C#基于Autocad的二次开发(5.图形镜像)

开始之前确保已完成步骤1创建解决方案和类库项目，并在对应项目中安装nuget包

部分场景需要将图形中的内容根据x轴或y轴，甚至自定义的对称轴进行镜像，这时需要依照目标图形以及对称轴生成镜像图形。

ACD.CadCore项目中创建Extensions.Autodesk.cs类文件，封装镜像扩展方法

public static partial class Extensions
   {
	/// <summary>
	/// 镜像图形
	/// </summary>
	/// <param name="ent">图形对象的ObjectId</param>
	/// <param name="point1">第一个镜像点</param>
	/// <param name="point2">第二个镜像点</param>
	/// <param name="isEraseSource">是否删除原图形</param>
	/// <returns>返回新的图形对象  没有加入图形数据库的情况</returns>
	public static Entity MirrorEntity(this Entity ent, Point3d point1, Point3d point2, bool isEraseSource)
	{

		// 声明一个图形对象用于返回
		Entity entR;

		if (ent.IsNewObject == true)
		{
			// 计算镜像的变换矩阵
			Matrix3d mt = Matrix3d.Mirroring(new Line3d(point1, point2));
			entR = ent.GetTransformedCopy(mt);
		}
		else
		{
			entR = ent.ObjectId.MirrorEntity(point1, point2, isEraseSource);
		}
		return entR;
	}

	public static Entity MirrorEntity(this ObjectId entId, Point3d point1, Point3d point2, bool isEraseSource)
	{
		// 声明一个图形对象用于返回
		Entity entR;
		// 计算镜像的变换矩阵
		Matrix3d mt = Matrix3d.Mirroring(new Line3d(point1, point2));
		// 打开事务处理
		using (Transaction trans = entId.Database.TransactionManager.StartTransaction())
		{
			// 判断是否删除原对象
			if (isEraseSource)
			{
				// 打开原对象
				Entity ent = (Entity)trans.GetObject(entId, OpenMode.ForWrite);
				// 执行变换
				ent.TransformBy(mt);
				entR = ent;
			}
			else
			{

				// 打开原对象
				Entity ent = (Entity)trans.GetObject(entId, OpenMode.ForRead);
				entR = ent.GetTransformedCopy(mt);
			}
			return entR;
		}
	}
}

CSHARP

接着在ACD.CadCore项目中创建ACDOperation.Reverse.cs类文件，实现镜像操作

public partial class ACDOperation
   {
       public bool Reverse(string originalFullPath, string reverseFullPath, Point3d point1, Point3d point2)
       {
           if (!File.Exists(originalFullPath)) return false;

           if (File.Exists(reverseFullPath)) return true;

           try
           {
               string directoryPath = Path.GetDirectoryName(reverseFullPath);
               if (!Directory.Exists(directoryPath)) Directory.CreateDirectory(directoryPath);

               File.Copy(originalFullPath, reverseFullPath);
           }
           catch (IOException)
           {
               return false;
           }

           using (Database wblockDb = new Database(false, true))
           {
               try
               {
                   wblockDb.ReadDwgFile(reverseFullPath, FileOpenMode.OpenForReadAndWriteNoShare, true, null);
                   wblockDb.CloseInput(true);

                   using (Transaction tr = wblockDb.TransactionManager.StartTransaction())
                   {
                       BlockTable currblockTable = tr.GetObject(wblockDb.BlockTableId, OpenMode.ForRead) as BlockTable;

                       BlockTableRecord currblockTableRecord = tr.GetObject(currblockTable[BlockTableRecord.ModelSpace], OpenMode.ForWrite) as BlockTableRecord;

                       foreach (var item in currblockTableRecord)
                       {
                           Entity entity = tr.GetObject(item, OpenMode.ForWrite) as Entity;

                           if (entity is Dimension)
                           {
                               var dimension = entity as Dimension;
                               var normal = dimension.Normal;
                               dimension.MirrorEntity(point1, point2, true);
                               dimension.Normal = normal;
                           }
                           else
                           {
                               entity.MirrorEntity(point1, point2, true);
                           }
                       }
                       tr.Commit();
                   }
                   wblockDb.SaveAs(reverseFullPath, DwgVersion.Current);
               }
               catch (Exception)
               {
                   return false;
               }
           }
           return true;
       }
   }

CSHARP

通过originalFullPath文件路径，读取目标图形，将目标图形中的所有对象依次执行镜像操作，最后提交事物，保存新的图形文件到reverseFullPath。
镜像后，其中Dimension标注对象会存在标注内容颠倒的问题，需要特殊处理