C++
bool isNull();
Description
Returns true if the AcAxObjectRef instance contains no object reference; otherwise returns false.
- Customization and Administration Guides
- DXF Reference
- AutoLISP and DCL
- ActiveX and VBA
- ObjectARX and Managed .NET
- ObjectARX: Developer's Guide
- ObjectARX: Reference Guide
- What's New
- Migration Guide
- ObjectARX Reference Guide
- AcAp Classes
- AcAx Classes (WIN)
- AcBr Classes
- AcCm Classes
- AcDb Classes
- AcEd Classes (WIN)
- AcFd and CAcFdUi Classes
- AcGe Classes
- AcGi Classes
- AcGs Classes (WIN)
- AcLy Classes
- AcPl Classes (WIN)
- AcPublish Classes (WIN)
- AcRx Classes
- AcTransaction Classes
- AcTrayItem Classes (WIN)
- MFC Extension Classes (WIN)
- DWF Metadata Manager Classes (WIN)
- Property Palette Classes and Interfaces (WIN)
- Global Enums
- Global Functions
- Miscellaneous Classes
- Macros
- Structs
- Types and Unions
- DesignCenter Interfaces (WIN)
- eTransmit Interfaces (WIN)
- CAD Standards Interfaces (WIN)
- Tool Palette Classes and Interfaces (WIN)
- Additional Information
- ObjectARX: Managed .NET Developer's Guide
- ObjectARX: Managed .NET Reference Guide
- ObjectARX: Interoperability Guide
- ObjectARX: Migration Guide
- ObjectARX: Release Notes
- JavaScript
- AutoCAD Core Console