WdfRegistryQueryULong function (wdfregistry.h)
[Applies to KMDF and UMDF]
The WdfRegistryQueryULong method retrieves the unsigned long word (REG_DWORD) data that is currently assigned to a specified registry value and copies the data to a specified location.
Syntax
NTSTATUS WdfRegistryQueryULong(
[in] WDFKEY Key,
[in] PCUNICODE_STRING ValueName,
[out] PULONG Value
);
Parameters
[in] Key
A handle to a registry-key object that represents an opened registry key.
[in] ValueName
A pointer to a UNICODE_STRING structure that contains a name for the registry value.
[out] Value
A pointer to a location that receives the data that is assigned to the registry value that ValueName specifies.
Return value
WdfRegistryQueryULong returns STATUS_SUCCESS if the operation succeeds. Otherwise, the method might return one of the following values:
Return code | Description |
---|---|
|
WdfRegistryQueryULong was not called at IRQL = PASSIVE_LEVEL. |
|
An invalid parameter was specified. |
|
There was insufficient memory to complete the operation. |
|
The driver did not open the registry key with KEY_QUERY_VALUE, KEY_READ, or KEY_ALL_ACCESS access. |
|
The data type of the registry value that the ValueName parameter specified was not REG_DWORD. |
|
The registry value was not available. |
This method also might return other NTSTATUS values.
A bug check occurs if the driver supplies an invalid object handle.
Remarks
For more information about registry-key objects, see Using the Registry in WDF Drivers.
Examples
The following code example retrieves the data that is currently assigned to the NumberOfThings value.
NTSTATUS status;
ULONG value;
DECLARE_CONST_UNICODE_STRING(valueName, L"NumberOfThings");
status = WdfRegistryQueryULong(
hKey,
&valueName,
&value
);
Requirements
Requirement | Value |
---|---|
Target Platform | Universal |
Minimum KMDF version | 1.0 |
Minimum UMDF version | 2.0 |
Header | wdfregistry.h (include Wdf.h) |
Library | Wdf01000.sys (KMDF); WUDFx02000.dll (UMDF) |
IRQL | PASSIVE_LEVEL |
DDI compliance rules | DriverCreate(kmdf), KmdfIrql(kmdf), KmdfIrql2(kmdf), KmdfIrqlExplicit(kmdf) |