PIBIO_ENGINE_CREATE_ENROLLMENT_FN回调函数 (winbio_adapter.h)

由 Windows 生物识别框架调用以初始化生物识别单元管道中的注册对象。

语法

PIBIO_ENGINE_CREATE_ENROLLMENT_FN PibioEngineCreateEnrollmentFn;

HRESULT PibioEngineCreateEnrollmentFn(
  [in, out] PWINBIO_PIPELINE Pipeline
)
{...}

参数

[in, out] Pipeline

指向与执行操作的生物识别单元关联的 WINBIO_PIPELINE 结构的指针。

返回值

如果函数成功，则返回S_OK。 如果函数失败，它必须返回以下 HRESULT 值之一来指示错误。

返回代码	说明
E_POINTER	Pipeline 参数不能为 NULL。
E_OUTOFMEMORY	内存不足，无法完成此操作。

注解

EngineAdapterCommitEnrollment 标记注册事务的开始。 如果此函数成功，Windows 生物识别框架将调用 EngineAdapterUpdateEnrollment ，以将一个或多个功能集添加到注册对象。 然后，框架调用 EngineAdapterCommitEnrollment 或 EngineAdapterDiscardEnrollment 来完成事务。

示例

以下伪代码演示了此函数的一种可能实现。 该示例不编译。 必须根据自己的目的调整它。

//////////////////////////////////////////////////////////////////////////////////////////
//
// EngineAdapterCreateEnrollment
//
// Purpose:
//      Initialize the enrollment object in the biometric unit pipeline.
//
// Parameters:
//      Pipeline    - Pointer to a WINBIO_PIPELINE structure associated 
//                    with the biometric unit performing the operation
//
static HRESULT
WINAPI
EngineAdapterCreateEnrollment(
    __inout PWINBIO_PIPELINE Pipeline
    )
{
    HRESULT hr = S_OK;

    // Verify that the Pipeline parameter is not NULL.
    if (!ARGUMENT_PRESENT(Pipeline))
    {
        hr = E_POINTER;
        goto cleanup;
    }

    // Retrieve the context from the pipeline.
    PWINBIO_ENGINE_CONTEXT context = 
           (PWINBIO_ENGINE_CONTEXT)Pipeline->EngineContext;

    // Return if an enrollment is already in progress. This example assumes that 
    // your engine adapter context contains an enrollment object.
    if (context->Enrollment.InProgress == TRUE)
    {
        hr = WINBIO_E_INVALID_DEVICE_STATE;
        goto cleanup;
    }

    // Call a custom function (_AdapterCreateEnrollmentTemplate) to create a 
    // new enrollment template and attach it to the engine adapter context.
    hr = _AdapterCreateEnrollmentTemplate( 
            context, 
            &context->Enrollment
            );
    if (FAILED(hr))
    {
        goto cleanup;
    }

    // Initialize any Enrollment data members not initialized by  the 
    // _AdapterCreateEnrollmentTemplate function. This example assumes that
    // your enrollment object contains at a minimum a field that specifies 
    // the number of biometric samples and another that specifies whether a
    // new enrollment is in progress.
    context->Enrollment.SampleCount = 0;
    context->Enrollment.InProgress = TRUE;

cleanup:

    return hr;
}

要求

要求	值
最低受支持的客户端	Windows 7 [仅限桌面应用]
最低受支持的服务器	Windows Server 2008 R2 [仅限桌面应用]
目标平台	Windows
标头	winbio_adapter.h (包括 Winbio_adapter.h)

另请参阅

插件函数