public const string IFCEngineDLL = @"IFCEngine.dll";

[DllImport(IFCEngineDLL, EntryPoint = "internalGetInstanceFromP21Line")]
public static extern Int64 internalGetInstanceFromP21Line(Int64 model, Int64 P21Line);    

Property model

Size: 64 bit / 8 byte (value)
Handle of the model containing the IFC file, this handle is needed in many other calls and given when the model is created.

Property P21Line

Size: 64 bit / 8 byte (value)
SPFF address line, i.e. 31313 in line '#31313 = IFCWALLSTANDARDCASE(...);'.


Here you can find code snippits that show how the API call internalGetInstanceFromP21Line can be used.