android - 单击按钮不会启动 Android App Widget 中的服务

Question

我在启动服务来更新我作为练习创建的 AppWidget 时遇到了问题。我正在尝试从 DDMS 获取欺骗位置数据的纬度和经度以显示在小部件中。该小部件使用服务来更新 TextView，这可能有点矫枉过正，但我​​想遵循在 AppWidgets 中似乎很常见的模板，它可以完成更多工作(例如 Forecast 小部件或 Wiktionary 小部件)。

现在，我没有收到任何错误消息或奇怪的行为；按下按钮时什么也没有发生。我对可能出了什么问题感到有点困惑。那里的任何人都可以指出我正确的方向吗？

此外，如果我的位置逻辑有误，我也很乐意就此提出建议。我查看了几篇博客、Google 示例和文档，但我对它的工作原理有点模糊。

这是小部件的当前状态:

public class Widget extends AppWidgetProvider
{
    static final String TAG = "Widget"; 
    /**
     * {@inheritDoc}
     */
    public void onUpdate(Context context, AppWidgetManager appWidgetManager,
                        int[] appWidgetIds)
    {
        // Create an intent to launch the service
        Intent serviceIntent = new Intent(context, UpdateService.class);

        // PendingIntent is required for the onClickPendingIntent that actually
        // starts the service from a button click
        PendingIntent pendingServiceIntent = 
            PendingIntent.getService(context, 0, serviceIntent, 0);

        // Get the layout for the App Widget and attach a click listener to the
        // button
        RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.main);
        views.setOnClickPendingIntent(R.id.address_button, pendingServiceIntent);
        super.onUpdate(context, appWidgetManager, appWidgetIds);
    }

    // To prevent any ANR timeouts, we perform the update in a service;
    // really should have its own thread too
    public static class UpdateService extends Service
    {
        static final String TAG = "UpdateService"; 
        private LocationManager locationManager;
        private Location currentLocation;
        private double latitude;
        private double longitude;

        public void onStart(Intent intent, int startId)
        {
            // Get a LocationManager from the system services
            locationManager = 
                (LocationManager) getSystemService(Context.LOCATION_SERVICE);

            // Register for updates from spoofed GPS
            locationManager.requestLocationUpdates("gps", 30000L, 0.0f, new LocationListener()
            {
                @Override
                public void onLocationChanged(Location location)
                {
                    currentLocation = location;
                }

                @Override
                public void onProviderDisabled(String provider) {}

                @Override
                public void onProviderEnabled(String provider) {}

                @Override
                public void onStatusChanged(String provider, int status,
                        Bundle extras) {}       
            });
            // Get the last known location from GPS
            currentLocation = 
                locationManager.getLastKnownLocation("gps");

            // Build the widget update
            RemoteViews updateViews = buildUpdate(this);

            // Push update for this widget to the home screen
            ComponentName thisWidget = new ComponentName(this, Widget.class);

            // AppWidgetManager updates AppWidget state; gets information about 
            // installed AppWidget providers and other AppWidget related state 
            AppWidgetManager manager = AppWidgetManager.getInstance(this);

            // Updates the views based on the RemoteView returned from the
            // buildUpdate method (stored in updateViews)
            manager.updateAppWidget(thisWidget, updateViews);
        }

        public RemoteViews buildUpdate(Context context)
        {
            latitude = currentLocation.getLatitude();
            longitude = currentLocation.getLongitude();
            RemoteViews updateViews = 
                new RemoteViews(context.getPackageName(), R.layout.main);
            updateViews.setTextViewText(R.id.latitude_text, "" + latitude);
            updateViews.setTextViewText(R.id.longitude_text, "" + longitude);
            return updateViews;
        }

        @Override
        public IBinder onBind(Intent intent) {
            // We don't need to bind to this service
            return null;
        }
    }

}

Answer 1

尝试设置最后一个参数

  PendingIntent.getService(context, 0, serviceIntent, 0);

到:

  PendingIntent.getService(context, 0, serviceIntent, Intent.FLAG_ACTIVITY_NEW_TASK);

此外，有时您需要将 addData 添加到您的 Intent 中，以便 Android 将其区分为新事物，这有点 hacky 但似乎有效，因此添加:

  serviceIntent.setData(Uri.parse("uri::somethingrandomandunique");