增删实体是CAD二次开发最常见的操作，本文封装了4个最通用的实体增删函数。
添加单个实体
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| public static ObjectId AddEntity(this Database db, Entity entity, string layoutName = null){
if (entity == null) return ObjectId.Null;
ObjectId id = ObjectId.Null;
using (var docLock = DwgOperators.ThisDocument.LockDocument())
{
using (Transaction transaction = db.TransactionManager.StartTransaction())
{
BlockTable bt = transaction.GetObject(db.BlockTableId, OpenMode.ForRead) as BlockTable;
bool flag = true;
ObjectId spaceId = ObjectId.Null;
if (layoutName == null)
spaceId = bt[BlockTableRecord.ModelSpace];
else
{
spaceId = GetLayoutIdByName(db, layoutName);
if (spaceId == ObjectId.Null)
flag = false;
}
if (flag)
{
BlockTableRecord btr = transaction.GetObject(spaceId, OpenMode.ForWrite) as BlockTableRecord;
id = btr.AppendEntity(entity);
transaction.AddNewlyCreatedDBObject(entity, true);
}
transaction.Commit();
}
return id;
}
}
|
添加多个实体
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| public static List<ObjectId> AddEntities<T>(this Database db, List<T> entities, string layoutName = null) where T : Entity
{
List<ObjectId> ids = new List<ObjectId>();
ObjectId id = ObjectId.Null;
using (Transaction transaction = db.TransactionManager.StartTransaction())
{
BlockTable bt = transaction.GetObject(db.BlockTableId, OpenMode.ForRead) as BlockTable;
bool flag = true;
ObjectId spaceId = ObjectId.Null;
if (layoutName == null)
spaceId = bt[BlockTableRecord.ModelSpace];
else
{
spaceId = GetLayoutIdByName(db, layoutName);
if (spaceId == ObjectId.Null)
flag = false;
}
if (flag)
{
BlockTableRecord btr = transaction.GetObject(spaceId, OpenMode.ForWrite) as BlockTableRecord;
foreach (Entity entity in entities)
{
id = btr.AppendEntity(entity);
transaction.AddNewlyCreatedDBObject(entity, true);
ids.Add(id);
}
}
transaction.Commit();
}
return ids;
}
|
删除单个实体
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| public static void DeleteEntity(this Database db, ObjectId id)
{
if (id == ObjectId.Null) return;
using (Transaction transaction = db.TransactionManager.StartTransaction())
{
var entity = transaction.GetObject(id, OpenMode.ForWrite, true);
if (entity != null)
entity.Erase(true);
transaction.Commit();
}
}
|
删除多个实体
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| public static void DeleteEntities(this Database db, params ObjectId[] ids)
{
if (ids == null || ids.Count() == 0) return;
using (Transaction transaction = db.TransactionManager.StartTransaction())
{
foreach (ObjectId id in ids)
{
var entity = transaction.GetObject(id, OpenMode.ForWrite, true);
if (entity != null)
entity.Erase(true);
}
transaction.Commit();
}
}
|