Proposal: GenericHost support for Add-Migration

[Reza-Noei]

Previously I have used different patterns to make Add-Migration works. Design-Time factory works fine for me in WinUI3.

but later on we added GenericHost to our WinUI3 app.

I've tried to remove these Design-Time factories and follow Application Service pattern. because it works with my configurations while Design-Time factory doesn't. So I don't needed to hard-code my ConnectionStrings in the code base.

But I'm getting this error when I'm running Add-Migration:

An error occurred while accessing the Microsoft.Extensions.Hosting services. Continuing
without the application service provider. Error: Unable to load DLL 'Microsoft.ui.xaml.dll'
or one of its dependencies: The specified module could not be found. (0x8007007E)
Unable to create an object of type 'BusinessDomainContext'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728

here is my command:

Add-Migration InitialCreate2 -Context BusinessDomainContext -OutputDir Migrations\BusinessDomain

I don't understand the source of this problem.

At the next step I've tried to add below config to my *.csproj. Error got solved:

<WindowsAppSDKSelfContained>true</WindowsAppSDKSelfContained>

But Nothing happened after that.
Using --verbose I've got this logs:

 Using project directory 'D:\...' Remaining arguments: .
 Finding DbContext classes...
 Finding IDesignTimeDbContextFactory implementations...
 Finding application service provider in assembly 'DesktopApplication'...
 Finding Microsoft.Extensions.Hosting service provider...
 Using environment 'Development'.

At the next step I have tried to DISABLE_XAML_GENERATED_MAIN by updating *.csproj file.

	<DefineConstants>DISABLE_XAML_GENERATED_MAIN</DefineConstants>

I have added new Program.cs file. with this content:

public static void Main(string[] args) 
    => CreateHostBuilder(args).Build().Run();

// EF Core uses this method at design time to access the DbContext
public static IHostBuilder CreateHostBuilder(string[] args)
=> Host.CreateDefaultBuilder(args).ConfigureServices(services=>
{
    services.AddDbContext<BusinessDomainContext>(options =>
    {
        options.UseSqlServer("Data Source=(localdb)\\MSSQLLocalDB;Initial Catalog=aa.BusinessDomain;Integrated Security=True;MultipleActiveResultSets=true;");
    });
});

For me, I looks terrific, But it works.
There is an open Issue for this which is open from 2022. and the thing I've done looks bad. I think Microsoft should release WinUI3 in compatible form. I should not re-invent things to getting it to work.

[soroshsabz]

ITNOA

I think it is Bug and not feature

/bug

[soroshsabz]

cc @bpulliam