Awhile ago, I needed a Spy++ like application for some .NET UI debugging. I found an old MSDN article with a sample that does things similarly, But that stopped working in n
For winforms applications you still can use Spy++ as usual.
For WPF applications take a look to this link . It talks about a tool called snoop. With this tool you can look into a WPF application.
As a side note, I haven't been able to make it work though