android - WI-FI 开启但未连接网络

Question

我正在开发一个需要检查互联网连接的 Android 应用程序。当设备的 WI-FI 关闭时它工作得很好但是当我打开 Wi-Fi 但没有连接到可用网络时，它是强制关闭。可能是什么问题？请帮助 bool isNetworkConnectionAvailable() {

  boolean connected = false;

    ConnectivityManager cm =(ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

    if (cm != null) {
        NetworkInfo ni = cm.getActiveNetworkInfo();

        if(ni != null){

                if(ni.isConnected())
                connected = true;
                else
                    connected=false;

           }

    }



    return connected;

}

Answer 1

你的问题是当你的设备连接到 WIFI 但 WIFI 没有连接到互联网时你返回 true。你可以通过编程方式执行 ping 命令来解决这个问题。

想法:

1) 检查您是否已连接到 WIFI。

2) 如果您连接到 wifi ping 以检查网络可用性。

代码:

public static boolean isOnline(Context con,String url){

    ConnectivityManager cm = (ConnectivityManager)con.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = cm.getActiveNetworkInfo();
    if (netInfo != null && netInfo.isConnectedOrConnecting()) { 
        if(u!=null){
            return ping(url);
        }else{
            return true;
        }
    }else{
        return false;
    }
}

Ping方法:

public static boolean ping(String u) { 
        try {
            URL url = new URL(u);
            HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
            urlc.setConnectTimeout(500); // Time is in Milliseconds to wait for ping response
            urlc.connect();
            if (urlc.getResponseCode() == 200) {
                Log.i(TAG, "* ping  with ResponseCode: "+urlc.getResponseCode());
                return true;
            }else{
                Log.i(TAG, "* Connection is too slow with ResponseCode: "+urlc.getResponseCode());
                return false;
            }
        }catch (MalformedURLException e1){
            Log.e(TAG,"Erroe in URL to ping"+e1);
            return false;
        }catch (IOException e){
            Log.e(TAG,"Error in ping"+e);
            return false;
        }
    }