A technical application can host the control as its drawing surface. The control reads the file, draws it in the units of the drawing, and returns the point under the pointer, the entity nearest to a click, and the entities inside a rectangle. The host program uses those values for quoting, inspection, nesting, fabrication and printing.
The drawing
ReadDXF, ReadDWG and the DXF document
ReadDXF and ReadDWG replace the current drawing and display it. The DXF property is the document: entities, layers, blocks and drawing variables. WriteDXF and WriteDWG save that document, so the application can open a customer file, change it and return a DXF or DWG.
dxfReaderNETControl1.ReadDXF(@"C:\jobs\part.dxf");
foreach (Layer layer in dxfReaderNETControl1.DXF.Layers) { // layer.Name, layer.IsVisible }
Coordinates
CoordsToWorld and WorldToCoords
CoordsToWorld converts a pixel of the control into a point in drawing units. WorldToCoords does the opposite, so a computed point can be shown at the right place on screen. DXF.ToFormattedUnit formats a length with the precision stored in the drawing. ShowDrawingUnits opens the dialog for length and angle units: decimal, engineering, architectural, fractional, scientific, degrees, gradians and radians.
Vector2 world = dxfReaderNETControl1.CoordsToWorld(e.X, e.Y);
string text = dxfReaderNETControl1.DXF.ToFormattedUnit(world.X);
Selection
GetEntity and GetEntities
GetEntity returns the entity nearest to a point in drawing units. GetEntities returns the entities inside a rectangle defined by two corners. With HighlightEntityOnHover the entity under the pointer is emphasized before the user clicks.
| Method | Use in the application |
|---|
| GetEntity |
Identify the part, hole or contour the user clicked |
| GetEntities |
Collect the geometry inside a window, for a batch operation |
| HighlightEntityOnHover |
Show which entity will be picked |
Vector2 point = dxfReaderNETControl1.CoordsToWorld(e.X, e.Y);
EntityObject entity = dxfReaderNETControl1.GetEntity(point);
List<EntityObject> inside = dxfReaderNETControl1.GetEntities(corner1, corner2);
Precise points
ObjectOsnapMode
ObjectSnap turns object snap on. ObjectOsnapMode chooses the points the pointer locks to. Several modes are combined with a bitwise OR. ObjectOsnapTypeFlags.None clears them.
| ObjectOsnapTypeFlags | Locks to |
|---|
| Endpoint |
End points of lines and arcs, and polyline vertices |
| Midpoint |
Midpoint of a line, an arc or a polyline segment |
| Center |
Center of a circle, an arc or a polyline arc |
| GeometricCenter |
Geometric center of a polyline or a 2D spline |
| Quadrant |
The four quadrant points of a circle or an ellipse |
| Intersection |
Intersection of two entities |
| Insertion |
Insertion point of a block, a text or an image |
| Perpendicular |
The perpendicular point on the entity |
| Tangent |
The tangent point on a circle, an arc or an ellipse |
| Nearest |
The nearest point on the entity |
| Node |
A point entity |
| Vertex |
The closest vertex of a polyline |
dxfReaderNETControl1.ObjectSnap = true;
dxfReaderNETControl1.ObjectOsnapMode = ObjectOsnapTypeFlags.Endpoint | ObjectOsnapTypeFlags.Midpoint | ObjectOsnapTypeFlags.Intersection;
Area and perimeter
FindClosedAreaData
MathHelper.FindClosedAreaData reads a set of entities and returns the outer perimeter, the outer area, the total length and area of the holes, and the number of inner contours. The filled area is the outer area minus the inner area. An estimating, coating or nesting program uses these numbers directly, and ShowFilledAreas paints the recognized regions on the drawing.
double externalLength, externalArea, internalLength, internalArea; int holes;
bool found = MathHelper.FindClosedAreaData( dxfReaderNETControl1.DXF.Entities, out externalLength, out externalArea, out internalLength, out internalArea, out holes);
double filled = externalArea - internalArea;
Dimensions
Dimensions written into the drawing
The control adds the dimensions a technical drawing needs. Each method takes the measured geometry, an offset or a position for the dimension line, and an optional dimension style and layer.
| Method | What it measures |
|---|
| AddLinearDimension |
Horizontal, vertical or rotated distance between two points |
| AddAlignedDimension |
Distance along the direction of two points or a line |
| AddAngularDimension |
Angle between two lines, or the angle of an arc |
| AddRadialDimension |
Radius of a circle or an arc |
| AddDiametricDimension |
Diameter of a circle or an arc |
| AddArcLengthDimension |
Length of an arc |
| AddLeader |
A leader with an annotation |
dxfReaderNETControl1.AddLinearDimension(startPoint, endPoint, 10);
dxfReaderNETControl1.AddRadialDimension(circle, 15);
Interactive input
Rubber-band feedback
While the user picks points, the control can draw a temporary line, rectangle, circle, arc, polygon or dimension with ShowRubberBandLine, ShowRubberBandBox, ShowRubberBandCircle, ShowRubberBandArc, ShowRubberBandPolygon and ShowRubberBandLinearDimension. The temporary figure follows the pointer. When the input is complete, the application stores the real entity, for example with AddLine.
dxfReaderNETControl1.ShowRubberBandLine(anchor, current);
dxfReaderNETControl1.AddLine(anchor, current);
Fabrication files and models
NC1, STEP, IFC and OBJ
The same surface displays the files a technical workflow already uses. Each read method replaces the current drawing with the geometry of the file.
| Method | File | What the control produces |
|---|
| ReadNC1 |
NC1, starting with the ST block |
The plate geometry. ShowDimensions adds dimensions. ShowFilledArea fills the inner region |
| ReadSTEP |
STEP AP214 / AP203 |
Edge curves as lines, circles and 3D polylines, grouped by part name |
| ReadIFC |
IFC, IFCZIP |
One mesh per product, a layer per class, groups by building storey |
| ReadOBJ |
Wavefront OBJ |
The vertices and faces of the mesh |
dxfReaderNETControl1.ReadNC1(@"C:\jobs\plate.nc1", true, true);
Print and exchange
Plot, Image and WriteSVG
Plot sends the current view to a printer. PlotPreview draws it into a PrintPreviewControl. ShowPlotSettings opens the plot dialog. The Image property is the bitmap of the view, ready to archive or to place in a report. WriteSVG writes the drawing for a page that has to stay vectorial. PlotRendering chooses color, gray scale or monochrome output.
dxfReaderNETControl1.PlotRendering = PlotRenderingType.Monochrome;
dxfReaderNETControl1.Plot();
dxfReaderNETControl1.WriteSVG(@"C:\jobs\part.svg");