I created a .Net Standard Library for using SQLite.The target framework of .net Standard Library is .net standard 2.0.
After I add it to a UWP Project, the visual studio reports an error as below:

It seems I do not reference the .net standard package so that I installed it to the UWP project in nuget:

However, the problem still here.
In addition,here is the targeting of the UWP project:
And I installed the .net core v2.2.0-preview SDK&Runtime before.
I don't know what's the problem and it seems not only this .Net Standard Library runs in UWP reports this error but also all the .Net Standard Library runs in UWP reports this error.
Would you please help me?Thank you.