计算逆时针夹角（有向角度）——CAD c# 实现两条线（向量）的逆时针夹角

效果如下：

附部分代码如下：

        public void 逆时针夹角Demo(){// 获取当前 CAD 文档和编辑器Document doc = Application.DocumentManager.MdiActiveDocument;Editor ed = doc.Editor;Database db = doc.Database;try{Point3d vec1Start, vec1End;if (!GetTwoPoints(ed, "请选择第一个向量的起点", "请选择第一个向量的终点", out vec1Start, out vec1End)){ed.WriteMessage("\n操作已取消。");return;}db.AddLineToModeSpace(vec1Start, vec1End);Point3d vec2Start, vec2End;if (!GetTwoPoints(ed, "请选择第二个向量的起点", "请选择第二个向量的终点", out vec2Start, out vec2End)){ed.WriteMessage("\n操作已取消。");return;}db.AddLineToModeSpace(vec2Start, vec2End); // 添加第二个向量到模型空间Vector3d vec1 = vec1End - vec1Start; // 向量1 = 终点1 - 起点1Vector3d vec2 = vec2End - vec2Start; // 向量2 = 终点2 - 起点2double ccwAngle = vec1.逆时针角度(vec2); // 调用扩展方法double angleDeg = ccwAngle * (180.0 / Math.PI); // 弧度转角度var str = $"\n两个向量的逆时针夹角为：{angleDeg:F5}°";ed.WriteMessage(str);MessageBox.Show(str); // 显示结果}catch (Exception ex){ed.WriteMessage($"\n错误：{ex.Message}");}}/// <summary>/// 辅助方法：提示用户选择两个点/// </summary>/// <returns>是否成功选择两个点</returns>private bool GetTwoPoints(Editor ed, string firstPrompt, string secondPrompt, out Point3d p1, out Point3d p2){p1 = Point3d.Origin;p2 = Point3d.Origin;// 选择第一个点PromptPointOptions opt1 = new PromptPointOptions("\n" + firstPrompt);PromptPointResult res1 = ed.GetPoint(opt1);if (res1.Status != PromptStatus.OK) return false;p1 = res1.Value;// 选择第二个点PromptPointOptions opt2 = new PromptPointOptions("\n" + secondPrompt){UseBasePoint = true, // 允许使用基点（如相对坐标）BasePoint = p1 // 基点设为第一个点，方便用户输入相对坐标};PromptPointResult res2 = ed.GetPoint(opt2);if (res2.Status != PromptStatus.OK) return false;p2 = res2.Value;return true;}