我想使用 aService来使用 AsyncTask 建立我的连接。我想在每个活动中引用在m_netLinkIp连接设置期间创建的变量。
目前我的服务看起来像这样:
package de.bertrandt.bertrandtknx;
import de.bertrandt.bertrandtknx.Controls.Dimmer;
import tuwien.auto.calimero.link.KNXNetworkLinkIP;
import tuwien.auto.calimero.process.ProcessCommunicator;
import android.app.ProgressDialog;
import android.app.Service;
import android.content.Intent;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.AsyncTask;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
import android.widget.Toast;
public class ConnectionService extends Service {
    private static final String TAG = "ConnectionService";
    private static KNXNetworkLinkIP m_netLinkIp = null;
    private static ProcessCommunicator m_pc = null;
    private static boolean connection_ok;
           @Override
           public IBinder onBind(Intent intent) {
              return null;
           }
           @Override
           public void onCreate() {
              //code to execute when the service is first created
               new Connect().execute();
           }
           @Override
           public void onDestroy() {
              //code to execute when the service is shutting down
               new Disconnect().execute();
           }
           @Override
           public void onStart(Intent intent, int startid) {
              //code to execute when the service is starting up
           }
    /**
     * Connect Async
     * */
    private class Connect extends AsyncTask<String, Void, String> {
          ProgressDialog dialog;
          boolean ok;
          @Override
          protected String doInBackground(String... params) {
              try {
                  //get local IP address
                  String ipAddress = getIpAddr();
                  System.out.println("WiFi address is " + ipAddress);
                  m_netLinkIp = Calimero.Util.connect(ipAddress, "192.168.0.2");
                  if (m_netLinkIp == null){
                      System.out.println("Can not connect to Demobard");
                      ok = false;
                  }
                  else{
                      System.out.println("Connected to Demoboard");
                      ok = true;
                      }
               } catch (Exception e) {         
                   e.printStackTrace(); 
               }
               return null;
          }      
          @Override
          protected void onPostExecute(String result) { 
            //dialog.dismiss();
            Toast.makeText(getApplicationContext(),
                    "Verbindung mit Demoboard " +
                            ((ok == true) ? "hergestellt" : "fehlgeschlagen"), Toast.LENGTH_LONG).show();
            if(ok == false){
                //show reconnect dialog
                //reconnect_dialog();
            }
          }
          @Override
          protected void onPreExecute() {
           // Setup Progress Dialog
           dialog = new ProgressDialog(Dimmer.this);
           dialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
           dialog.setMessage("Bitte warten, verbinde mit KNX-Board");
           dialog.setIndeterminate(true);
           dialog.show();
          }
    }
    /**
     * GetIPAddress Async
     * */
    public String getIpAddr() {
           WifiManager wifiManager = (WifiManager) getSystemService(WIFI_SERVICE);
           WifiInfo wifiInfo = wifiManager.getConnectionInfo();
           int ip = wifiInfo.getIpAddress();
           String ipString = String.format(
           "%d.%d.%d.%d",
           (ip & 0xff),
           (ip >> 8 & 0xff),
           (ip >> 16 & 0xff),
           (ip >> 24 & 0xff));
           return ipString.toString();
    }
    /**
     * Disconnect Async
     * */
    private class Disconnect extends AsyncTask<String, Void, String> {
          @Override
          protected String doInBackground(String... params) {
                    try {
                        Calimero.Util.disconnect(m_netLinkIp);
                    } catch (Exception e) {
                        e.printStackTrace(); 
                    }
                return null;
          }      
    }
}
所以这是我的问题:
1.)如何在我的任何活动中调用服务并获取对m_netLinkIp变量的引用,这样我就不必在每个活动中重新连接?目前我这样称呼它:startService(new Intent(this, ConnectionService.class));
解决方案:我将 Service 类中的全局变量更改为public static KNXNetworkLinkIP m_netLinkIp = null;,现在我可以在每个活动中调用它,如下所示:m_netLinkIp= ConnectionService.m_netLinkIp;
2.) 如何在每个活动中显示 ProgressBar?我必须在声明中添加活动:dialog = new ProgressDialog(Dimmer.this);
谢谢!