M

ViewPlan.SetUnderlayRange

Description:
Sets the underlay base and underlay top to the specified levels.

public void SetUnderlayRange(
	ElementId baseLevelId,
	ElementId topLevelId
)

Public Sub SetUnderlayRange ( _
	baseLevelId As ElementId, _
	topLevelId As ElementId _
)

public:
void SetUnderlayRange(
	ElementId^ baseLevelId, 
	ElementId^ topLevelId
)

Autodesk.Revit.DB.ElementId

baseLevelId

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.
Autodesk.Revit.DB.ElementId

topLevelId

The element id of a level in the project or InvalidElementId. If InvalidElementId, then the underlay range is unbounded.

private void ViewUnderlay(ViewPlan planView, ElementId topLevelId, ElementId baseLevelId)
{
    if (planView.GetUnderlayOrientation() == UnderlayOrientation.LookingDown)
    {
        if (planView.GetUnderlayTopLevel() != topLevelId)
        {
            planView.SetUnderlayRange(baseLevelId, topLevelId);
        }

        planView.SetUnderlayOrientation(UnderlayOrientation.LookingUp);
    }
}

Private Sub ViewUnderlay(planView As ViewPlan, topLevelId As ElementId, baseLevelId As ElementId)
    If planView.GetUnderlayOrientation() = UnderlayOrientation.LookingDown Then
        If planView.GetUnderlayTopLevel() <> topLevelId Then
            planView.SetUnderlayRange(baseLevelId, topLevelId)
        End If

        planView.SetUnderlayOrientation(UnderlayOrientation.LookingUp)
    End If
End Sub

Autodesk.Revit.Exceptions.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.
Autodesk.Revit.Exceptions.ArgumentNullException

A non-optional argument was NULL