File IO API Calls
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Geometry Kernel related API Calls
Deprecated API Calls (GENERIC)
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Deprecated API Calls (GEOMETRY)

engiGetAttrOptionalBN

This call can be used to check if an attribute is optional. Technically engiGetAttrOptionalBN will transform into the following call

    engiGetAttrOptional(
            sdaiGetAttrDefinition(
                    entity,
                    attributeName
                )
        );

Syntax

C++ 32 bit
C++ 64 bit
C# 32 bit
C# 64 bit
public const string ifcenginedll = @"ifcengine.dll";

[DllImport(IFCEngineDLL, EntryPoint = "engiGetAttrOptionalBN")]
public static extern Int64 engiGetAttrOptionalBN(int_t entity, string attributeName);

[DllImport(IFCEngineDLL, EntryPoint = "engiGetAttrOptionalBN")]
public static extern Int64 engiGetAttrOptionalBN(int_t entity, byte[] attributeName);

Property entity

Size: 64 bit / 8 byte (value)
...

Property attributeName

Size: 64 bit / 8 byte (reference)
...