using CADImport;
 using CADImport.DWG;
 using CADImport.DXF;
 using CADImport.RasterImage;

         private void Change_layers_Click(object sender, EventArgs e)
         {
             //CADImage.CreateImageByExtension detects format by the extension specified in the argument. 
             //The correct class for any supported format will be used automatically. We recommend to
             //create a new drawing object with CADImage.CreateImageByExtension if import from the existed
             //file/stream is required.
             CADImage vDrawing = CADImage.CreateImageByExtension(@"..\..\..\Files\Entities.dxf");
             vDrawing.LoadFromFile(@"..\..\..\Files\Entities.dxf");
             // Changes color for Layer '0'
 	        vDrawing.Converter.LayerByName("0").Color = Color.Red;
             // If Layer2 doesn't exist, it will be created
 	        CADLayer vLayer = vDrawing.Converter.LayerByName("Layer2");
 	        vLayer.Visible = false; //Changes layer visibility
             // Adjusting visualization sizes to the control area:
             RectangleF vRect;
             double vRatio = (double)(vDrawing.AbsHeight * Image1.ClientSize.Width) / (vDrawing.AbsWidth * Image1.ClientSize.Height);
             if (vRatio > 1)
                 vRect = new RectangleF(0, 0, (float)(Image1.ClientSize.Width / vRatio), (float)Image1.ClientSize.Height);
             else
                 vRect = new RectangleF(0, 0, (float)Image1.ClientSize.Width, (float)(Image1.ClientSize.Height * vRatio));
             //-----------------------------------------------
             vDrawing.Draw(Image1.CreateGraphics(), vRect);
         }