Make the DemoConsole application multi-targeted to both .NET and .NET Framework

[Olina-Zhang]

.NET version

10.0.100-alpha.1.25072.10

Did it work in .NET Framework?

Not tested/verified

Did it work in any of the earlier releases of .NET Core or .NET 5+?

Not an issue, need to modify DemoConsole application with multi-targeted

Issue description

Make the DemoConsole application in Winforms repo multi-targeted to both .NET and .NET Framework so that we can validate where we've got regressions from NetFX

[ricardobossan]

@Tanya-Solyanik @LeafShi1 @Epica3055

I created PR #12885 to show my current approach for making DemoConsole multi-targeted.

However, the build fails with the following errors:

PS C:\Users\v-rbossan\winforms> .\Restore.cmd;.\build.cmd
Variable NativeToolsOnMachine detected, enabling native tool path promotion...
Processing C:\Users\v-rbossan\winforms\global.json
  C:\.tools\.nuget\packages\microsoft.dotnet.arcade.sdk\10.0.0-beta.25074.4\tools\Tools.proj             Restore (0.7s)
  Runtime toolset 'dotnet/x64 v10.0.0-preview.2.25104.8' already installed.                                      (1.3s)
Restauração concluída (1.3s)
  Winforms falhou com 4 erro(s) (0.4s)
    C:\Users\v-rbossan\winforms\src\System.Windows.Forms\tests\IntegrationTests\DesignSurface\DesignSurfaceExt\DesignSurfaceExt.csproj : error NU1201: O projeto System.Design não é compatível com net462 (.NETFramework,Version=v4.6.2). O projeto System.Design dá suporte a: net10.0 (.NETCoreApp,Version=v10.0)
    C:\Users\v-rbossan\winforms\src\System.Windows.Forms\tests\IntegrationTests\DesignSurface\DesignSurfaceExt\DesignSurfaceExt.csproj : error NU1201: O projeto System.Drawing.Design não é compatível com net462 (.NETFramework,Version=v4.6.2). O projeto System.Drawing.Design dá suporte a: net10.0 (.NETCoreApp,Version=v10.0)
    C:\Users\v-rbossan\winforms\src\System.Windows.Forms\tests\IntegrationTests\DesignSurface\DesignSurfaceExt\DesignSurfaceExt.csproj : error NU1201: O projeto System.Windows.Forms.Design não é compatível com net462 (.NETFramework,Version=v4.6.2). O projeto System.Windows.Forms.Design dá suporte a: net10.0 (.NETCoreApp,Version=v10.0)
    C:\Users\v-rbossan\winforms\src\System.Windows.Forms\tests\IntegrationTests\DesignSurface\DesignSurfaceExt\DesignSurfaceExt.csproj : error NU1201: O projeto System.Windows.Forms não é compatível com net462 (.NETFramework,Version=v4.6.2). O projeto System.Windows.Forms dá suporte a: net10.0 (.NETCoreApp,Version=v10.0)

Construir falhou com 4 erro(s) em 3.7s
Build failed with exit code 1. Check errors above.
Variable NativeToolsOnMachine detected, enabling native tool path promotion...
Processing C:\Users\v-rbossan\winforms\global.json
  C:\.tools\.nuget\packages\microsoft.dotnet.arcade.sdk\10.0.0-beta.25074.4\tools\Tools.proj             Restore (0.7s)
  Runtime toolset 'dotnet/x64 v10.0.0-preview.2.25104.8' already installed.                                      (1.3s)
Restauração concluída (1.3s)
  Winforms falhou com 4 erro(s) (0.2s)
    C:\Users\v-rbossan\winforms\src\System.Windows.Forms\tests\IntegrationTests\DesignSurface\DesignSurfaceExt\DesignSurfaceExt.csproj : error NU1201: O projeto System.Design não é compatível com net462 (.NETFramework,Version=v4.6.2). O projeto System.Design dá suporte a: net10.0 (.NETCoreApp,Version=v10.0)
    C:\Users\v-rbossan\winforms\src\System.Windows.Forms\tests\IntegrationTests\DesignSurface\DesignSurfaceExt\DesignSurfaceExt.csproj : error NU1201: O projeto System.Drawing.Design não é compatível com net462 (.NETFramework,Version=v4.6.2). O projeto System.Drawing.Design dá suporte a: net10.0 (.NETCoreApp,Version=v10.0)
    C:\Users\v-rbossan\winforms\src\System.Windows.Forms\tests\IntegrationTests\DesignSurface\DesignSurfaceExt\DesignSurfaceExt.csproj : error NU1201: O projeto System.Windows.Forms.Design não é compatível com net462 (.NETFramework,Version=v4.6.2). O projeto System.Windows.Forms.Design dá suporte a: net10.0 (.NETCoreApp,Version=v10.0)
    C:\Users\v-rbossan\winforms\src\System.Windows.Forms\tests\IntegrationTests\DesignSurface\DesignSurfaceExt\DesignSurfaceExt.csproj : error NU1201: O projeto System.Windows.Forms não é compatível com net462 (.NETFramework,Version=v4.6.2). O projeto System.Windows.Forms dá suporte a: net10.0 (.NETCoreApp,Version=v10.0)

Construir falhou com 4 erro(s) em 4.8s
Build failed with exit code 1. Check errors above.

It looks like some dependencies aren't resolving correctly for net462. I’ve checked previous PRs related to multi-targeting but haven’t found a clear solution.

Is there an existing approach for handling this, or should we explore alternative strategies?

[Tanya-Solyanik]

It does not have to be net462, it could be 4.8.1 to test against the latest. Does the version make a difference?

[LeafShi1]

It does not have to be net462, it could be 4.8.1 to test against the latest. Does the version make a difference?

Using net481 will also fail to build, because other projects referenced in project Demo are based on net10, such as System.Windows.Forms.Design.csproj.

If it is not referenced when TargetFramework=net481, Error1 will appear, and if it is referenced, Error2 will appear
Error1：

Error2: