我使用服务连接到使用AsyncTask的网络.我想显示ProgressDialog,直到应用程序连接到网络.但是我怎么能这样做呢?
我的服务看起来像这样:
package de.bertrandt.bertrandtknx;
import tuwien.auto.calimero.link.knxNetworkLinkIP;
import tuwien.auto.calimero.process.ProcessCommunicator;
import de.bertrandt.bertrandtknx.Controls.OnOff;
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.widget.Toast;
public class ConnectionService extends Service {
public static knxNetworkLinkIP m_netLinkIp = null;
private static ProcessCommunicator m_pc = null;
@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();
}
public void onStartCommand(Intent intent, int startid) {
//code to execute when the service is starting up
}
/**
* 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();
}
/**
* 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(OnOff.this);
dialog.setProgressstyle(ProgressDialog.STYLE_SPINNER);
dialog.setMessage("Bitte warten, verbinde mit knx-Board");
dialog.setIndeterminate(true);
dialog.show();*/
}
}
/**
* 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;
}
}
}
对话框应显示在启动服务的活动中,直到连接应用程序.
解决方法:
因此,服务不是您必须使用观察者模式的UI.您的活动必须在服务中注册一个侦听器,以便服务可以通知活动特殊事件(如开始加载或完成加载).
您必须在服务类中添加以下intercae:
public interface serviceObserver {
public void startLoading();
public void stopLoading();
}
您的活动必须实现serviceObserver.您的服务必须存储在活动中创建的serviceObserver中的实例.
如果您的服务在没有活动的情况下运行,我建议使用广播接收器进行通信.