Thanks. With SelectionSet I know how to create filter with a SelectionFilter. I want to find method for GetEntity. I found it in sample from Mr Kean WalmSley. We use PromptEntityOptions.AddAllowedClass(). But it's only filter for class, not all properties like color, linetype, layer...
See detail at here >>>>>>> this link<<<<<<<<<
GetEntity will return a PromptEntityResult which contains the ObjectID of the entity selected. You can then open it for read and examine the ent's properties. If it doesn't meet your criteria, you can prompt them to select again.
I got all excited at being able to define a simple entity filter like which was possible with (ssget) in AutoLisp. I started using his approach but then quickly discovered that entities like "3DFACE" don't appear to have Type Classes defined in .NET.
With regard to the original query of this thread (granted, the thread is a few years old), a method of advanced filtering for an individual entity was discussed in this thread. If the OP is still around, the concept may be of some interest.