或连接更改).

注册BroadcastReceiver:

IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION);
registerReceiver(broadcastReceiver, intentFilter);

然后在你BroadcastReceiver做这样的事情:

@Override
public void onReceive(Context context, Intent intent) {
    final String action = intent.getAction();
    if (action.equals(WifiManager.SUPPLICANT_CONNECTION_CHANGE_ACTION)) {
        if (intent.getBooleanExtra(WifiManager.EXTRA_SUPPLICANT_CONNECTED, false)) {
            //do stuff
        } else {
            // wifi connection was lost
        }
    }
}

欲了解更多信息,请参阅文件BroadcastReceiver和WifiManager

当然,在此之前您应该检查设备是否已连接到WiFi.

编辑:感谢ban-geoengineering,这是检查设备是否已连接的方法:

private boolean isConnectedViaWifi() {
     ConnectivityManager connectivityManager = (ConnectivityManager) appObj.getSystemService(Context.CONNECTIVITY_SERVICE);
     NetworkInfo mWifi = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);     
     return mWifi.isConnected();
}

Answer 2

对我有用的最好的:

AndroidManifest

<receiver android:name="com.AEDesign.communication.WifiReceiver" >
   <intent-filter android:priority="100">
      <action android:name="android.net.wifi.STATE_CHANGE" />
   </intent-filter>
</receiver>

BroadcastReceiver类

public class WifiReceiver extends BroadcastReceiver {

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

      NetworkInfo info = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
      if(info != null && info.isConnected()) {
        // Do your work. 

        // e.g. To check the Network Name or other info:
        WifiManager wifiManager = (WifiManager)context.getSystemService(Context.WIFI_SERVICE);
        WifiInfo wifiInfo = wifiManager.getConnectionInfo();
        String ssid = wifiInfo.getSSID();
      }
   }
}

权限

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

Answer 3

对我来说只有WifiManager.NETWORK_STATE_CHANGED_ACTION作品.

注册广播接收器:

IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
registerReceiver(broadcastReceiver, intentFilter);

并收到:

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

    final String action = intent.getAction();

    if(action.equals(WifiManager.NETWORK_STATE_CHANGED_ACTION)){
        NetworkInfo info = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
        boolean connected = info.isConnected();

        //call your method
    }      
}

Answer 4

用户@JPM和@usman给出的答案非常有用.它工作正常,但在我的情况下,它在我的情况下onReceive多次出现4次,所以我的代码执行多次.

我做了一些修改,按照我的要求制作,现在只有一次

这是广播的java类.

public class WifiReceiver extends BroadcastReceiver {

String TAG = getClass().getSimpleName();
private Context mContext;

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

    mContext = context;


    if (intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) {

        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = cm.getActiveNetworkInfo();

        if (networkInfo != null && networkInfo.getType() == ConnectivityManager.TYPE_WIFI &&
                networkInfo.isConnected()) {
            // Wifi is connected
            WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
            WifiInfo wifiInfo = wifiManager.getConnectionInfo();
            String ssid = wifiInfo.getSSID();

            Log.e(TAG, " -- Wifi connected --- " + " SSID " + ssid );

        }
    }
    else if (intent.getAction().equalsIgnoreCase(WifiManager.WIFI_STATE_CHANGED_ACTION))
    {
        int wifiState = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, WifiManager.WIFI_STATE_UNKNOWN);
        if (wifiState == WifiManager.WIFI_STATE_DISABLED)
        {
            Log.e(TAG, " ----- Wifi  Disconnected ----- ");
        }

    }
}
}

在AndroidManifest中

<receiver android:name=".util.WifiReceiver" android:enabled="true">
        <intent-filter>
            <action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
            <action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
        </intent-filter>
    </receiver>


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

Answer 5

你可以,如果你给用户一个选择,覆盖每一次询问的正常行为启动WiFi连接.

我选择使用三种方法......

public boolean isOnline() 
{
 ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
 NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
 return (networkInfo != null && networkInfo.isConnected());
}  

这是快速检查是否有互联网连接Wifi或CellData.从这里,您可以选择要采取的操作.是否在飞机模式下也需要进行检查.

在一个单独的线程上.我将变量IpAddress设置为=""并进行轮询,直到我有一个有效的IP地址.

  WifiManager wifi;
  wifi = (WifiManager) this.getSystemService(Context.WIFI_SERVICE);
  WifiInfo wifiInfo = wifi.getConnectionInfo();
  int ipAddress = wifiInfo.getIpAddress();
  String ip = null;
  ip = String.format("%d.%d.%d.%d",
  (ipAddress & 0xff),
  (ipAddress >> 8 & 0xff),
  (ipAddress >> 16 & 0xff),
  (ipAddress >> 24 & 0xff));
  Log.e(" >>IP number Begin ",ip);

另一个代码片段...如果它没有打开(用户事先许可)

   if(wifi.isWifiEnabled()!=true)wifi.setWifiEnabled(true);  

Answer 6

为了检测WIFI连接状态,我使用了ConnectivityManager类的CONNECTIVITY_ACTION:

    IntentFilter filter=new IntentFilter();
    filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
    registerReceiver(receiver, filter);

并从您的BroadCastReceiver:

    if (ConnectivityManager.CONNECTIVITY_ACTION.equals(action)) {
        int networkType = intent.getIntExtra(
                android.net.ConnectivityManager.EXTRA_NETWORK_TYPE, -1);
        if (ConnectivityManager.TYPE_WIFI == networkType) {
            NetworkInfo networkInfo = (NetworkInfo) intent
                    .getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
            if (networkInfo != null) {
                if (networkInfo.isConnected()) {

                    // TODO: wifi is connected
                } else {
                    // TODO: wifi is not connected
                }
            }
        }

    }

ps:对我来说很好:)

Answer 7

此代码根本不需要许可.它仅限于Wi-Fi网络连接状态更改(不考虑任何其他网络).接收机静态发布在AndroidManifest.xml文件中,并不需要被导出,因为它会被系统调用protected broadcast,NETWORK_STATE_CHANGED_ACTION在每个网络连接状态的变化.

AndroidManifest:

<receiver
    android:name=".WifiReceiver"
    android:enabled="true"
    android:exported="false">

    <intent-filter>
        <!--protected-broadcast: Special broadcast that only the system can send-->
        <!--Corresponds to: android.net.wifi.WifiManager.NETWORK_STATE_CHANGED_ACTION-->
        <action android:name="android.net.wifi.STATE_CHANGE" />
    </intent-filter>

</receiver>

BroadcastReceiver类:

public class WifiReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
/*
 Tested (I didn't test with the WPS "Wi-Fi Protected Setup" standard):
 In API15 (ICE_CREAM_SANDWICH) this method is called when the new Wi-Fi network state is:
 DISCONNECTED, OBTAINING_IPADDR, CONNECTED or SCANNING

 In API19 (KITKAT) this method is called when the new Wi-Fi network state is:
 DISCONNECTED (twice), OBTAINING_IPADDR, VERIFYING_POOR_LINK, CAPTIVE_PORTAL_CHECK
 or CONNECTED

 (Those states can be obtained as NetworkInfo.DetailedState objects by calling
 the NetworkInfo object method: "networkInfo.getDetailedState()")
*/
    /*
     * NetworkInfo object associated with the Wi-Fi network.
     * It won't be null when "android.net.wifi.STATE_CHANGE" action intent arrives.
     */
    NetworkInfo networkInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);

    if (networkInfo != null && networkInfo.isConnected()) {
        // TODO: Place the work here, like retrieving the access point's SSID

        /*
         * WifiInfo object giving information about the access point we are connected to.
         * It shouldn't be null when the new Wi-Fi network state is CONNECTED, but it got
         * null sometimes when connecting to a "virtualized Wi-Fi router" in API15.
         */
        WifiInfo wifiInfo = intent.getParcelableExtra(WifiManager.EXTRA_WIFI_INFO);
        String ssid = wifiInfo.getSSID();
    }
}
}

权限:

None

Answer 8

2020 年 11 月：

我处理过太多被 Google 弃用的项目。最后，我找到了一个解决方案，使用“registerNetworkCallback”来满足我的特殊要求，正如谷歌目前建议的那样。

我需要的是一种简单的方法来检测我的设备是否在 WIFI 中分配了 IPv4。（我没有尝试过其他情况，我的要求非常具体，但也许这种没有弃用元素的方法将作为其他情况的基础）。

在 API 23、24 和 26（物理设备）以及 API 28 和 29（模拟设备）上进行了测试。

    ConnectivityManager cm 
            = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkRequest.Builder builder = new NetworkRequest.Builder();

    cm.registerNetworkCallback
            (
                    builder.build(),
                    new ConnectivityManager.NetworkCallback()
                    {
                        @Override
                        public void onAvailable(Network network)
                        {
                            //Actions to take with Wifi available.
                        }
                        @Override
                        public void onLost(Network network)
                        {
                            //Actions to take with lost Wifi.
                        }
                    }

            );

（在“MainActivity.Oncreate”内部实现）

注意：在清单中需要“android.permission.ACCESS_NETWORK_STATE”