问题
Only Visual Studio 2019 is present in VSIXInstaller, Visual Studio 2017 is missing and when I want to install the extension specifically for Visual Studio 2017 I can't do that
回答1:
I believe this issue crops up due to the 'Visual Studio Extension File' not having the appropriate supported VS Version Numbers specified in the '.vsixmanifest'.
(Changing the supported Version Number range will allow support for previous or future versions of Visual Studio.)
Here is a Link to an answer of mine which covers the issue and resolution. (Which has a worked example of allowing VS 2015 where only VS 2012 was supported)
来源：https://stackoverflow.com/questions/55670384/cant-install-the-extension-on-visual-studio-2017-after-installing-visual-studio