Q&A - Question

Hello everybody ,

i'm trying to Export an Image of the Visible GisViewer.

I'm using this code from the Example

http://docs.tatukgis.com/DK11/samples:src:vcl:pas:viewer:mainform_pas


But it gives me an Access Violation cause lp is nil after
 

lp := GisCreateLayer( path, path ) as TGIS_LayerPixel ; 

Any Idea why lp is nil ?

 

 lp := GisCreateLayer( path, path ) as TGIS_LayerPixel ;
  try
    sf := TGIS_LayerPixelSubFormat.Create(
            TGIS_PixelFormat.RGB,
            False,
            sub,
            comp,
            90
          ) ;
    lp.Build( lp.Path, False, GIS.CS, ex, w, h, sf  ) ;
 
    pem := TGIS_PixelExportManager.Create( lp ) ;
    try
      pem.BusyEvent := GISBusy ;
      vbmp := TGIS_ViewerBmp.Create( 512, 512 ) ;
      try
        vbmp.PaintExtraEvent := GIS.PaintExtraEvent ;
        pem.ExportFrom( GIS, vbmp, ex, w, h, dpi ) ;
      finally
        vbmp.Free ;
      end;
    finally
      pem.Free ;
    end;
  finally
    lp.SaveData ;
    lp.Free ;
  end;