19. April 2018 07:50
Normally, the best way to open Arduino projects in Visual Studio is to use standard Visual Studio commands such as 'File>Recent'.
This applies after the project has been created for the first time using Visual Micro commands such as "File>Open>Arduino Project", "File>New>Arduino Project". IE: You must have a Solution (.sln) to be able to open a Solution. Normally Arduino just has .ino/cpp etc. which is why Visual Micro commands auto create and configure solutions for you, but this only needs to happen once per project.
When opening projects make sure you open the Solution (.sln) (not .ino file) when you re-open projects. Opening an existing Solution will retain your previous "window layout" and "selected configuration" etc.
If you do not see your "Solution" on the "File>Recent" menu, then click the Solution to activate it in the explorer, then click "File>Save As". Saving the Solution (even with same name) will force it onto the Visual Studio "Recent" menus.
When your Solution is on the Recent menu you will have no need to use "File>Open Arduino" project, which is normally just used the first time you open an existing Arduino project in VS.