TL;DR; Read only bold ones you fat.
I bet, you didn't know you can do like this.
 A purpose to open a WPF project
 JetBrains Rider (No Tonny, Visual Studio is bad for your health.)
 Open Rider ♥
 Click New Solution
.Net Core (But sir I don't want dotnet core, I want my project in normal regular
NetFramework X.Y bla bla bla...) Just select the fucking
DotNet Core Desktop Application I will get there alright.
Create .git and thank me now.
 Finally, hit the
Create button (Do not forget to give a name to your $0.0F project.)
<TargetFrameworks> for supporting more customer and earn more money and do more writing of course.
 For now, you should be able to Build and Run your project and see the worthless Window. Well done!
You might want to add multiple projects for your
BLL for your garbage code.
To understand the reasion you can create a regular project and compare
 When you are create a class library on Rider, it does not automatically adds
<UseWPF>true</UseWPF> like it adds on
DesktopApplication so add it.
 As last step before write your own code create a class named
AssemblyInfo.cs with filled with code:
using System.Windows; [assembly: ThemeInfo( ResourceDictionaryLocation.None, ResourceDictionaryLocation.SourceAssembly )]
Now you are good to go.
If you do not do step  or  or  Rider cannot build and complain that you suck and do not deserve to use
JetBrains Rider so you should go back to use
Visual Studio like every regular boring developers do. (When Rider fixes this problem, this paragraph will destroy itself.).