如何为 WP 应用程序添加多个地理围栏

本文关键字：添加 WP 应用程序 | 更新日期: 2023-09-27 18:36:42

我正在尝试使用地理围栏开发一个基于位置的提醒应用程序。当我只使用一个定位器时，它工作得很好。但是当我添加两个位置时，它仅适用于第一个添加的位置。不显示任何错误或异常。但是第二个位置根本没有出现。我找不到原因。

    BasicGeoposition pos1 = new BasicGeoposition { Latitude = 6.931522, Longitude = 79.842005 };
    BasicGeoposition pos2 = new BasicGeoposition { Latitude = 6.978166, Longitude = 79.927376 };
        Geofence fence1 = new Geofence("loc", new Geocircle(pos1, 100));
        Geofence fence2 = new Geofence("loc", new Geocircle(pos2, 100));
        try
        {
            monitor.Geofences.Add(fence1);
            monitor.Geofences.Add(fence2);
        }

这就是我创建位置并添加到地理围栏的方式。然后用循环调用;

var reports = sender.ReadReports();
        await Dispatcher.RunAsync(CoreDispatcherPriority.High, () =>
        {
            foreach (GeofenceStateChangeReport changeReport in reports)
            {
                if (changeReport.NewState == GeofenceState.Entered)
                {
                    Dispatcher.RunAsync(CoreDispatcherPriority.High, async () =>
                        {
                            MessageDialog dialog = new MessageDialog("u re in the location");
                            await dialog.ShowAsync();
                        });
                }
                if (changeReport.NewState == GeofenceState.Exited)
                {
                    Dispatcher.RunAsync(CoreDispatcherPriority.High, async () =>
                        {
                            MessageDialog dialog = new MessageDialog("u exited from the location");
                            await dialog.ShowAsync();
                        });
                }
            }
        });

如何为 WP 应用程序添加多个地理围栏

您没有添加两个围栏。实际上，您只是在尝试覆盖现有的：

Geofence fence1 = new Geofence("loc", new Geocircle(pos1, 100));
Geofence fence2 = new Geofence("loc", new Geocircle(pos2, 100));

loc它们是您为围栏提供的密钥 - 并且此密钥应该是唯一的（http://msdn.microsoft.com/en-us/library/windows/apps/windows.devices.geolocation.geofencing.geofence.aspx#constructors）。尝试：

Geofence fence1 = new Geofence("loc1", new Geocircle(pos1, 100));
Geofence fence2 = new Geofence("loc2", new Geocircle(pos2, 100));

我建议您将添加新围栏封装到方法中，因为您还应该检查现有围栏：

private void addGeoFence(Geopoint gp, String name, double radius)
{
    // Always remove the old fence if there is any
    var oldFence = GeofenceMonitor.Current.Geofences.Where(gf => gf.Id == name).FirstOrDefault();
    if (oldFence != null)
        GeofenceMonitor.Current.Geofences.Remove(oldFence);
    Geocircle gc = new Geocircle(gp.Position, radius);
    // Listen for all events:
    MonitoredGeofenceStates mask = 0;
    mask |= MonitoredGeofenceStates.Entered;
    mask |= MonitoredGeofenceStates.Exited;
    mask |= MonitoredGeofenceStates.Removed;
    // Construct and add the fence with a dwelltime of 5 seconds.
    Geofence newFence = new Geofence(new string(name.ToCharArray()), gc, mask, false, TimeSpan.FromSeconds(5), DateTimeOffset.Now, new TimeSpan(0));
    GeofenceMonitor.Current.Geofences.Add(newFence);
}
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