问题
I am trying to find a way to create several polygon geofences with iOS. I need to draw multiple zones in a city to represent areas, streets, etc. From what I've read so far, iOS only allows circular zone from a geolocated device.
- Is it feasible with iOS?
- Is there a web app somewhere to draw polygons on a map and generate the coordinates in an array?
回答1:
1) iOS only allows to create circular geofences indeed however what you are trying to achieve is possible with some extra logic. I have developed similar features so I suggest you to do the following:
- create a circular geofence that embeds your polygon
- when the device gets notified as being within the circular geofence, start the GPS
- every time you get a location update, check if its coordinates are within the polygon
- turn off the GPS as soon as the device's location is found within the polygon, unless you need to be notified when exiting the polygon as well
- turn off the GPS when the device gets notified as outside the circular geofence
As you need polygon geofences I guess you expect a good level of accuracy, so you would need to use an extra layer of GPS on top of the geofencing anyways, as geofencing is not accurate at all.
2) Have a look at those links:
- https://github.com/thedilab/v3-polygon-shape-creator
- https://github.com/tparkin/Google-Maps-Point-in-Polygon
来源：https://stackoverflow.com/questions/23789341/polygon-geofencing-with-ios