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c#excel-dna

Excel DNA - Best Way to Use Config Transforms

I have a project, lets call it 'ProjectX' which needs to use Excel DNA. Development is successful, however, I am unable to resolve one issue. The project uses config transforms to update values in app.config when building for different environments, for example DEV, UAT, and PROD.

Here is the issue: When I build for a certain environment, like DEV, the app.config transforms as expected. However, ProjectX-AddIn64-packed.xll.config does NOT transform, and this is the config that Excel DNA is using inside the XLL. I'm not sure what to do, any help would be appreciated.

Constraints: I can only deploy one file, the XLL.

Things I Have Tried/Researched:

  1. Renaming app.config to ProjectX-AddIn64-packed.xll.config
  2. Using Visual Studio Build Events
  3. Editing ExcelDna.Build.props to try and override the default build/packaging process
Solution

  • App.config transforms are currently not supported in Excel-DNA, as of this writing. One workaround at the moment is to replace the .xll.config files with the contents of the .dll.config file at the end of the build, after the transformation has been applied.

    There are many different ways you can choose to do this file replacement... For example, you can run a script in a post-build event, or alternatively add a new MSBuild target to your .csproj file that runs after the ExcelDnaBuild task which copies the file(s).

    E.g.

    <Target Name="CopyAppConfig" AfterTargets="ExcelDnaBuild">
  <Copy SourceFiles="$(TargetPath).config" DestinationFiles="$(TargetDir)MyAddIn-AddIn.xll.config" />
  <Copy SourceFiles="$(TargetPath).config" DestinationFiles="$(TargetDir)MyAddIn-AddIn-packed.xll.config" />
  <Copy SourceFiles="$(TargetPath).config" DestinationFiles="$(TargetDir)MyAddIn-AddIn64.xll.config" />
  <Copy SourceFiles="$(TargetPath).config" DestinationFiles="$(TargetDir)MyAddIn-AddIn64-packed.xll.config" />
</Target>

    You can read more about this on our GitHub repo: