Hello everyone and thank you for the feedback. We are actively investigating ways to improve how Visual Studio handles project content. This suggestion falls into that category. Unfortunately, we will not be able to address this feedback for the Visual Studio 2015 release. We will update the community when our plans in this area have gained more clarity.
Visual Studio – VS IDE Project and Build Team
Just an update that this is well supported in the new project system used by .NET Core and .NET Standard in Visual Studio 2017, but we haven't done the work to support it for existing project types. Over time, we'll hopefully be able to move more project types over to the new project system once we work out any compat issues there.
Great idea Mark - we're working on making it possible to use this for other project types that are based on the new project system (like JS).
Unfortunately, it's not likely to be retrofitted to the existing C# project system. Over time though, we are working on improving compatibility and performance of the new project system and plan to (someday) support opening non-SDK projects with the new project system too.
This would be useful for this and a variety of other great features (live project editing, file-globbing support, etc).
Go to Tools\Options\Text Editor\C#\Formatting and uncheck Automatically format pasted code.