在Xamarin形式的MapBox地图上绘制多边形

Question

我正在使用Mapbox for Xamarin.Forms NuGet在Xamarin表单上实现MapBox。

但是我无法在地图上绘制多边形。

代码：

https://stackoverflow.com/questions/50197347/how-to-reset-only-specific-fields-of-form-in-angular-5

我在这里尝试添加多边形。 坐标是变量，其中包含要处理的所需数据。请帮助我。谢谢。

Answer 1

包括Naxam nuget包，并使用Polyline绘制多边形。最后需要添加一条定制线以完成折线区域。

 Naxam.Controls.Mapbox.Forms.PolylineAnnotation polyline = null;
 ObservableCollection<Naxam.Controls.Mapbox.Forms.Annotation> annotations;


 annotations = new ObservableCollection<Naxam.Controls.Mapbox.Forms.Annotation>();

//Add Polygon
        if (polyline == null)
        {
          polyline = new Naxam.Controls.Mapbox.Forms.PolylineAnnotation
          {
            Id = "my_polyline",
            Title = "Polygon",
            HexColor = "#ff1234",
            Width = 1
          };
        }

        foreach (var cordinate in cordinates)
        {
          if (polyline.Coordinates == null)
          {
            polyline.Coordinates = new ObservableCollection<Naxam.Controls.Mapbox.Forms.Position>
                        { new Naxam.Controls.Mapbox.Forms.Position(cordinate.Latitude, cordinate.Longitude) };
          }
          else
          {
            (polyline.Coordinates as ObservableCollection<Naxam.Controls.Mapbox.Forms.Position>)
                          .Add(new Naxam.Controls.Mapbox.Forms.Position(cordinate.Latitude, cordinate.Longitude));

          }
        }

//We are using polylines so we have to add ending point to line.
        if (polyline.Coordinates != null)
          (polyline.Coordinates as ObservableCollection<Naxam.Controls.Mapbox.Forms.Position>)
                          .Add(new Naxam.Controls.Mapbox.Forms.Position(cordinates[0].Latitude, cordinates[0].Longitude));

       annotations.Add(polyline);

  mapview.Annotations = annotations;