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我已经实现了一个使用c2dm 框架接收推送消息的应用程序。它会在新消息成功到达时显示通知。

但是,如何添加此功能?

当接收者有新消息时,如果它正在运行,请通知我的 Activity。

我尝试使用侦听器模式,即。将活动的引用提供给接收者,但它返回 viewroot callfromwrongthreadexception

这个怎么解决,thx

4

2 回答 2

1

使用监听器。这是接收器的示例,它在接收到新位置时通知 Activity。自定义它:

import android.location.Location;

public interface OnNewLocationListener {
    public abstract void onNewLocationReceived(Location location);
}

接收者:

import java.util.ArrayList;

import org.mabna.order.utils.Farsi;
import org.mabna.order.utils.MessageBox;
import org.mabna.order.utils.Utilities;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.location.GpsStatus;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.Gravity;
import android.widget.Toast;


public class ReceiverPositioningAlarm extends BroadcastReceiver {

    public static final String COMMAND = "SENDER";
    public static final int SENDER_ACT_DOCUMENT = 0;
    public static final int SENDER_SRV_POSITIONING = 1;
    public static final int MIN_TIME_REQUEST = 5 * 1000;
    public static final int MIN_DISTANCE = 10;// in meters

    public static final String ACTION_REFRESH_SCHEDULE_ALARM =
            "org.mabna.order.ACTION_REFRESH_SCHEDULE_ALARM";

    private static Location currentLocation;
    private static Location prevLocation;
    private static Context _context;
    private String provider = LocationManager.GPS_PROVIDER;
    private static Intent _intent;
    private static LocationManager locationManager;
    private static LocationListener locationListener = new LocationListener() {

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {
            try {
                String strStatus = "";
                switch (status) {
                case GpsStatus.GPS_EVENT_FIRST_FIX:
                    strStatus = "GPS_EVENT_FIRST_FIX";
                    break;
                case GpsStatus.GPS_EVENT_SATELLITE_STATUS:
                    strStatus = "GPS_EVENT_SATELLITE_STATUS";
                    break;
                case GpsStatus.GPS_EVENT_STARTED:
                    strStatus = "GPS_EVENT_STARTED";
                    break;
                case GpsStatus.GPS_EVENT_STOPPED:
                    strStatus = "GPS_EVENT_STOPPED";
                    break;

                default:
                    strStatus = String.valueOf(status);
                    break;
                }
                Toast.makeText(_context,
                        "Status: " + strStatus,
                        Toast.LENGTH_SHORT).show();
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        @Override
        public void onProviderEnabled(String provider) {
        }

        @Override
        public void onProviderDisabled(String provider) {
        }

        @Override
        public void onLocationChanged(Location location) {
            try {
                Toast.makeText(_context,
                        "***new location***",
                        Toast.LENGTH_SHORT).show();
                gotLocation(location);
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    };

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

        Toast.makeText(context, "new request received by receiver",
                Toast.LENGTH_SHORT).show();
        _context = context;
        _intent = intent;

        locationManager = (LocationManager) context
                .getSystemService(Context.LOCATION_SERVICE);

        if (locationManager.isProviderEnabled(provider)) {
            locationManager.requestLocationUpdates(provider, MIN_TIME_REQUEST,
                    MIN_DISTANCE, locationListener);

            Location gotLoc = locationManager.getLastKnownLocation(provider);
            gotLocation(gotLoc);
        } else {

            t.setGravity(Gravity.CENTER, 0, 0);
            t.show();


            Intent settinsIntent = new Intent(
                    android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            settinsIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            _context.startActivity(settinsIntent);
        }
    }

    private static void gotLocation(Location location) {
        prevLocation = currentLocation == null ?
                null : new Location(currentLocation);
        currentLocation = location;

        if (isLocationNew()) {
            // saveLocation(location);

            // informing the classes outside of this class that e new point
            // received
            OnNewLocationReceived(location);

            Toast.makeText(_context, "new location saved", Toast.LENGTH_SHORT)
                    .show();
            stopLocationListener();
        }
    }

    private static boolean isLocationNew() {
        if (currentLocation == null) {
            return false;
        } else if (prevLocation == null) {
            return true;
        } else if (currentLocation.getTime() == prevLocation.getTime()) {
            return false;
        } else {
            return true;
        }
    }


    public static void stopLocationListener() {
        locationManager.removeUpdates(locationListener);
        Toast.makeText(_context, "provider stoped", Toast.LENGTH_SHORT)
                .show();
    }

    // listener ----------------------------------------------------

    static ArrayList<OnNewLocationListener> arrOnNewLocationListener =
            new ArrayList<OnNewLocationListener>();

    // Allows the user to set a OnNewLocationListener outside of this class and
    // react to the event.
    // A sample is provided in ActDocument.java in method: startStopTryGetPoint
    public static void setOnNewLocationListener(
            OnNewLocationListener listener) {
        arrOnNewLocationListener.add(listener);
    }

    public static void clearOnNewLocationListener(
            OnNewLocationListener listener) {
        arrOnNewLocationListener.remove(listener);
    }

    // This function is called after the new point received
    private static void OnNewLocationReceived(Location location) {
        // Check if the Listener was set, otherwise we'll get an Exception when
        // we try to call it
        if (arrOnNewLocationListener != null) {
            // Only trigger the event, when we have any listener

            for (int i = arrOnNewLocationListener.size() - 1; i >= 0; i--) {
                arrOnNewLocationListener.get(i).onNewLocationReceived(
                        location);
            }
        }
    }
}

活动中:

Intent intentToFire = new Intent(
                ReceiverPositioningAlarm.ACTION_REFRESH_SCHEDULE_ALARM);
        intentToFire.putExtra(ReceiverPositioningAlarm.COMMAND,
                ReceiverPositioningAlarm.SENDER_ACT_DOCUMENT);

        sendBroadcast(intentToFire);

        OnNewLocationListener onNewLocationListener = new OnNewLocationListener() {
            @Override
            public void onNewLocationReceived(Location location) {
                try {
                    // do everything you want
                    ReceiverPositioningAlarm.clearOnNewLocationListener(this);

                } catch (Exception e) {
                    MessageBox.showException(ActDocument.this, e);
                }
            }
        };

        // start listening for new location
        ReceiverPositioningAlarm.setOnNewLocationListener(
                onNewLocationListener);
于 2011-12-27T08:41:44.687 回答
0

我正在寻找类似的操作:根据 BroadcastReceiver(准确地说是 C2DM 注册)更新活动的 UI TextView。我callFromWrongThreadException试图在自定义线程中更新 ui。

我的解决方案很简单。为清楚起见,我将使用 breceivernail 的答案。我修改了OnNewLocationReceivedActivity 中的方法runOnUiThread()

        @Override
        public void OnNewLocationReceived(Location location) {
            runOnUiThread(new Runnable() {
                public void run(){ 
                     /* update UI here */


                }
            });
        };

如果你得到callFromWrongThreadExceptionbreceivernail 的答案是正确的,你必须弄清楚你在堆栈跟踪的错误位置调用了什么。如果您在更新 UI 时遇到问题,我上面的解决方案可以解决异常。

于 2012-08-20T17:11:32.143 回答