WbioQueryEngineInterface function (winbio_adapter.h)

Article
02/22/2024

Retrieves a pointer to the WINBIO_ENGINE_INTERFACE structure for the engine adapter.

Syntax

HRESULT WbioQueryEngineInterface(
  [out] PWINBIO_ENGINE_INTERFACE *EngineInterface
);

Parameters

[out] EngineInterface

Address of a variable that receives a pointer to the WINBIO_ENGINE_INTERFACE structure.

Return value

If the function succeeds, it returns S_OK. If the function fails, it must return one of the following HRESULT values to indicate the error.

Return code	Description
E_POINTER	The EngineInterface parameter cannot be NULL.

Remarks

The Windows Biometric Framework calls this function after loading an engine adapter DLL into memory. Every engine adapter DLL must therefore implement and export the WbioQueryEngineInterface function. The function name is case-sensitive, and its spelling and signature must exactly match that provided in the Syntax section.

To be visible to the Windows Biometric Framework, the WbioQueryEngineInterface function must be named in the EXPORTS section of the export definition linker command file for the DLL.

Examples

The following pseudocode shows one possible implementation of this function.

HRESULT
WINAPI
WbioQueryEngineInterface(
    __out PWINBIO_ENGINE_INTERFACE *EngineInterface)
{
    // g_EngineInterface is a global variable.
    *EngineInterface = &g_EngineInterface;
    return S_OK;
}

Requirements

Requirement	Value
Minimum supported client	Windows 7 [desktop apps only]
Minimum supported server	Windows Server 2008 R2 [desktop apps only]
Target Platform	Windows
Header	winbio_adapter.h (include Winbio_adapter.h)

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