我有一个项目，将元素添加到AutoCad绘图中。我注意到我开始用多种方法编写相同的十行代码（为简单起见仅显示两行）。
初步实施：
您会注意到，唯一真正改变的是添加一条线而不是一个圆。
[CommandMethod("Test", CommandFlags.Session)]
public void Test()
{
AddLineToDrawing();
AddCircleToDrawing();
}
private void AddLineToDrawing()
{
using (DocumentLock lockedDocument = Application.DocumentManager.MdiActiveDocument.LockDocument())
{
using (Database database = Application.DocumentManager.MdiActiveDocument.Database)
{
using (Transaction transaction = database.TransactionManager.StartTransaction())//Start the transaction
{
//Open the block table for read
BlockTable blockTable = transaction.GetObject(database.BlockTableId, OpenMode.ForRead) as BlockTable;
//Open the block table record model space for write
BlockTableRecord blockTableRecord = (BlockTableRecord)transaction.GetObject(blockTable[BlockTableRecord.ModelSpace], OpenMode.ForWrite);
Line line = new Line(new Point3d(0, 0, 0), new Point3d(10, 10, 0));
blockTableRecord.AppendEntity(line);
transaction.AddNewlyCreatedDBObject(line, true);
transaction.Commit();
}
}
}
}
private void AddCircleToDrawing()
{
using (DocumentLock lockedDocument = Application.DocumentManager.MdiActiveDocument.LockDocument())
{
using (Database database = Application.DocumentManager.MdiActiveDocument.Database)
{
using (Transaction transaction = database.TransactionManager.StartTransaction())//Start the transaction
{
//Open the block table for read
BlockTable blockTable = transaction.GetObject(database.BlockTableId, OpenMode.ForRead) as BlockTable;
//Open the block table record model space for write
BlockTableRecord blockTableRecord = (BlockTableRecord)transaction.GetObject(blockTable[BlockTableRecord.ModelSpace], OpenMode.ForWrite);
Circle circle = new Circle(new Point3d(0, 0, 0), new Vector3d(0, 0, 0), 10);
blockTableRecord.AppendEntity(circle);
transaction.AddNewlyCreatedDBObject(circle, true);
transaction.Commit();
}
}
}
}
注入：这种方法消除了重复的代码，但是我认为可读性很差。
[CommandMethod("Test", CommandFlags.Session)]
public void Test()
{
PerformActionOnBlockTable(new CircleDrawer());
PerformActionOnBlockTable(new LineDrawer());
}
public interface IDraw
{
DBObject DrawObject(BlockTableRecord blockTableRecord);
}
public class CircleDrawer : IDraw
{
public DBObject DrawObject(BlockTableRecord blockTableRecord)
{
Circle circle = new Circle(new Point3d(0, 0, 0), new Vector3d(0, 0, 0), 10);
blockTableRecord.AppendEntity(circle);
return circle;
}
}
public class LineDrawer : IDraw
{
public DBObject DrawObject(BlockTableRecord blockTableRecord)
{
Line line = new Line(new Point3d(0, 0, 0), new Point3d(10, 10, 0));
blockTableRecord.AppendEntity(line);
return line;
}
}
private void PerformActionOnBlockTable(IDraw drawer)
{
using (DocumentLock lockedDocument = Application.DocumentManager.MdiActiveDocument.LockDocument())
{
using (Database database = Application.DocumentManager.MdiActiveDocument.Database)
{
using (Transaction transaction = database.TransactionManager.StartTransaction())//Start the transaction
{
//Open the block table for read
BlockTable blockTable = transaction.GetObject(database.BlockTableId, OpenMode.ForRead) as BlockTable;
//Open the block table record model space for write
BlockTableRecord blockTableRecord = (BlockTableRecord)transaction.GetObject(blockTable[BlockTableRecord.ModelSpace], OpenMode.ForWrite);
DBObject newObject = drawer.DrawObject(blockTableRecord);
transaction.AddNewlyCreatedDBObject(newObject, true);
transaction.Commit();
}
}
}
}
注入Func ：这似乎给了我类似的结果，具有更好的可读性。
[CommandMethod("Test", CommandFlags.Session)]
public void Test()
{
PerformActionOnBlockTable(AddLineToDrawing);
PerformActionOnBlockTable(AddCircleToDrawing);
}
private void PerformActionOnBlockTable(Func<BlockTableRecord, DBObject> action)
{
using (DocumentLock lockedDocument = Application.DocumentManager.MdiActiveDocument.LockDocument())
{
using (Database database = Application.DocumentManager.MdiActiveDocument.Database)
{
using (Transaction transaction = database.TransactionManager.StartTransaction())//Start the transaction
{
//Open the block table for read
BlockTable blockTable = transaction.GetObject(database.BlockTableId, OpenMode.ForRead) as BlockTable;
//Open the block table record model space for write
BlockTableRecord blockTableRecord = (BlockTableRecord)transaction.GetObject(blockTable[BlockTableRecord.ModelSpace], OpenMode.ForWrite);
DBObject newObject = action(blockTableRecord);
transaction.AddNewlyCreatedDBObject(newObject, true);
transaction.Commit();
}
}
}
}
private DBObject AddLineToDrawing(BlockTableRecord blockTableRecord)
{
Line line = new Line(new Point3d(0, 0, 0), new Point3d(10, 10, 0));
blockTableRecord.AppendEntity(line);
return line;
}
private DBObject AddCircleToDrawing(BlockTableRecord blockTableRecord)
{
Circle circle = new Circle(new Point3d(0, 0, 0), new Vector3d(0, 0, 0), 10);
blockTableRecord.AppendEntity(circle);
return circle;
}
老实说，我对DI并没有做太多事情，所以我对此很陌生。你们中任何更有经验的开发人员可以给我两种不同方法的专业意见吗？最后一种方法中是否有任何危险的信号？它似乎比第二种方法更具可读性。也许我什至不完全了解注射剂...预先感谢您的输入！
参考方案
您可以进行简单的重构，而不是提供的选项：
[CommandMethod("Test", CommandFlags.Session)]
public void Test() {
AddLineToDrawing();
AddCircleToDrawing();
}
private void AddLineToDrawing() {
CreateObjectOnBlockTable(
new Line(new Point3d(0, 0, 0), new Point3d(10, 10, 0)));
}
private void AddCircleToDrawing() {
CreateObjectOnBlockTable(
new Circle(new Point3d(0, 0, 0), new Vector3d(0, 0, 0), 10));
}
private void CreateObjectOnBlockTable(DBObject dbObject) {
using (var lockedDocument = Application.DocumentManager.MdiActiveDocument.LockDocument())
using (var database = Application.DocumentManager.MdiActiveDocument.Database)
using (var transaction = database.TransactionManager.StartTransaction()) {
// Open the block table for read
var blockTable = (BlockTable)transaction.GetObject(database.BlockTableId, OpenMode.ForRead);
// Open the block table record model space for write
var blockTableRecord = (BlockTableRecord)transaction.GetObject(blockTable[BlockTableRecord.ModelSpace], OpenMode.ForWrite);
blockTableRecord.AppendEntity(dbObject);
transaction.AddNewlyCreatedDBObject(dbObject, true);
transaction.Commit();
}
}
我认为这更具可读性。
更新：为了运行特殊的逻辑，我喜欢使用委托的想法。我将这样重构代码：
private void CreateObjectOnBlockTable(DBObject dbObject) {
PerformActionOnBlockTable((transaction, blockTableRecord) => {
blockTableRecord.AppendEntity(dbObject);
transaction.AddNewlyCreatedDBObject(dbObject, true);
});
}
private void PerformActionOnBlockTable(Action<Transaction, BlockTableRecord> action) {
using (var lockedDocument = Application.DocumentManager.MdiActiveDocument.LockDocument())
using (var database = Application.DocumentManager.MdiActiveDocument.Database)
using (var transaction = database.TransactionManager.StartTransaction()) {
// Open the block table for read
var blockTable = (BlockTable)transaction.GetObject(database.BlockTableId, OpenMode.ForRead);
// Open the block table record model space for write
var blockTableRecord = (BlockTableRecord)transaction.GetObject(blockTable[BlockTableRecord.ModelSpace], OpenMode.ForWrite);
// Run specific logic
action(transaction, blockTableRecord);
transaction.Commit();
}
}
（其余代码将相同）
可以使用事务和块表记录重用PerformActionOnBlockTable来运行任意逻辑。
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