Change layers procedure

uses DXF, DXFConv;

...

type

  TForm1 = class(TForm)

    Image1: TImage;

...

implementation

procedure TForm1.ChangeLayersClick(Sender: TObject);

var
  // a reading class for DXF format
  // Please use a correspond class to read a drawing of other format.
  // For example TsgDWGImage for DWG format, TsgCGMImage for CGM, etc.
  vDrawing: TsgCADDXFImage; 
  vLayer: TsgDXFLayer; // a class for Layers

begin
  vDrawing := TsgCADDXFImage.Create;
  vDrawing.LoadFromFile('Entities.dxf');

  // change color of Layer '0'

  vDrawing.Converter.LayerByName('0').Color := clRed;

  // if layer does not exist, new layer will be created

  vLayer := vDrawing.Converter.LayerByName('Layer2');

  vLayer.Visible := False; //change layer visibility

  Image1.Picture.Graphic := nil;

  Image1.Canvas.StretchDraw(Rect(0, 0,

    Round(vDrawing.Width * Image1.Height / vDrawing.Height), Image1.Height), vDrawing);

  vDrawing.Free;

end;