使用Visual Studio 2019 Preview for Mac从带内置程序集的``内置''程序集替换类引用

Question

Background: I'm currently trying to use EF6 to connect to a MySQL database and am searching for a resolution to an error message about a type not being able to be loaded from an assembly . I believe I've found a possible solution, using an out-of-band release of a different assembly that includes the class , but that solution has yielded yet another question that seems to be distinct enough from the first to be its own question (even though answering one question may answer both).

Question: How can I include an out-of-band assembly using Visual Studio 2019 Preview for Mac in a way that lets me use a specific class from the assembly? I'd like to use the 3.0 preview release of System.Component.Annotations to get at the AssociatedMetadataTypeTypeDescriptionProvider class required by EF. When I try to follow the instructions for adding an OOB assembly and rebuild my project, an exception gets thrown indicating that the old version of a different assembly that seems to also include that class.

Package Console Output:

Successfully installed 'System.ComponentModel.Annotations 4.6.0-preview.18571.3' to Ef2MySql

Exception:

TypeLoadException: Could not load type 'System.ComponentModel.DataAnnotations.AssociatedMetadataTypeTypeDescriptionProvider' from assembly 'System.ComponentModel.DataAnnotations, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.

edit: I just checked that AssociatedMetadataTypeTypeDescriptionProvider is in the NuGet package by running nuget install System.ComponentModel.Annotations -Version 4.6.0-preview.19073.11 in an unrelated, empty directory and them opening System.ComponentModel.Annotations.4.6.0-preview.19073.11/lib/net461/System.ComponentModel.Annotations.dll with VS. However, it's not in all of the DLLs in the NuGet package. Just the one in net461 .

further edit: However, adding the assembly that I verified has the class as an .NET assembly (rather than using NuGet in VS) still does not resolve the error.

Answer 1

## Consider using sqlite instead ##

Microsoft RazorPagesMovie tutorial using sqlite instead of mysql in Visual Studio 2019 for Mac:

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(Try to modify it to include your issue, and hopefully you may learn from it enough to help you resolve your issues with mysql)

1. Follow Tutorial: Get started with Razor Pages in ASP.NET Core
2. And the second part: Add a model to a Razor Pages app in ASP.NET Core