View |
Sets the underlay base and underlay top to the specified levels.
Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 25.3.0.0 (25.3.0.0)

Parameters
- baseLevelId ElementId
- The element id of a level in the project or InvalidElementId. If InvalidElementId, then the underlay base level is not set and no elements will be displayed as underlay.
- topLevelId ElementId
- The element id of a level in the project or InvalidElementId. If InvalidElementId, then the underlay range is unbounded.

Exception | Condition |
---|---|
ArgumentException | The ElementId baseLevelId does not correspond to a Level in the project. -or- The ElementId topLevelId does not correspond to a Level in the project. -or- The elevation of level topLevelId must be greater than the elevation of level baseLevelId. |
ArgumentNullException | A non-optional argument was null |
