Creating a Tif from the EMF Stream

I'm working with the console application provided by Walter linked from the white paper Extend Existing Applications with the LEADTOOLS Virtual Printer SDK. It creates 3 image formats - a .emf, a .pdf, and a .png. I need a tiff file as well so I copied the method for .png and made what I thought were necessary changes, but it ends with an error at the line metaFile = new Metafile(e.Stream) below in blue

{System.Runtime.InteropServices.ExternalException (0x80004005): A generic error occurred in GDI+.
at System.Drawing.Imaging.Metafile..ctor(Stream stream)
at Virtual_Printer_Driver_Sample.EmfEventMethods.FillSection_Tif(Object sender, EmfEventArgs e) in c:\Users\bwilliams\Desktop\LeadTools Eval License\Virtual Printer Driver Console\Virtual Printer Driver Sample\EmfEventMethods.cs:line 130}

Here is the method. what do I need to do to get the code working?

[EmfEventMethodAttribute]
public static void FillSection_Tif(object sender, Leadtools.Printer.EmfEventArgs e)
{
ConsoleMethods.Info("EMF Event: FillSection_Tif");
const string format = "tif";
string path = Path.Combine(
GetOutputRootPath(),
format + @"\",
GetRandomFileName(format));
Directory.CreateDirectory(Path.GetDirectoryName(path));
// Get the EMF in memory and save as TIF.
Metafile metaFile = null;
try
{
metaFile = new Metafile(e.Stream);
IntPtr hEmf = metaFile.GetHenhmetafile();
using (RasterImage image = RasterImageConverter.FromEmf(hEmf, 0, 0, RasterColor.White))
{
using (RasterRegion region = new RasterRegion(new LeadRect(20, 30, 100, 200)))
{
image.SetRegion(null, region, RasterRegionCombineMode.Set);
new FillCommand(RasterColor.FromKnownColor(RasterKnownColor.Black)).Run(image);
}
using (RasterCodecs codecs = new RasterCodecs())
{
codecs.Save(image, path, RasterImageFormat.Tif, 1);
}
}
ConsoleMethods.Success("FillSection_Png: TIF saved. ");
ConsoleMethods.Verbose(path);
}
catch (Exception ex)
{
ConsoleMethods.Error(ex.Message, 4000);
}
}
}

Edited by moderator Friday, October 7, 2016 4:37:21 PM(UTC)  | Reason: added link to whitepaper

Hello,

I think the problem you're having is the memory stream position is being incremented to the end of the file by the prior conversions. I first tried removing the other conversions and creating the TIFF file worked. Then I saw the problem you noted with the EMF file in memory. After setting the position back to 0 immediately before using the stream, the conversion completed successfully for me. So all I had to do was add the following line:

// Get the EMF in memory and save as TIF.
Metafile metaFile = null;
try
{
e.Stream.Position = 0;
metaFile = new Metafile(e.Stream);

I'm attaching the updated 2010 project here for reference.

Thanks Walter - got it working.

Quick question - why don't you have to rewind the stream after saving the EMF stream directly, creating the PDF and PNG?

That I'm not really sure of. If they're sharing the MemoryStream like they seem to be, then I would also expect you'd need to set the position each time to ensure it always starts at the beginning, or at least for each subsequent time after the first. Why it works a couple of times and then fails is a mystery to me as well.