Open file in existing instance of Visual Studio 2017

Question

I used to be able to open a file in an existing instance of VS - devenv.exe had a /dde switch for that.

But with VS2017 it opens the file in a new instance, not the one already running.

For example for json files:

My registry has a key HKEY_CLASSES_ROOT\.json\OpenWithProgids which contains a value VisualStudio.json.
And there is a key HKEY_CLASSES_ROOT\VisualStudio.json\shell\Open\Command which contains the default value "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\devenv.exe" /dde.

But that /dde is ignored.

Maybe all the betas and RCs corrupted something. My VS2017 is the latest updated version.

Does the /dde switch still work?

user_17090852 · Answer

I had the same problem with visual studio 2019 and windows 11. I thought manipulating the registry was overkill, so I looked for a workaround.

Just create a .bat file with the following contents and select that .bat file from "Select Another Program".

start "" "C:\Program Files (x86)\Common Files\Microsoft Shared\MSEnv\VSLauncher.exe" /edit %1