C# DxfDocument.RemoveEntity方法代码示例

        public static void ModifyingBlockProperties()
        {
            DxfDocument doc = new DxfDocument();
            doc.DrawingVariables.InsUnits = DrawingUnits.Centimeters;
            Line existingLine = new Line(new Vector2(-10, 10), new Vector2(10, -10));
            doc.AddEntity(existingLine);

            AttributeDefinition attDef4 = new AttributeDefinition("MyAttribute4");
            attDef4.Value = "MyValue4";
            attDef4.Alignment = TextAlignment.TopCenter;
            Block block = new Block("MyBlock", null, new List<AttributeDefinition>{attDef4});
            block.Record.Units = DrawingUnits.Millimeters;

            // this is incorrect we cannot add an entity that belongs to a document when the block does not belong to anyone.
            //block.Entities.Add(existingLine);
            doc.Blocks.Add(block);
            // when the block and the entity that is being added belong to the same document, the entity will be removed from its current layout and added to the block
            // you cannot add an entity that belongs to a different document or block. Clone it instead.
            block.Entities.Add(existingLine);

            // now we can modify the block properties even if it has been already added to the document
            Line line = new Line(new Vector2(-10, -10), new Vector2(10, 10));

            // when new entities that do not belong to anyone are added to an existing block, they will also be added to the document
            block.Entities.Add(line);

            DxfDocument doc2 = new DxfDocument();
            Circle circle = new Circle(Vector2.Zero, 5);
            doc2.AddEntity(circle);

            // this is incorrect the circle already belongs to another document
            //block.Entities.Add(circle);
            // we need to clone it first
            Circle circle2 = (Circle) circle.Clone();
            circle2.Radius = 2.5;
            block.Entities.Add(circle2);

            //you could also remove circle2 from doc2 and add it to the block
            doc2.RemoveEntity(circle);
            block.Entities.Add(circle);

            AttributeDefinition attDef = new AttributeDefinition("MyAttribute1");
            attDef.Value = "MyValue1";
            block.AttributeDefinitions.Add(attDef);

            // the same that is applicable to entities is also true to attribute definitions
            AttributeDefinition attDef2 = new AttributeDefinition("MyAttribute2");
            attDef2.Value = "MyValue2";
            attDef2.Alignment = TextAlignment.BaselineRight;
            block.AttributeDefinitions.Add(attDef2);

            Insert ins = new Insert(block);
            doc.AddEntity(ins);

            // if the insert has been added to a document, any new attribute definitions added to the block will not be reflected in the insert
            // this mimics the behavior in AutoCad
            AttributeDefinition attDef3 = new AttributeDefinition("MyAttribute3");
            attDef3.Value = "MyValue3";
            attDef3.Alignment = TextAlignment.TopCenter;
            block.AttributeDefinitions.Add(attDef3);
            ins.Rotation = 30;

            // to update the insert attributes call the method Sync, this method will also call the method TransformAttributes
            ins.Sync();

            // the ins2 will have all three attributes
            Insert ins2 = new Insert(block, new Vector2(20,0));
            doc.AddEntity(ins2);

            doc.Save("Test.dxf");

            block.Name = "MyBlockRenamed";

            doc.Save("BlockRename.dxf");

            doc = Test("BlockRename.dxf");
        }

        private static void RemoveBlock()
        {
            DxfDocument dxf = new DxfDocument();
            Block block = new Block("MyBlock");

            Line line1 = new Line(new Vector3(-5, -5, 0), new Vector3(5, 5, 0));
            Line line2 = new Line(new Vector3(5, -5, 0), new Vector3(-5, 5, 0));
            block.Entities.Add(line1);
            block.Entities.Add(line2);

            Insert insert = new Insert(block);

            dxf.AddEntity(insert);

            bool ok;
            // line1 is used by block and cannot be removed (ok = false)
            ok = dxf.RemoveEntity(line1);
            // block is used by insert and cannot be removed (ok = false)
            ok = dxf.Blocks.Remove(block);
            // it is safe to remove insert, it doesn't belong to anybody (ok = true)
            ok = dxf.RemoveEntity(insert);
            // it is safe to remove block, it doesn't belong to anybody (ok = true)
            // at the same time, all entities that were part of the block have been also removed
            ok = dxf.Blocks.Remove(block);
            // obj is null the line1 does not exist in the document, the block was removed
            DxfObject obj = dxf.GetObjectByHandle(line1.Handle);

            Console.WriteLine("Press a key...");
            Console.ReadKey();

        }

        private static void AppRegUsesAndRemove()
        {
            DxfDocument dxf = new DxfDocument();

            List<PolylineVertex> vertexes = new List<PolylineVertex>{
                                                                        new PolylineVertex(0, 0, 0), 
                                                                        new PolylineVertex(10, 0, 10), 
                                                                        new PolylineVertex(10, 10, 20), 
                                                                        new PolylineVertex(0, 10, 30)
                                                                        };

            Polyline poly = new Polyline(vertexes, true);

            XData xdata1 = new XData(new ApplicationRegistry("netDxf"));
            xdata1.XDataRecord.Add(new XDataRecord(XDataCode.String, "extended data with netDxf"));

            poly.XData.Add(xdata1);

            dxf.AddEntity(poly);

            Line line = new Line(new Vector2(10, 5), new Vector2(-10, -5));

            ApplicationRegistry myAppReg = new ApplicationRegistry("MyAppReg");
            XData xdata2 = new XData(myAppReg);
            xdata2.XDataRecord.Add(new XDataRecord(XDataCode.Distance, Vector3.Distance(line.StartPoint, line.EndPoint)));
            line.XData.Add(xdata2);

            dxf.AddEntity(line);

            Circle circle = new Circle(Vector3.Zero, 15);
            XData xdata3 = new XData(myAppReg);
            xdata3.XDataRecord.Add(new XDataRecord(XDataCode.Real, circle.Radius));
            circle.XData.Add(xdata3);

            dxf.AddEntity(circle);

            dxf.Save("appreg.dxf");

            DxfDocument dxf2 = DxfDocument.Load("appreg.dxf");

            // will return false the "MyAppReg" is in use
            bool ok;
            ok = dxf.ApplicationRegistries.Remove(myAppReg.Name);
            dxf.RemoveEntity(line);
            dxf.RemoveEntity(circle);
            // "MyAppReg" is not used anymore
            IList<DxfObject> uses = dxf.ApplicationRegistries.GetReferences(myAppReg.Name);
            // it is safe to delete it
            ok = dxf.ApplicationRegistries.Remove(myAppReg.Name);
            
            // we can even make a full cleanup
            dxf.ApplicationRegistries.Clear();

            dxf.Save("appreg2.dxf");


        }

        private static void AddAndRemove()
        {
            Layer layer1 = new Layer("layer1") { Color = AciColor.Blue };
            Layer layer2 = new Layer("layer2") { Color = AciColor.Green };

            Line line = new Line(new Vector2(0, 0), new Vector2(10, 10));
            line.Layer = layer1;
            Circle circle = new Circle(new Vector2(0, 0), 10);
            circle.Layer = layer2;

            double offset = -0.9;
            Vector3 p1 = new Vector3(1, 2, 0);
            Vector3 p2 = new Vector3(2, 6, 0);
            Line line1 = new Line(p1, p2);
            Vector3 l1;
            Vector3 l2;
            MathHelper.OffsetLine(line1.StartPoint, line1.EndPoint, line1.Normal, offset, out l1, out l2);

            DimensionStyle myStyle = new DimensionStyle("MyDimStyle");
            myStyle.DIMPOST = "<>mm";
            AlignedDimension dim1 = new AlignedDimension(p1, p2, offset, myStyle);

            //text
            TextStyle style = new TextStyle("MyTextStyle", "Arial.ttf");
            Text text = new Text("Hello world!", Vector3.Zero, 10.0f, style)
                            {
                                Layer = new Layer("text")
                                            {
                                                Color = {Index = 8}
                                            }
                            };
            text.Alignment = TextAlignment.TopRight;

            HeaderVariables variables = new HeaderVariables
                                            {
                                                AcadVer = DxfVersion.AutoCad2004
                                            };
            DxfDocument dxf = new DxfDocument();
            dxf.AddEntity(new EntityObject[] {line, circle, dim1, text});
            dxf.Save("before remove.dxf");

            dxf.RemoveEntity(circle);
            dxf.Save("after remove.dxf");

            dxf.AddEntity(circle);
            dxf.Save("after remove and add.dxf");

            dxf.RemoveEntity(dim1);
            dxf.Save("remove dim.dxf");

            dxf.AddEntity(dim1);
            dxf.Save("add dim.dxf");

            DxfDocument dxf2 = DxfDocument.Load("dim block names.dxf");
            dxf2.AddEntity(dim1);
            dxf2.Save("dim block names2.dxf");
        }

        private static void MLineStyleUsesAndRemove()
        {
            DxfDocument dxf = new DxfDocument();
            //MLineStyle style = MLineStyle.Default;
            //dxf.AddMLineStyle(style);

            List<Vector2> vertexes = new List<Vector2>
                                            {
                                                new Vector2(0, 0),
                                                new Vector2(0, 150),
                                                new Vector2(150, 150),
                                                new Vector2(150, 0)
                                            };

            MLine mline = new MLine(vertexes);
            mline.Scale = 20;
            mline.Justification = MLineJustification.Zero;
            //mline.IsClosed = true;

            MLineStyle style = new MLineStyle("MyStyle", "Personalized style.");
            style.Elements.Add(new MLineStyleElement(0.25));
            style.Elements.Add(new MLineStyleElement(-0.25));
            // if we add new elements directly to the list we need to sort the list,
            style.Elements.Sort();
            style.Flags = MLineStyleFlags.EndInnerArcsCap | MLineStyleFlags.EndRoundCap | MLineStyleFlags.StartInnerArcsCap | MLineStyleFlags.StartRoundCap;
            //style.StartAngle = 25.0;
            //style.EndAngle = 160.0;
            // AutoCad2000 dxf version does not support true colors for MLineStyle elements
            style.Elements[0].Color = new AciColor(180, 230, 147);
            mline.Style = style;
            // we have modified the mline after setting its vertexes so we need to manually call this method.
            // also when manually editting the vertex distances
            mline.Update();

            // we can manually create cuts or gaps in the individual elements that made the multiline.
            // the cuts are defined as distances from the start point of the element along its direction.
            mline.Vertexes[0].Distances[0].Add(50);
            mline.Vertexes[0].Distances[0].Add(100);
            mline.Vertexes[0].Distances[mline.Style.Elements.Count - 1].Add(50);
            mline.Vertexes[0].Distances[mline.Style.Elements.Count - 1].Add(100);
            dxf.AddEntity(mline);

            dxf.DrawingVariables.AcadVer = DxfVersion.AutoCad2004;
            dxf.Save("MLine.dxf");

            DxfDocument dxf2 = DxfDocument.Load("MLine.dxf");

            // "MyStyle" is used only once
            List<DxfObject> uses;
            uses = dxf.MlineStyles.GetReferences(mline.Style.Name);

            // if we try to get the LineTypeUses, we will find out that "MyStyle" appears several times,
            // this is due to that each MLineStyleElement of a MLineStyle has an associated LineType
            uses = dxf.LineTypes.GetReferences(LineType.ByLayerName);

            bool ok;
            ok = dxf.RemoveEntity(mline);

            // "MyStyle" is not used its reference has been deleted
            uses = dxf.MlineStyles.GetReferences(mline.Style.Name);
            // we can safely remove it
            dxf.MlineStyles.Remove(mline.Style.Name);

            dxf.Save("MLine2.dxf");

            dxf.Layers.Clear();

            dxf.Save("MLine2.dxf");
        }

        private static void TextAndDimensionStyleUsesAndRemove()
        {
            DxfDocument dxf = new DxfDocument();

            Layer layer1 = new Layer("Layer1");
            layer1.Color = AciColor.Blue;
            layer1.LineType = LineType.Center;

            Layer layer2 = new Layer("Layer2");
            layer2.Color = AciColor.Red;

            // blocks needs an special attention
            Layer layer3 = new Layer("Layer3");
            layer3.Color = AciColor.Yellow;

            Circle circle = new Circle(Vector3.Zero, 15);
            // it is always recommended that all block entities will be located in layer 0, but this is up to the user.
            circle.Layer = new Layer("circle");
            circle.Layer.Color = AciColor.Green;

            Block block = new Block("MyBlock");
            block.Entities.Add(circle);
            AttributeDefinition attdef = new AttributeDefinition("NewAttribute");

            block.AttributeDefinitions.Add(attdef);

            Insert insert = new Insert(block, new Vector2(5, 5));
            insert.Attributes[0].Style = new TextStyle("Arial.ttf");

            dxf.AddEntity(insert);

            dxf.Save("style.dxf");
            DxfDocument dxf2;
            dxf2 = DxfDocument.Load("style.dxf");

            dxf.RemoveEntity(circle);

            Vector3 p1 = new Vector3(0, 0, 0);
            Vector3 p2 = new Vector3(5, 5, 0);
            Line line = new Line(p1, p2);

            dxf.AddEntity(line);

            DimensionStyle myStyle = new DimensionStyle("MyStyle");
            myStyle.DIMTXSTY = new TextStyle("Tahoma.ttf");
            myStyle.DIMPOST = "<>mm";
            myStyle.DIMDEC = 2;
            double offset = 7;
            LinearDimension dimX = new LinearDimension(line, offset, 0.0, myStyle);
            dimX.Rotation += 30.0;
            LinearDimension dimY = new LinearDimension(line, offset, 90.0, myStyle);
            dimY.Rotation += 30.0;

            dxf.AddEntity(dimX);
            dxf.AddEntity(dimY);

            dxf.Save("style2.dxf");
            dxf2 = DxfDocument.Load("style2.dxf");


            dxf.RemoveEntity(dimX);
            dxf.RemoveEntity(dimY);

            bool ok;

            // we can remove myStyle it was only referenced by dimX and dimY
            ok = dxf.DimensionStyles.Remove(myStyle.Name);

            // we cannot remove myStyle.TextStyle since it is in use by the internal blocks created by the dimension entities
            ok = dxf.Blocks.Remove(dimX.Block.Name);
            ok = dxf.Blocks.Remove(dimY.Block.Name);

            // no we can remove the unreferenced textStyle
            ok = dxf.TextStyles.Remove(myStyle.DIMTXSTY.Name);

            dxf.Save("style3.dxf");
            dxf2 = DxfDocument.Load("style3.dxf");
        }

        private static void LayerAndLineTypesUsesAndRemove()
        {
            DxfDocument dxf = new DxfDocument();

            Layer layer1 = new Layer("Layer1");
            layer1.Color = AciColor.Blue;
            layer1.LineType = LineType.Center;

            Layer layer2 = new Layer("Layer2");
            layer2.Color = AciColor.Red;

            LwPolyline poly = new LwPolyline();
            poly.Vertexes.Add(new LwPolylineVertex(0, 0));
            poly.Vertexes.Add(new LwPolylineVertex(10, 10));
            poly.Vertexes.Add(new LwPolylineVertex(20, 0));
            poly.Vertexes.Add(new LwPolylineVertex(30, 10));
            poly.Layer = layer1;
            dxf.AddEntity(poly);

            Ellipse ellipse = new Ellipse(new Vector3(2, 2, 0), 5, 3);
            ellipse.Rotation = 30;
            ellipse.Layer = layer1;
            dxf.AddEntity(ellipse);

            Line line = new Line(new Vector2(10, 5), new Vector2(-10, -5));
            line.Layer = layer2;
            line.LineType = LineType.DashDot;
            dxf.AddEntity(line);


            bool ok;

            // this will return false since layer1 is not empty
            ok = dxf.Layers.Remove(layer1.Name);

            List<DxfObject> entities = dxf.Layers.GetReferences(layer1.Name);
            foreach (DxfObject o in entities)
            {
                dxf.RemoveEntity(o as EntityObject);
            }

            // now this should return true since layer1 is empty
            ok = dxf.Layers.Remove(layer1.Name);

            // blocks needs an special attention
            Layer layer3 = new Layer("Layer3");
            layer3.Color = AciColor.Yellow;

            Circle circle = new Circle(Vector3.Zero, 15);
            // it is always recommended that all block entities will be located in layer 0, but this is up to the user.
            circle.Layer = new Layer("circle");
            circle.Layer.Color = AciColor.Green;

            Block block = new Block("MyBlock");
            block.Entities.Add(circle);
            block.Layer = new Layer("blockLayer");
            AttributeDefinition attdef = new AttributeDefinition("NewAttribute");
            attdef.Layer = new Layer("attDefLayer");
            attdef.LineType = LineType.Center;
            block.AttributeDefinitions.Add(attdef);

            Insert insert = new Insert(block, new Vector2(5, 5));
            insert.Layer = layer3;
            insert.Attributes[0].Layer = new Layer("attLayer");
            insert.Attributes[0].LineType = LineType.Dashed;
            dxf.AddEntity(insert);

            dxf.Save("test.dxf");

            DxfDocument dxf2 = DxfDocument.Load("test.dxf");

            // this list will contain the circle entity
            List<DxfObject> dxfObjects;
            dxfObjects = dxf.Layers.GetReferences("circle");

            // but we cannot removed since it is part of a block
            ok = dxf.RemoveEntity(circle);
            // we need to remove first the block, but to do this we need to make sure there are no references of that block in the document
            dxfObjects = dxf.Blocks.GetReferences(block.Name);
            foreach (DxfObject o in dxfObjects)
            {
                dxf.RemoveEntity(o as EntityObject);
            }


            // now it is safe to remove the block since we do not have more references in the document
            ok = dxf.Blocks.Remove(block.Name);
            // now it is safe to remove the layer "circle", the circle entity was removed with the block since it was part of it
            ok = dxf.Layers.Remove("circle");

            // purge all document layers, only empty layers will be removed
            dxf.Layers.Clear();

            // purge all document line types, only line types without references will be removed
            dxf.LineTypes.Clear();

            dxf.Save("test2.dxf");
        }

        private static void ImageUsesAndRemove()
        {
            ImageDefinition imageDef1 = new ImageDefinition("img\\image01.jpg");
            Image image1 = new Image(imageDef1, Vector3.Zero, 10, 10);

            ImageDefinition imageDef2 = new ImageDefinition("img\\image02.jpg");
            Image image2 = new Image(imageDef2, new Vector3(0, 220, 0), 10, 10);
            Image image3 = new Image(imageDef2, image2.Position + new Vector3(280, 0, 0), 10, 10);

            Block block =new Block("MyImageBlock");
            block.Entities.Add(image1);

            Insert insert = new Insert(block);

            DxfDocument dxf = new DxfDocument();
            dxf.AddEntity(insert);
            dxf.AddEntity(image2);
            dxf.AddEntity(image3);
            dxf.Save("test netDxf.dxf");

           
            dxf.RemoveEntity(insert);
            dxf.Blocks.Remove(insert.Block.Name);
            // imageDef1 has no references in the document
            List<DxfObject> uses = dxf.ImageDefinitions.GetReferences(imageDef1.Name);
            dxf.Save("test netDxf with unreferenced imageDef.dxf");
            dxf = DxfDocument.Load("test netDxf with unreferenced imageDef.dxf");

            // once we have removed the insert and then the block that contained image1 we don't have more references to imageDef1
            dxf.ImageDefinitions.Remove(imageDef1.Name);
            dxf.Save("test netDxf with deleted imageDef.dxf");

        }

        private static void PaperSpace()
        {
            // Sample on how to work with Layouts
            DxfDocument dxf = new DxfDocument();
            // A new DxfDocument will create the default "Model" layout that is associated with the ModelSpace block. This layout cannot be erased or renamed.
            Line line = new Line(new Vector2(0), new Vector2(100));
            // The line will be added to the "Model" layout since this is the active one by default.
            dxf.AddEntity(line);

            // Create a new Layout, all new layouts will be associated with different PaperSpace blocks,
            // while there can be only one ModelSpace multiple PaperSpace blocks might exist in the document
            Layout layout1 = new Layout("Layout1");

            // When the layout is added to the list, a new PaperSpace block will be created automatically
            dxf.Layouts.Add(layout1);
            // Set this new Layout as the active one. All entities will now be added to this layout.
            dxf.ActiveLayout = layout1.Name;

            // Create a viewport, this is the window to the ModelSpace
            Viewport viewport1 = new Viewport
                {
                    Width = 100,
                    Height = 100,
                    Center = new Vector3(50, 50, 0),
                };

            // Add it to the "Layout1" since this is the active one
            dxf.AddEntity(viewport1);
            // Also add a circle
            Circle circle = new Circle(new Vector2(150), 25);
            dxf.AddEntity(circle);

            // Create a second Layout, add it to the list, and set it as the active one.
            Layout layout2 = new Layout("Layout2");
            dxf.Layouts.Add(layout2);
            dxf.ActiveLayout = layout2.Name;

            // viewports might have a non rectangular boundary, in this case we will use an ellipse.
            Ellipse ellipse = new Ellipse(new Vector2(100), 200, 150);
            Viewport viewport2 = new Viewport
            {
                ClippingBoundary = ellipse,
            };

            // Add the viewport to the document. This will also add the ellipse to the document.
            dxf.AddEntity(viewport2);

            Layout layout3 = new Layout("AnyName");
            dxf.Layouts.Add(layout3);
            //layout can also be renamed
            layout3.Name = "Layout3";
            
            //dxf.Layouts.Remove(layout2.Name);

            ShowDxfDocumentInformation(dxf);

            // Save the document as always.
            dxf.Save("PaperSpace.dxf");

#region CAUTION - This is subject to change in the future, use it with care

            // You cannot directly remove the ellipse from the document since it has been attached to a viewport
            bool ok = dxf.RemoveEntity(ellipse); // OK = false

            // If an entity has been attached to another, its reactor will point to its owner
            // This information is subject to change in the future to become a list, an entity can be attached to multiple objects;
            // but at the moment only the viewport clipping boundary make use of this.
            // This is the way AutoCad also handles hatch and dimension associativity, that I might implement in the future
            DxfObject reactor = ellipse.Reactors[0]; // in this case reactor points to viewport2

            // You need to delete the viewport instead. This deletes the viewport and the ellipse
            //dxf.RemoveEntity(viewport2);

            // another way of deleting the ellipse, is first to assign another clipping boundary to the viewport or just set it to null
            viewport2.ClippingBoundary = null;
            // now it will be possible to delete the ellipse. This will not delete the viewport.
            ok = dxf.RemoveEntity(ellipse); // OK = true

            // Save the document if you want to test the changes
            dxf.Save("PaperSpace.dxf");

#endregion

            DxfDocument dxfLoad = DxfDocument.Load("PaperSpace.dxf");

            // For every entity you can check its layout
            // The entity Owner will return the block to which it belongs, it can be a *Model_Space, *Paper_Space, ... or a common block if the entity is part of its geometry.
            // The block record stores information about the block and one of them is the layout, this mimics the way the dxf stores this information.
            // Remember only the internal blocks *Model_Space, *Paper_Space, *Paper_Space0, *Paper_Space1, ... have an associated layout,
            // all other blocks will return null is asked for block.Record.Layout
            Layout associatedLayout = dxfLoad.Lines[0].Owner.Record.Layout;

            // or you can get the complete list of entities of a layout
            foreach (Layout layout in dxfLoad.Layouts)
            {
                List<DxfObject> entities = dxfLoad.Layouts.GetReferences(layout.Name); 
            }

            // You can also remove any layout from the list, except the "Model".
            // Remember all entities that has been added to this layout will also be removed.
//.........这里部分代码省略.........