如何绘制圆在C＃中使用GMAP.NET的地图 [英] How to draw circle on the MAP using GMAP.NET in C#

问题描述

我在C＃中使用GMAP.NET。我能够在表单上显示的地图，我现在想通过点击certian点，保持鼠标左键并拖动鼠标高达特定的地方画了一个圈鼠标。一旦圆圈绘制我想要得到它从圆心方圆十里我确信GMAP是能够做到的。我使用Opentstreet地图。

I am using GMAP.NET in c#. I am able to display the map on the form, now i am trying to draw a CIRCLE mouse by clicking on a certian point, keeping the left mouse button and dragging the mouse upto specific place. Once the circle is drawn I want to get its radius in miles from the center point which I am sure GMAP is capable of doing it. I am using Opentstreet maps.

我只是无法functionly achive这一点，谁曾与GMAP控制起到好心分享一些代码，将工作经验的人。

I am just unable to achive this functionly, anybody who has played with GMAP control kindly share your experience with some code which will work.

感谢

推荐答案

这是我知道的唯一途径能取得这样的成绩是创建PointLatLng点列表，并绘制这些多边形。下面是一个例子。

the only way that I am aware of that can achieve such a result is to create a list with PointLatLng points and draw them as a polygon. Here is an example.

private void CreateCircle(PointF point, double radius, int segments)
{

List<PointLatLng> gpollist = new List<PointLatLng>();

double seg = Math.PI * 2 / segments;

int y = 0;
for (int i = 0; i < segments; i++)
{
    double theta = seg * i;
    double a = point.x + Math.cos( theta ) * radius;
    double b = point.y + Math.sin( theta ) * radius;

    PointLatLng gpoi = new PointLatLng(a,b);

    gpollist.Add(gpoi);
 }
 GMapPolygon gpol = new GMapPolygon(gpollist, "pol");

 overlayOne.Polygons.Add(gpol);
 }

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