public static void DrawLine()
{
Editor ed = Application.DocumentManager.MdiActiveDocument.Editor;
Database db = HostApplicationServices.WorkingDatabase;
Stopwatch watch = new Stopwatch();
watch.Start();
for (int i = -5000; i < 5000; i += 1000)
{
Point3d startPoint = new Point3d(i, Math.Sqrt((Math.Pow(5000, 2) - Math.Pow(Math.Abs(i), 2))), 0);
Point3d endPoint = new Point3d(-startPoint.X, -startPoint.Y, 0);
Line line = new Line(startPoint, endPoint);
//获得在此多段线上离起点距离为中点的点
Point3d pts = line.GetPointAtDist(line.Length / 2);
//得到这个点的切线方向
Vector3d acVQ = line.GetFirstDerivative(pts);
//旋转90度得到法线方向(顺)
Vector3d acVF = acVQ.RotateBy(Math.PI / 2, Vector3d.ZAxis);
//得到此向量上距离此点距离dust的点PT1
Point3d txtPosition;
double txtRotation;
DBText text = new DBText();
//得到此向量上距离此点距离dust的点PT1
txtPosition = pts.Add(acVF.GetNormal() * 100);
txtRotation = acVF.GetAngleTo(Vector3d.YAxis);
text.Position = txtPosition;
text.Height = 150;
text.TextString = "测试文字";
//text.Justify=AttachmentPoint.BottomLeft;
text.Rotation = txtRotation;
text.WidthFactor = 0.7;
//text.HorizontalMode = TextHorizontalMode.TextLeft;
line.ColorIndex = 1;
db.AddToModelSapce(line);
db.AddToModelSapce(text);
}
watch.Stop();
ed.WriteMessage("\n命令执行完成：{0} ms", watch.ElapsedMilliseconds.ToString());
watch.Reset();
}