Update template to use TFM-based sources; enabled latest lang features

[RussKie]

(cherry picked from commit ee658c4 / #5547)

Fixes #5074

Proposed changes

• Enable implicit global usigns
• Enable file-based namespaces

Regression?

• No, new functionality

Risk

• Minimal

Test methodology

Manually create various apps and verify the expected content

dotnet new -i C:\Development\winforms\pkg\Microsoft.Dotnet.WinForms.ProjectTemplates\content\WinFormsApplication-CSharp
cd .. && md template1 && cd template1 && dotnet new winforms  && code . 
cd .. && md template2 && cd template2 && dotnet new winforms -f net6.0 && code . 
cd .. && md template3 && cd template3 && dotnet new winforms -f net5.0 && code . 
cd .. && md template4 && cd template4 && dotnet new winforms -f netcoreapp3.1 && code . 

dotnet new -i C:\Development\winforms\pkg\Microsoft.Dotnet.WinForms.ProjectTemplates\content\WinFormsControlLibrary-CSharp
cd .. && md template12 && cd template12 && dotnet new winformscontrollib && code . 
cd .. && md template22 && cd template22 && dotnet new winformscontrollib -f net6.0 && code . 
cd .. && md template32 && cd template32 && dotnet new winformscontrollib -f net5.0 && code . 
cd .. && md template42 && cd template42 && dotnet new winformscontrollib -f netcoreapp3.1 && code . 

dotnet new -i C:\Development\dotnet-winforms\pkg\Microsoft.Dotnet.WinForms.ProjectTemplates\content\WinFormsLibrary-CSharp
cd .. && md template01 && cd template01 && dotnet new winformslib  && code . 
cd .. && md template21 && cd template21 && dotnet new winformslib -f net6.0 && code . 
cd .. && md template31 && cd template31 && dotnet new winformslib -f net5.0 && code . 
cd .. && md template41 && cd template41 && dotnet new winformslib -f netcoreapp3.1 && code .

Microsoft Reviewers: Open in CodeFlow

[RussKie]

@Pilchie seeking approval to take into RC2.

@DamianEdwards this essentially wraps our templating story.

[Pilchie]

Need @DamianEdwards' signoff here.

[Pilchie]

I don't think we want this to show up in the project file.

[Pilchie]

Also, has a lower case l

[RussKie]

This is a command line argument and aligns with this:

winforms/pkg/Microsoft.Dotnet.WinForms.ProjectTemplates/content/WinFormsApplication-CSharp/.template.config/template.json

Lines 52 to 59 in 07f6de3

	"langVersion": {
	"type": "parameter",
	"datatype": "text",
	"description": "Sets langVersion in the created project file",
	"defaultValue": "",
	"replaces": "$(ProjectLanguageVersion)",
	"displayName": "Language Version"
	},

The command line args are case sensitive:

There's an open tracking issue for this dotnet/templating#3237

[Pilchie]

I thought the decision was not to use these in the templates, and have the VS option apply formatting to decide which form to use?

[DamianEdwards]

For templates that aren't splitting their identity based on TFM and accept a language version parameter (like these), yes, I believe that was the decision.

[RussKie]

These changes were suggested to us by the dotnet/templating team and aligns with changes made in that repo (e.g. dotnet/templating#3454).

[DamianEdwards]

@Pilchie @KathleenDollard was it that item templates would keep using block-scoped namespace declarations, but the project templates that had an option to change the language version would selectively apply file-scoped when the version was high-enough (or not specified) perhaps?

[Pilchie]

@davidwengier - do you know what the conclusion was for templates and file scoped namespaces?

[davidwengier]

@davidwengier - do you know what the conclusion was for templates and file scoped namespaces?

In current dogfood builds, Roslyn will reformat namespaces (and other things) for any new file that is added, based on a users preferences.

[RussKie]

So any further objections?

[DamianEdwards]

@RussKie no I think you're good to go.