VSTO Add-in and .Net Framework version?

Question

Hello,

I have a question related to the .NET Framework version executed by a VSTO Add-in.

Stated here in this link https://docs.microsoft.com/en-us/dotnet/framework/migration-guide/version-compatibility :

"An app can control the version of the .NET Framework on which it runs, but a component cannot. Components and class libraries are loaded in the context of a particular app, and therefore automatically run on the version of the .NET Framework that the app runs on."

So my questions are as follow :

- Is a VSTO Excel Add-in considered as a component or an application, knowing that when we say COM Add-in : Compoenent Object Model Add-in ?

- In the case that a VSTO Add-in is targetting 4.5.1 NET Framework, and that the OS machine is using for example 4.7 => When runing, does the VSTO add-in runs 4.5.1 or 4.7 NET framework ?

Thank you in advance.

Answer 1

Hello Hamza,

1. Add-ins are considered as components to host applications like Excel, Word, Outlook and etc. You can create a configuration file for the host application and specify which version of .net framework you would like to be loaded. However,  unmanaged loaders (shims) of COM add-ins may load their own .net framework versions.

2. .Net framework 4.7 is an in-place upgrade of 4.5. So, there is no need to install anything on a machine with 4.7 .Net framework installed. Moreover, you need to care about CLR version, not BCL (.net framework).  

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Answer 2

Hello Hamza_Nouri,

Has your original issue been resolved? If it has, I would suggest you mark the helpful reply as answer or provide your solution and mark as answer to close this thread. If not, please feel free to let us know your current issue.

Best Regards,

Terry

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MSDN Community Support
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