WinBioDeleteTemplate function (winbio.h)
Deletes a biometric template from the template store. Starting with Windows 10, build 1607, this function is available to use with a mobile image.
Syntax
HRESULT WinBioDeleteTemplate(
[in] WINBIO_SESSION_HANDLE SessionHandle,
[in] WINBIO_UNIT_ID UnitId,
[in] WINBIO_IDENTITY *Identity,
[in] WINBIO_BIOMETRIC_SUBTYPE SubFactor
);
Parameters
[in] SessionHandle
A WINBIO_SESSION_HANDLE value that identifies an open biometric session. Open a synchronous session handle by calling WinBioOpenSession. Open an asynchronous session handle by calling WinBioAsyncOpenSession.
[in] UnitId
A WINBIO_UNIT_ID value that identifies the biometric unit where the template is located.
[in] Identity
Pointer to a WINBIO_IDENTITY structure that contains the GUID or SID of the template to be deleted. If the Type member of the WINBIO_IDENTITY structure is WINBIO_ID_TYPE_WILDCARD, templates matching the SubFactor parameter will be deleted for all identities. Only administrators can perform wildcard identity deletion.
[in] SubFactor
A WINBIO_BIOMETRIC_SUBTYPE value that provides additional information about the template to be deleted. If you specify WINBIO_SUBTYPE_ANY, all templates for the biometric unit specified by the UnitId parameter are deleted.
Return value
If the function succeeds, it returns S_OK. If the function fails, it returns an HRESULT value that indicates the error. Possible values include, but are not limited to, those in the following table. For a list of common error codes, see Common HRESULT Values.
| Return code | Description |
|---|---|
|
The session handle is not valid. |
|
The UnitId parameter contains zero or the SubFactor contains WINBIO_SUBTYPE_NO_INFORMATION. |
|
The pointer specified in the Identity parameter cannot be NULL. |
|
The operation could not be completed because the biometric unit is currently being used for an enrollment transaction. |
Remarks
To use WinBioDeleteTemplate synchronously, call the function with a session handle created by calling WinBioOpenSession. The function blocks until the operation completes or an error is encountered.
To use WinBioDeleteTemplate asynchronously, call the function with a session handle created by calling WinBioAsyncOpenSession. The framework allocates a WINBIO_ASYNC_RESULT structure and uses it to return information about operation success or failure. If the deletion operation is successful, the framework returns WINBIO_IDENTITY and WINBIO_BIOMETRIC_SUBTYPE information in a nested DeleteTemplate structure. If the operation is unsuccessful, the framework returns error information. The WINBIO_ASYNC_RESULT structure is returned to the application callback or to the application message queue, depending on the value you set in the NotificationMethod parameter of the WinBioAsyncOpenSession function:
- If you choose to receive completion notices by using a callback, you must implement a PWINBIO_ASYNC_COMPLETION_CALLBACK function and set the NotificationMethod parameter to WINBIO_ASYNC_NOTIFY_CALLBACK.
- If you choose to receive completion notices by using the application message queue, you must set the NotificationMethod parameter to WINBIO_ASYNC_NOTIFY_MESSAGE. The framework returns a WINBIO_ASYNC_RESULT pointer to the LPARAM field of the window message.
Examples
The following code example calls WinBioDeleteTemplate to delete a specific biometric template. Link to the Winbio.lib static library and include the following header files:
- Windows.h
- Stdio.h
- Conio.h
- Winbio.h
HRESULT DeleteTemplate(WINBIO_BIOMETRIC_SUBTYPE subFactor)
{
HRESULT hr = S_OK;
WINBIO_IDENTITY identity = {0};
WINBIO_SESSION_HANDLE sessionHandle = NULL;
WINBIO_UNIT_ID unitId = 0;
// Find the identity of the user.
hr = GetCurrentUserIdentity( &identity );
if (FAILED(hr))
{
wprintf_s(L"\n User identity not found. hr = 0x%x\n", hr);
goto e_Exit;
}
// Connect to the system pool.
//
hr = WinBioOpenSession(
WINBIO_TYPE_FINGERPRINT, // Service provider
WINBIO_POOL_SYSTEM, // Pool type
WINBIO_FLAG_DEFAULT, // Configuration and access
NULL, // Array of biometric unit IDs
0, // Count of biometric unit IDs
NULL, // Database ID
&sessionHandle // [out] Session handle
);
if (FAILED(hr))
{
wprintf_s(L"\n WinBioEnumBiometricUnits failed. hr = 0x%x\n", hr);
goto e_Exit;
}
// Locate the sensor.
//
wprintf_s(L"\n Swipe your finger on the sensor...\n");
hr = WinBioLocateSensor( sessionHandle, &unitId);
if (FAILED(hr))
{
wprintf_s(L"\n WinBioLocateSensor failed. hr = 0x%x\n", hr);
goto e_Exit;
}
// Delete the template identified by the subFactor argument.
//
hr = WinBioDeleteTemplate(
sessionHandle,
unitId,
&identity,
subFactor
);
if (FAILED(hr))
{
wprintf_s(L"\n WinBioDeleteTemplate failed. hr = 0x%x\n", hr);
goto e_Exit;
}
e_Exit:
if (sessionHandle != NULL)
{
WinBioCloseSession(sessionHandle);
sessionHandle = NULL;
}
wprintf_s(L"Press any key to exit...");
_getch();
return hr;
}
//------------------------------------------------------------------------
// The following function retrieves the identity of the current user.
// This is a helper function and is not part of the Windows Biometric
// Framework API.
//
HRESULT GetCurrentUserIdentity(__inout PWINBIO_IDENTITY Identity)
{
// Declare variables.
HRESULT hr = S_OK;
HANDLE tokenHandle = NULL;
DWORD bytesReturned = 0;
struct{
TOKEN_USER tokenUser;
BYTE buffer[SECURITY_MAX_SID_SIZE];
} tokenInfoBuffer;
// Zero the input identity and specify the type.
ZeroMemory( Identity, sizeof(WINBIO_IDENTITY));
Identity->Type = WINBIO_ID_TYPE_NULL;
// Open the access token associated with the
// current process
if (!OpenProcessToken(
GetCurrentProcess(), // Process handle
TOKEN_READ, // Read access only
&tokenHandle)) // Access token handle
{
DWORD win32Status = GetLastError();
wprintf_s(L"Cannot open token handle: %d\n", win32Status);
hr = HRESULT_FROM_WIN32(win32Status);
goto e_Exit;
}
// Zero the tokenInfoBuffer structure.
ZeroMemory(&tokenInfoBuffer, sizeof(tokenInfoBuffer));
// Retrieve information about the access token. In this case,
// retrieve a SID.
if (!GetTokenInformation(
tokenHandle, // Access token handle
TokenUser, // User for the token
&tokenInfoBuffer.tokenUser, // Buffer to fill
sizeof(tokenInfoBuffer), // Size of the buffer
&bytesReturned)) // Size needed
{
DWORD win32Status = GetLastError();
wprintf_s(L"Cannot query token information: %d\n", win32Status);
hr = HRESULT_FROM_WIN32(win32Status);
goto e_Exit;
}
// Copy the SID from the tokenInfoBuffer structure to the
// WINBIO_IDENTITY structure.
CopySid(
SECURITY_MAX_SID_SIZE,
Identity->Value.AccountSid.Data,
tokenInfoBuffer.tokenUser.User.Sid
);
// Specify the size of the SID and assign WINBIO_ID_TYPE_SID
// to the type member of the WINBIO_IDENTITY structure.
Identity->Value.AccountSid.Size = GetLengthSid(tokenInfoBuffer.tokenUser.User.Sid);
Identity->Type = WINBIO_ID_TYPE_SID;
e_Exit:
if (tokenHandle != NULL)
{
CloseHandle(tokenHandle);
}
return hr;
}
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.h (include Winbio.h) |
| Library | Winbio.lib |
| DLL | Winbio.dll |