我有一个Windows 10 UWP应用程序，我正在尝试集成Geofencing。我已经阅读了Geofence必须是一个圆圈的文件。这是真的吗？为什么不支持矩形？这看起来很愚蠢，因为在我看来，大多数地理围栏都是矩形的。例如，我的房子，我的院子，建筑物，公园等......比它们更像是矩形（通常）。
这是我尝试过的代码：
private Geofence GenerateGeofence()
{
string fenceKey = new string(Id.Text.ToCharArray());
BasicGeoposition positionNW;
positionNW.Latitude = double.Parse(LatitudeNW.Text);
positionNW.Longitude = double.Parse(LongitudeNW.Text);
positionNW.Altitude = 0.0;
BasicGeoposition positionSE;
positionSE.Latitude = double.Parse(LatitudeSE.Text);
positionSE.Longitude = double.Parse(LongitudeSE.Text);
positionSE.Altitude = 0.0;
// the geofence can be a circular region. However, we are going to use a rectangle
GeoboundingBox geoRect = new GeoboundingBox(positionNW, positionSE);
//Lock into false for single use because we don't want that feature for now.
bool singleUse = false;
// want to listen for enter geofence, exit geofence and remove geofence events
// you can select a subset of these event states
MonitoredGeofenceStates mask = MonitoredGeofenceStates.Entered | MonitoredGeofenceStates.Exited | MonitoredGeofenceStates.Removed;
TimeSpan dwellTime;
TimeSpan duration;
DateTimeOffset startTime;
var maxTimeSpan = TimeSpan.MaxValue;
try
{
//We are going to just hard set the dwell time to 5 seconds for now.
dwellTime = new TimeSpan(ParseTimeSpan("0", defaultDwellTimeSeconds));
// setting up how long you need to be in geofence for enter event to fire
//if (string.Empty != DwellTime.Text)
//{
// dwellTime = new TimeSpan(ParseTimeSpan(DwellTime.Text, defaultDwellTimeSeconds));
//}
//else
//{
// dwellTime = new TimeSpan(ParseTimeSpan("0", defaultDwellTimeSeconds));
//}
// setting up how long the geofence should be active
if (string.Empty != Duration.Text)
{
duration = new TimeSpan(ParseTimeSpan(Duration.Text, 0));
}
else
{
duration = maxTimeSpan;
}
// setting up the start time of the geofence
if (string.Empty != StartTime.Text)
{
startTime = DateTimeOffset.Parse(StartTime.Text);
}
else
{
// if you don't set start time in C# the start time defaults to 1/1/1601
calendar.SetToNow();
startTime = calendar.GetDateTime();
}
}
catch (ArgumentNullException)
{
}
catch (FormatException)
{
_rootPage.NotifyUser("Entered value is not a valid string representation of a date and time", NotifyType.ErrorMessage);
}
catch (ArgumentException)
{
_rootPage.NotifyUser("The offset is greater than 14 hours or less than -14 hours.", NotifyType.ErrorMessage);
}
return new Geofence(fenceKey, geoRect, mask, singleUse, dwellTime, startTime, duration);
}
这大部分来自Windows Universal样本，然后我对其进行了修改。正如您所看到的，API确实有一个GeoboundingBox，它需要一个东北角和一个东南角。似乎有一个矩形被认为。所以，正如你在代码中看到的，我构建了NW lat / long和SE lat / long，我能够成功创建一个GeoboundingBox对象。
然而，在我用这一行返回新的Geofence后，我得到一个例外：
return new Geofence(fenceKey, geoRect, mask, singleUse, dwellTime, startTime, duration);
Geofence对象构造函数只是说它需要传入一个形状，但它显然不喜欢边界框。如果我将代码更改回一个圆圈，如下所示：
private Geofence GenerateGeofence()
{
string fenceKey = new string(Id.Text.ToCharArray());
BasicGeoposition positionNW;
positionNW.Latitude = double.Parse(LatitudeNW.Text);
positionNW.Longitude = double.Parse(LongitudeNW.Text);
positionNW.Altitude = 0.0;
BasicGeoposition positionSE;
positionSE.Latitude = double.Parse(LatitudeSE.Text);
positionSE.Longitude = double.Parse(LongitudeSE.Text);
positionSE.Altitude = 0.0;
// the geofence can be a circular region. However, we are going to use a rectangle
Geocircle geoCircle = new Geocircle(positionNW, 5.0);
//Lock into false for single use because we don't want that feature for now.
bool singleUse = false;
// want to listen for enter geofence, exit geofence and remove geofence events
// you can select a subset of these event states
MonitoredGeofenceStates mask = MonitoredGeofenceStates.Entered | MonitoredGeofenceStates.Exited | MonitoredGeofenceStates.Removed;
TimeSpan dwellTime;
TimeSpan duration;
DateTimeOffset startTime;
var maxTimeSpan = TimeSpan.MaxValue;
try
{
//We are going to just hard set the dwell time to 5 seconds for now.
dwellTime = new TimeSpan(ParseTimeSpan("0", defaultDwellTimeSeconds));
// setting up how long you need to be in geofence for enter event to fire
//if (string.Empty != DwellTime.Text)
//{
// dwellTime = new TimeSpan(ParseTimeSpan(DwellTime.Text, defaultDwellTimeSeconds));
//}
//else
//{
// dwellTime = new TimeSpan(ParseTimeSpan("0", defaultDwellTimeSeconds));
//}
// setting up how long the geofence should be active
if (string.Empty != Duration.Text)
{
duration = new TimeSpan(ParseTimeSpan(Duration.Text, 0));
}
else
{
duration = maxTimeSpan;
}
// setting up the start time of the geofence
if (string.Empty != StartTime.Text)
{
startTime = DateTimeOffset.Parse(StartTime.Text);
}
else
{
// if you don't set start time in C# the start time defaults to 1/1/1601
calendar.SetToNow();
startTime = calendar.GetDateTime();
}
}
catch (ArgumentNullException)
{
}
catch (FormatException)
{
_rootPage.NotifyUser("Entered value is not a valid string representation of a date and time", NotifyType.ErrorMessage);
}
catch (ArgumentException)
{
_rootPage.NotifyUser("The offset is greater than 14 hours or less than -14 hours.", NotifyType.ErrorMessage);
}
return new Geofence(fenceKey, geoCircle, mask, singleUse, dwellTime, startTime, duration);
}
工作正常。
那么，是否有人知道我可以用矩形工作的方法？
谢谢！
答案 0 :(得分：1)
不幸的是，目前支持的唯一形状是地理位置Geocircle。
此属性的类型IGeoshape是一个接口，可以支持地理围栏的多种形状。目前支持的唯一形状是Geocircle，因此这是初始化地理围栏时应该使用的类。
所以尽管有GeoshapeTypes，但地理围栏必须是一个圆圈。