Revit Selection Filter

Revit Selection Filter

Selection.PickObject takes an ISelectionFilter that constrains what the user may pick. SelectionConfiguration (from Nice3point.Revit.Toolkit) builds that filter from two lambdas; no hand-rolled class is needed. It drives an interactive pick and needs the Revit UI.

When to use

• Restricting an interactive pick to a category, type, or geometry kind.

When not to use

• Constraining a headless API callback such as family load or duplicate-type options — use a Toolkit option handler like FamilyLoadOptions.

Workflow

Step 1: Configure the allowed elements and references

Allow.Element gates which elements are pickable; Allow.Reference gates which references (faces, edges, points). Set either or both — each returns the configuration and they chain — then pass configuration.Filter to the pick call.

var configuration = new SelectionConfiguration()
    .Allow.Element(element => element.Category.Id.IsCategory(BuiltInCategory.OST_Walls))
    .Allow.Reference((reference, position) => false);

var picked = uiDocument.Selection.PickObject(ObjectType.Element, configuration.Filter);

Step 2: Verify

Run the command and confirm only the intended elements or references highlight and accept a pick.

Validation

• The filter uses SelectionConfiguration, not a hand-rolled ISelectionFilter.
• Allow.Element/Allow.Reference express the rule with a lambda, not a new class.

Common Pitfalls