问题描述
我有超过200个多边形来创建和我所得到LocationListenerOnChanged的位置（），但我想知道我在基于当前位置的这些多边形。
I have over 200 polygons to create and I get the location by LocationListenerOnChanged() but I would like to know which polygon I am in based on the current location .
我将如何使用经纬度每个多边形每2英里。并且在中签我怎样才能使整个过程更快或将Android操作系统具有内置的功能。
How will I use LatLng to check within within each polygon every 2 miles.And how can I make the entire process faster or will android os has inbuilt function.
我查了很多有关Android地图V2文件，但我没有得到任何信息关于它。我AP preciate w.r.t话题.Thanks任何帮助提前。
I checked a lot of documents related android maps v2 but I did not get any info about it.I appreciate any help w.r.t the topic .Thanks in advance.
推荐答案
有采用的是Android API V2没有直接的方法来知道一个多边形内的经纬度谎言。所以，你需要做的称为里面的多边形点查看一个mathemetical计算。你可以看看前面的帖子建议以下两种方法：
There is no direct method in android api v2 to know if a latlng lies within a polygon. So you need to do a mathemetical calculation known as point inside polygon check. You can check out the below two methods suggested in earlier posts:
1，Raycasting方法
2，Winding数法
如果你的情况，检查点对所有200个或更多的多边形正在放缓您的应用程序，你可以考虑减少检查多边形数量。首先，对于每个多边形，比它们的顶点外，还存放一个近似几何中心。然后当你为检查一个新的位置，发现这个位置与所有多边形的几何中心之间的距离。现在，只需要很少的多边形（比如8），其中心是最接近点，然后做任何上述的点内的多边形检查这些选择的多边形。
If in your case, checking a point against all 200 or more polygons is slowing your app, you can consider reducing the number of polygons to be checked. First of all , for each polygon, other than their vertices, also store an approximate geometric center. Then when you get a new location for checking, find the distance between this location and the geometric center of all the polygons. Now take only few polygons ( say 8) whose centers are closest to the point and then do any of the above point inside polygon check for those chosen polygons.
这篇关于获得位置的地址w.r.t我在多边形的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！