C++
virtual Adesk::ULongPtr viewportId() const = 0;
Description
Returns the AcGi viewport ID. This is an AcGi-specific ID that has no relation to the AutoCAD CVPORT system variable. This ID is used by the AcGiViewportDraw::isValidId() function to determine if a viewport is still valid.
The ID returned by this function is unique for every viewport in AutoCAD (including Paper Space AcDbViewports and tiled view windows when TILEMODE == 1) much the way a handle is for an entity.