This section covers changes to the AutoCAD Civil 3D .NET API for the 2018 release.
Two classes have been added for folder management in Prospector.
| Class Name | API Name | Description |
| FolderUtil | GetNonAlignmentRootFolder() | Gets the root folder ObjectId for a non-alignment object type. Supported object types are surface, pipe network, pressure network, corridor, view frame group, and intersection. |
| GetAlignmentRootFolder() | Gets the root folder ObjectId for the specified alignment type | |
| FolderNode | GetFolder() | Gets the child folder ObjectId by name or path |
| CreateFolder() | Creates a child folder with the input folder name and returns the created child folder ObjectId | |
| GetPath() | Gets a string containing the path relative to the root folder | |
| GetParent() | Gets the parent folder ObjectId | |
| GetSubFolders() | Gets the ObjectIdCollection of subfolders | |
| RenameFolder() | Renames the folder | |
| DeleteFolder() | Deletes the folder | |
| AddEntity() | Adds the entity specified by entityId to the folder |
| Class Name | API Name | Description |
| Entity | FingerPrint | Gets or sets the FingerPrint of the entity |
| ComputeFingerPrint() | Computes the FingerPrint of the entity | |
| SettingsCmdAssemblyInsertion | CorridorAlongCurveOption | Gets the corridor along alignment curve option |
| MODAlongCurves | Gets the corridor station placement frequency by mid-ordinate of the alignment curvature | |
| CorridorAlongOffsetTargetCurvesOption | Gets the corridor along offset alignment curve option | |
| FrequencyAlongOffsetTargetCurves | Gets the corridor station placement frequency along offset target curves | |
| MODAlongOffsetTargetCurves | Gets the corridor station placement frequency along offset target curves | |
| AdditionalAppliedAssemblyInfo | CorridorAlongCurvesOption | Gets or sets the value to specify the assembly insertion option along the alignment curve |
| MODAlongCurves | Gets or sets the value to specify the alignment curve mid-ordinate value for assembly insertion | |
| TargetCurveOption | Gets or sets the value to specify the assembly insertion option along the offset target curve | |
| MODAlongTargetCurves | Gets or sets the value to specify the offset target curve mid-ordinate value for assembly insertion | |
| FrequencyAlongTargetCurves | Gets or sets the value to specify the assembly insertion frequency along the curve portion of the offset target | |
| BaselineCollection | default[System::Guid] | Gets a baseline by GUID |
| AddGUIDBaseline() | Adds a baseline with the given baseline name, alignment, profile, and GUID | |
| GridSurface | SampleElevations() | Gets the sample points of a grid surface along the line specified by inputting two points |
| TinSurface | SampleElevations() | Gets the sample points of a TIN surface along the line specified by inputting two points |
If you are using the COM API, you need to update the object version to 12.0 (from 11.0 used in AutoCAD Civil 3D 2017). The objects and interfaces exposed have remained the same, but you should reference the new libraries, which are installed by default to: C:\Program Files\Common Files\Autodesk Shared\Civil Engineering 120.