Question

在我的应用程序上我有这个方法，它告诉我是否有互联网连接，但我想知道是否有办法检查它是否是一个良好的网络连接。

public static boolean existInternetConnection() {
    boolean booThereConnection = false;
    if (context == null)
        context = activity.getApplicationContext();
    ConnectivityManager cm = (ConnectivityManager) context.getSystemService(context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = cm.getActiveNetworkInfo();
    if (netInfo != null && netInfo.isConnectedOrConnecting())
        booThereConnection = true;

    return booThereConnection;
}

Answer 1

试试这个。但请记住，android总是说WiFi网络总是比移动网络更强大。所以我的代码用于检查移动数据的强度。

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.telephony.TelephonyManager;

public class Connectivity {
    /*
     * HACKISH: These constants aren't yet available in my API level (7), but I need to handle these cases if they come up, on newer versions
     */
    public static final int NETWORK_TYPE_EHRPD=14; // Level 11
    public static final int NETWORK_TYPE_EVDO_B=12; // Level 9
    public static final int NETWORK_TYPE_HSPAP=15; // Level 13
    public static final int NETWORK_TYPE_IDEN=11; // Level 8
    public static final int NETWORK_TYPE_LTE=13; // Level 11

    /**
     * Check if there is any connectivity
     * @param context
     * @return
     */
    public static boolean isConnected(Context context){
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo info = cm.getActiveNetworkInfo();
        return (info != null && info.isConnected());
    }
    /**
     * Check if there is fast connectivity
     * @param context
     * @return
     */
    public static boolean isConnectedFast(Context context){
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo info = cm.getActiveNetworkInfo();
        return (info != null && info.isConnected() && Connectivity.isConnectionFast(info.getType(),info.getSubtype()));
    }

    /**
     * Check if the connection is fast
     * @param type
     * @param subType
     * @return
     */
    public static boolean isConnectionFast(int type, int subType){
        if(type==ConnectivityManager.TYPE_WIFI){
            System.out.println("CONNECTED VIA WIFI");
            return true;
        }else if(type==ConnectivityManager.TYPE_MOBILE){
            switch(subType){
            case TelephonyManager.NETWORK_TYPE_1xRTT:
                return false; // ~ 50-100 kbps
            case TelephonyManager.NETWORK_TYPE_CDMA:
                return false; // ~ 14-64 kbps
            case TelephonyManager.NETWORK_TYPE_EDGE:
                return false; // ~ 50-100 kbps
            case TelephonyManager.NETWORK_TYPE_EVDO_0:
                return true; // ~ 400-1000 kbps
            case TelephonyManager.NETWORK_TYPE_EVDO_A:
                return true; // ~ 600-1400 kbps
            case TelephonyManager.NETWORK_TYPE_GPRS:
                return false; // ~ 100 kbps
            case TelephonyManager.NETWORK_TYPE_HSDPA:
                return true; // ~ 2-14 Mbps
            case TelephonyManager.NETWORK_TYPE_HSPA:
                return true; // ~ 700-1700 kbps
            case TelephonyManager.NETWORK_TYPE_HSUPA:
                return true; // ~ 1-23 Mbps
            case TelephonyManager.NETWORK_TYPE_UMTS:
                return true; // ~ 400-7000 kbps
            // NOT AVAILABLE YET IN API LEVEL 7
            case Connectivity.NETWORK_TYPE_EHRPD:
                return true; // ~ 1-2 Mbps
            case Connectivity.NETWORK_TYPE_EVDO_B:
                return true; // ~ 5 Mbps
            case Connectivity.NETWORK_TYPE_HSPAP:
                return true; // ~ 10-20 Mbps
            case Connectivity.NETWORK_TYPE_IDEN:
                return false; // ~25 kbps 
            case Connectivity.NETWORK_TYPE_LTE:
                return true; // ~ 10+ Mbps
            // Unknown
            case TelephonyManager.NETWORK_TYPE_UNKNOWN:
                return false; 
            default:
                return false;
            }
        }else{
            return false;
        }
    }

 }

Answer 2

试试这个

String[] items = {"alphabet", "a", "b", "c", "d", "a"};
int counter = 1;
for(String item : items) {
   Object itemId = tree.addItem(counter);
   tree.setItemCaption(counter, item);
   if(counter >1) {
     tree.setParent(counter, 1);
   }
   counter++;
}

Answer 3

您可以为此使用简单的功能：

  public boolean isConnectToInternet() {
    ConnectivityManager connectivity = (ConnectivityManager) getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
    if (connectivity != null) {
      NetworkInfo[] info = connectivity.getAllNetworkInfo();
      if (info != null)
        for (int i = 0; i < info.length; i++)
          if (info[i].getState() == NetworkInfo.State.CONNECTED) {
            return true;
          }
    }
    return false;
  }

Android检查互联网连接

3 个答案: