I've been using iTextSharp with regular dotnet applications for a while now. We're interested in using it with dotnet core. But it seems that the library is still not supported on the new dotnet core platform:
Package iTextSharp 5.5.10 is not compatible with netstandard1.6
Do you plan to support dotnet core in a future release?
For the record: I am an employee at iText Software.
Currently, .NET Core and the related UWP standard are not supported by any iText projects. We have done investigations into both these new technologies and have found that there are significant issues with supporting them, because of drastic modifications in certain components of the .NET Core software stack. You can read https://stackoverflow.com/a/34612369/2065017 for more details about my initial investigation into UWP; the problems with .NET Core are very similar.
If and when .NET Core will be supported, it will probably only be in our new project iText 7, which is not backwards compatible to iText 5 (also known as iTextSharp). The reason for this is that iText 5 is now only on maintenance, i.e. bugfix releases, as it is being supplanted by iText 7 in the user community.
iText 7 for .NET (meaning only the .NET Framework) is actually an automated port of iText 7 for Java, using the tool Sharpen. This takes away the possibility of many nasty lingering bugs that used to pop up in iTextSharp 5 because of porting omissions or errors. We are currently looking if there is any way to duplicate this workflow for .NET Core so that we can support this without having to do manual porting and manual maintenance. I regret to inform you that we have not found any such tool yet, so we may have to investigate building a Sharpen-like tool ourselves. This is currently, perhaps unsurprisingly, not our biggest priority as a company.
来源：https://stackoverflow.com/questions/40236194/itextsharp-any-support-for-dotnet-core-netstandard1-6