C# Wrapper Classes

In addition to the direct bindings to HOOPS Exchange binaries, the C# API provides high-level classes called wrappers.

Wrapper classes encapsulate both the entity handle and a local copy of its data structure, providing a C#-idiomatic interface to HOOPS Exchange. For example, a model file entity managed by an A3DAsmModelFile/A3DAsmModelFileData set has a wrapper class called A3DAsmModelFileWrapper.

These classes offer features such as constructors, resource management, inheritance, and properties. However, the current version of the C# API limits wrappers to short-lived, read-only entities. For other functionalities, you can still fallback to call bindings.

Comparison with Struct Bindings

Wrapper classes enhance the struct bindings by providing:

• Simplified struct initialization
• Automatic data loading
• Memory management
• C# properties for seamless access
• Methods for entity creation and editing

Struct Initialization

Wrapper classes provide default constructors that initialize internal data structures using API.Initialize().

C# (Wrapper Class)

var export_params = new A3DRWParamsExportXMLDataWrapper();

C# (Binding Layer)

A3DRWParamsExportXMLData export_params;
API.Initialize(out export_params);

C

A3DRWParamsExportXMLData export_params;
A3D_INITIALIZE_DATA(A3DRWParamsExportXMLData, export_params);

Data Load

When instantiated with an entity handle, wrapper classes automatically load entity data into the internal structure:

C# (Wrapper Class)

var model_file = new A3DAsmModelFileWrapper(model_file_handle);

C# (Binding Layer)

A3DAsmModelFileData model_file_data;
API.Initialize(out model_file_data);

API.A3DAsmModelFileGet(model_file_handle, ref model_file_data);

C

A3DAsmModelFileData model_file_data;
A3D_INITIALIZE_DATA(A3DAsmModelFileData, model_file_data);

A3DAsmModelFileGet(model_file_handle, &model_file_data);

Memory Management

Wrapper classes implement the IDisposable interface to manage unmanaged resources. To free resources, call Dispose() explicitly:

C# (Wrapper Class)

var model_file = new A3DAsmModelFileWrapper(model_file_handle);

// Use the model file
model_file.Dispose();

C# (Binding Layer)

A3DAsmModelFileData model_file_data;
API.Initialize(out model_file_data);

API.A3DAsmModelFileGet(model_file_handle, ref model_file_data);

// Use the model file
API.A3DAsmModelFileGet(IntPtr.Zero, ref model_file_data);

C

A3DAsmModelFileData model_file_data;
A3D_INITIALIZE_DATA(A3DAsmModelFileData, model_file_data);

A3DAsmModelFileGet(model_file_handle, &model_file_data);

// Use the model file
A3DAsmModelFileGet(0, &model_file_data);

Alternatively, use the using statement to ensure automatic disposal:

using (var model_file = new A3DAsmModelFileWrapper(model_file_handle))
{
    // Use the model file
}

For details, see Using objects that implement IDisposable (MSDN).

Properties

Wrapper classes expose fields of data structures as C# Properties:

C# (Wrapper Class)

var model_file = new A3DAsmModelFileWrapper(model_file_handle);

bool unit_from_cad = model_file.m_bUnitFromCAD; // Property get

C# (Binding Layer)

A3DAsmModelFileData model_file_data;
API.Initialize(out model_file_data);

API.A3DAsmModelFileGet(model_file_handle, ref model_file_data);

bool unit_from_cad = model_file_data.m_bUnitFromCAD;

C

A3DAsmModelFileData model_file_data;
A3D_INITIALIZE_DATA(A3DAsmModelFileData, model_file_data);

A3DAsmModelFileGet(model_file_handle, &model_file_data);

A3DBool unit_from_cad = model_file_data.m_bUnitFromCAD;

Properties include both get and set accessors. Array properties are automatically converted to and from unmanaged C-style arrays using C# Array Wrapper. The example below shows how to retrieve a list of child product occurrences as an IntPtr[]:

C# (Wrapper Class)

var product_occurrence = new A3DAsmProductOccurrence(product_occurrence_handle);

IntPtr[] children_handles = product_occurrence.m_ppPOccurrences;

C# (Binding Layer)

A3DAsmProductOccurrenceData product_occurrence_data;
API.Initialize(out product_occurrence_data);

API.A3DAsmModelFileGet(product_occurrence_handle, ref product_occurrence_data);

IntPtr[] children_handles = ArrayWrapper.ReadIntPtrArray(
    product_occurrence_data.m_ppPOccurrences,
    product_occurrence_data.m_uiPOccurrencesSize
);

Entity Creation

Wrapper classes provide a Create() method to encapsulate the entity creation process:

C# (Wrapper Class)

var model_file = new A3DAsmModelFileWrapper();

model_file.Create();

C# (Binding Layer)

A3DAsmModelFileData model_file_data;
API.Initialize(out model_file_data);

IntPtr model_file_handle = IntPtr.Zero;
API.A3DAsmModelFileCreate(ref model_file_data, out model_file_handle);

C

A3DAsmModelFileData model_file_data;
A3D_INITIALIZE_DATA(A3DAsmModelFileData, model_file_data);

A3DAsmModelFile model_file_handle = 0;
A3DAsmModelFileCreate(&model_file_data, &model_file_handle);

Entity Edition

If an entity supports editing, wrapper classes provide an Edit() method:

C# (Wrapper Class)

// ...

model_file.Edit();

C# (Binding Layer)

// ...

API.A3DAsmModelFileEdit(ref model_file_data, model_file_handle);

C

// ...

A3DAsmModelFileEdit(&model_file_data, model_file_handle);