public override void draw(Graphics graphics, GISView view)
{
Point screenpoint = view.ToScreenPoint(centroid);
graphics.FillEllipse(new SolidBrush(Color.Red),
new Rectangle(screenpoint.X - 3, screenpoint.Y - 3, 6, 6));
}
public static Point[] GetScreenPoints(List <GISVertex> _vertexes, GISView view)
{
Point[] points = new Point[_vertexes.Count];
for (int i = 0; i < points.Length; i++)
{
points[i] = view.ToScreenPoint(_vertexes[i]);
}
return(points);
}
public void draw(Graphics graphics, GISView view, GISVertex location, int index)
{
Point screenpoint = view.ToScreenPoint(location);//转换坐标到屏幕点
graphics.DrawString(values[index].ToString(),
new Font("宋体", 20),
new SolidBrush(Color.Green),
new PointF(screenpoint.X, screenpoint.Y));
}
//根据鼠标点和距离阈值构造点选范围extent
public GISExtent BuildExtent(GISVertex vertex, GISView view)
{
Point p0 = view.ToScreenPoint(vertex);
Point p1 = new Point(p0.X + (int)GISConst.MinScreenDistance, p0.Y + (int)GISConst.MinScreenDistance);
Point p2 = new Point(p0.X - (int)GISConst.MinScreenDistance, p0.Y - (int)GISConst.MinScreenDistance);
GISVertex gmp1 = view.ToMapVertex(p1);
GISVertex gmp2 = view.ToMapVertex(p2);
return(new GISExtent(gmp1.x, gmp2.x, gmp1.y, gmp2.y));
}