Upgrade WinForms Apps from .NET Core 3.0 to 3.1
I upgraded a WinForms App to .NET Core 3.1 these days. It's an open-source on-screen ruler created by Jeff Key in 2004, the original code was for .NET Framework 2.0, I've already upgraded it to .NET Core 3.0 in September this year, it was very smooth without any code change. But this time, .NET Core 3.1 does require some code changes. The project is on my GitHub: https://github.com/EdiWang/ …