Value cannot be null. (Parameter 'path1')

[FROMCITRUS]

Using .NET 5 publishing to win-x64

Value cannot be null. (Parameter 'path1')
   at System.IO.Path.Combine(String path1, String path2)
   at libplctag.NativeImport.LibraryExtractor.LibraryExists(String folder)
   at libplctag.NativeImport.LibraryExtractor.Init(Boolean forceExtract)
   at libplctag.NativeImport.plctag.ExtractLibraryIfRequired()
   at libplctag.NativeImport.plctag.plc_tag_create(String lpString, Int32 timeout)
   at libplctag.NativeTag.plc_tag_create(String lpString, Int32 timeout)
   at libplctag.NativeTagWrapper.Initialize()
   at libplctag.NativeTagWrapper.Read()
   at libplctag.Tag`2.Read()

Which traces to this line. https://github.com/libplctag/libplctag.NET/blob/ad6abb8f78275d3a6938ca0c4b3033dcef856fae/src/libplctag.NativeImport/LibraryExtractor.cs#L42

This occurs only with a published .exe file. This is caused by https://github.com/libplctag/libplctag.NET/blob/ad6abb8f78275d3a6938ca0c4b3033dcef856fae/src/libplctag.NativeImport/LibraryExtractor.cs#L29

returning an empty string.

My suggestion would be to swap out https://github.com/libplctag/libplctag.NET/blob/ad6abb8f78275d3a6938ca0c4b3033dcef856fae/src/libplctag.NativeImport/LibraryExtractor.cs#L31 with string location = System.AppContext.BaseDirectory; as the AppContext returns a valid location with the publish

[timyhac]

Interesting, my own application is the same .NET5 published to win-x64 and it works ok. The framework of my application is WPF.

What framework is your application using?

[FROMCITRUS]

I'm running a WinForms app. My bad, I meant to mention that initially. I am also configured to publish self-contained with ReadyToRun and single file enabled, and I copy over the dll with ForceExtractLibrary set to false.

[jkoplo]

I've had 'single file' publish play havoc with a lot of path stuff, including my 'appsettings.json' in ASP.NET services.

If the path solution above works that'd be great.

[timyhac]

There is a pull request that implements this change ready to merge. The only thing left to do is run this change through the environments to see if there are any regressions.

[timyhac]

Hi @FROMCITRUS - could you try this with latest alpha release?

[FROMCITRUS]

The libplctag 1.1.0-alpha.1 doesn't seem to have the fix, so I brought in libplctag.NativeImport 1.0.29. That seems to work as long as it isn't in a Release config with ReadyToRun compilation enabled. If both of those are set, then an exception occurs on the first usage of NativeImport

System.IO.FileNotFoundException: 
File name: 'libplctag.NativeImport, Version=1.0.29.0, Culture=neutral, PublicKeyToken=null'

In my specific case, the exception occured on the line libplctag.NativeImport.plctag.ForceExtractLibrary = false; I've been fighting .NET to get any more information out of the exception, but it has been difficult as it only fails in Release, not in Debug.

[jkoplo]

I'm actually seeing something similar (though not quite the same) on a single file publish. In debug it gets a path. In a simple release it gets a path. In single file (.net 6) the path returned is null and I get an exception.

I'll check my libplctag native version - I didn't explicitly pull it in so it's probably referencing an older release.

[jkoplo]

This is related to #259

[timyhac]

The original issue has been fixed and released, and the second issue seems to have significant overlap with #259 so I will close this one.