DGN Drawing

Drawing DGN Format As Part of DWG

Aspose.CAD for .NET allows developers to export a DWG file with embedded DGN inside. Following is the code demonstrating how to access the DGN inside a DWG file while exporting the DWG file.

Sample Code

// The path to the documents directory.
string MyDir = RunExamples.GetDataDir_ConvertingCAD();
string[] sourceFilePaths = new[] 
{
    MyDir + "conic_pyramid.dxf",
    MyDir + "Bottom_plate.dwg"
};

foreach (var sourceFilePath in sourceFilePaths)
{
    string extension = Path.GetExtension(sourceFilePath);
    using (CadImage cadImage = (CadImage)Aspose.CAD.Image.Load(sourceFilePath))
    {
        List<string> layouts = GetNotEmptyLayouts(cadImage, extension);
        const double Epsilon = 0.00001;
        foreach (string layout in layouts)
        {
            System.Console.WriteLine("Layout= " + layout);
            using (FileStream fs = new FileStream(MyDir + "layout_" + extension + "_" + layout + ".jpg", FileMode.Create))
            {
                JpegOptions jpegOptions = new JpegOptions();
                CadRasterizationOptions options = new CadRasterizationOptions();
                options.Layouts = new string[] { layout };

                CadLayout l = cadImage.Layouts[layout];

                if ((Math.Abs(l.MaxExtents.Y) < Epsilon && Math.Abs(l.MaxExtents.X) < Epsilon)
                    || (Math.Abs(l.MaxExtents.Y + 1E+20) < Epsilon
                    || Math.Abs(l.MaxExtents.X + 1E+20) < Epsilon)
                    || (Math.Abs(l.MinExtents.Y - 1E+20) < Epsilon
                    || Math.Abs(l.MinExtents.X - 1E+20) < Epsilon))
                {
                    // do nothing, we can automatically detect size
                    // we can not rely on PlotPaperUnits here too because it is PlotInInches by default
                }
                else
                {
                    double sizeExtX = l.MaxExtents.X - l.MinExtents.X;
                    double sizeExtY = l.MaxExtents.Y - l.MinExtents.Y;

                    if (l.PlotPaperUnits == CadPlotPaperUnits.PlotInInches)
                    {
                        options.PageHeight = CommonHelper.INtoPixels(sizeExtY, CommonHelper.DPI);
                        options.PageWidth = CommonHelper.INtoPixels(sizeExtX, CommonHelper.DPI);
                    }
                    else
                    {
                        if (l.PlotPaperUnits == CadPlotPaperUnits.PlotInMillimeters)
                        {
                            options.PageHeight = CommonHelper.MMtoPixels(sizeExtY, CommonHelper.DPI);
                            options.PageWidth = CommonHelper.MMtoPixels(sizeExtX, CommonHelper.DPI);
                        }
                        else
                        {
                            options.PageHeight = (float)sizeExtY;
                            options.PageWidth = (float)sizeExtX;
                        }
                    }
                }

                
                jpegOptions.VectorRasterizationOptions = options;

                cadImage.Save(fs, jpegOptions);
            }
        }
    }
}
        }

private static List<string> GetNotEmptyLayouts(Image cadImage, string extension)
        {
List<string> nonEmptyLayouts = new List<string>();
if (cadImage == null)
    return nonEmptyLayouts;

switch (extension)
{
    case ".dwg":
        nonEmptyLayouts = GetNotEmptyLayoutsForDwg((CadImage)cadImage);
        break;
    case ".dxf":
        nonEmptyLayouts = GetNotEmptyLayoutsForDxf((CadImage)cadImage);
        break;
}

return nonEmptyLayouts;
        }

private static List<string> GetNotEmptyLayoutsForDwg(CadImage cadImage)
        {
List<string> notEmptyLayouts = new List<string>();

foreach (CadLayout layout in cadImage.Layouts.Values)
{
    foreach (CadBlockTableObject tableObject in cadImage.BlocksTables)
    {
        if (string.Equals(tableObject.HardPointerToLayout.Value, layout.ObjectHandle, StringComparison.InvariantCultureIgnoreCase))
        {
            if (cadImage.BlockEntities.ContainsKey(tableObject.BlockName))
            {
                CadBlockEntity cadBlockEntity = cadImage.BlockEntities[tableObject.BlockName];
                if (cadBlockEntity.Entities.Length > 0)
                    notEmptyLayouts.Add(layout.LayoutName);
            }
            break;
        }
    }
}

return notEmptyLayouts;
        }

private static List<string> GetNotEmptyLayoutsForDxf(CadImage cadImage)
        {
List<string> notEmptyLayouts = new List<string>();

Dictionary<string, string> layoutBlockHandles = new Dictionary<string, string>();
foreach (CadLayout layout in cadImage.Layouts.Values)
{
    if (layout.BlockTableRecordHandle != null)
        layoutBlockHandles.Add(layout.BlockTableRecordHandle, layout.LayoutName);
}

foreach (CadBaseEntity entity in cadImage.Entities)
{
    if (layoutBlockHandles.ContainsKey(entity.SoftOwner.Value))
    {
        string layoutName = layoutBlockHandles[entity.SoftOwner.Value];
        if (!notEmptyLayouts.Contains(layoutName))
            notEmptyLayouts.Add(layoutName);
    }
}

return notEmptyLayouts;
        }