cad中有一条直线,现找到线上的一点,求线上距离该点5m的另外两个点c#
时间: 2024-09-14 18:03:18 浏览: 13
在CAD中,如果需要在一条直线上找到距离特定点一定距离的另外两个点,通常需要使用CAD软件的几何工具或者编程方式进行计算。由于你提到了C#,我将给出一个基于C#代码实现的示例。
首先,你需要有CAD软件(如AutoCAD)的API接口,C#可以通过这些API进行交互。以下是一个简单的C#代码示例,假设你已经有了直线对象(Line)和特定点(Point)的坐标,现在要在直线的两侧找到距离该点5米的位置点:
```csharp
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.EditorInput;
// 这个类是命令行命令的入口点
public class MyCADCommands
{
[CommandMethod("FindPointsOnLine")]
public void FindPointsOnLine()
{
Document acDoc = Application.DocumentManager.MdiActiveDocument;
Database acCurDb = acDoc.Database;
Editor acEd = acDoc.Editor;
// 获取直线对象
PromptEntityOptions peo = new PromptEntityOptions("\n请选择一条直线:");
peo.SetRejectMessage("\n必须选择直线!");
peo.AddAllowedClass(typeof(Autodesk.AutoCAD.DatabaseServices.Line), false);
PromptEntityResult per = acEd.GetEntity(peo);
if (per.Status != PromptStatus.OK)
return;
using (Transaction acTrans = acCurDb.TransactionManager.StartTransaction())
{
// 打开直线对象
Line acLine = acTrans.GetObject(per.ObjectId, OpenMode.ForRead) as Line;
// 获取特定点坐标
PromptPointOptions ppo = new PromptPointOptions("\n请输入特定点的坐标:");
PromptPointResult ppr = acEd.GetPoint(ppo);
if (ppr.Status != PromptStatus.OK)
return;
Point3d pt = ppr.Value;
// 计算直线上的点
Point3dCollection pts = GetPointsOnLine(acLine, pt, 5.0);
// 在CAD中创建点
if (pts != null && pts.Count > 0)
{
BlockTable acBlkTbl;
acBlkTbl = acTrans.GetObject(acCurDb.BlockTableId, OpenMode.ForRead) as BlockTable;
BlockTableRecord acBlkTblRec;
acBlkTblRec = acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace], OpenMode.ForWrite) as BlockTableRecord;
foreach (Point3d p in pts)
{
acBlkTblRec.AppendEntity(new Point(p));
acTrans.AddNewlyCreatedDBObject(new Point(p), true);
}
// 提交事务
acTrans.Commit();
}
}
}
// 这个方法用于计算直线上的点
public Point3dCollection GetPointsOnLine(Line acLine, Point3d pt, double dist)
{
Point3dCollection points = new Point3dCollection();
Vector3d lineDir = acLine.EndPoint - acLine.StartPoint;
Vector3d ptToLineDir = pt - acLine.StartPoint;
double len = ptToLineDir.DotProduct(lineDir) / lineDir.Length;
double distance = Math.Sqrt(ptToLineDir.LengthSquared - len * len);
if (distance > dist)
return null;
// 计算两个新点的坐标
Point3d p1 = pt + new Vector3d(-lineDir.Y, lineDir.X, 0).Normal * dist;
Point3d p2 = pt - new Vector3d(-lineDir.Y, lineDir.X, 0).Normal * dist;
points.Add(p1);
points.Add(p2);
return points;
}
}
```
上述代码中,`GetPointsOnLine`方法根据输入的直线对象、特定点坐标和距离,计算出在直线上距离特定点5米的两个点的坐标,并将这些点添加到CAD的模型空间中。请注意,这段代码仅作为示例,实际应用中可能需要根据具体的CAD软件和API进行调整。