WdfRegistryCreateKey function (wdfregistry.h)

[Applies to KMDF and UMDF]

The WdfRegistryCreateKey method creates and opens a specified registry key, or just opens the key if it already exists, and creates a framework registry-key object that represents the registry key.

Syntax

NTSTATUS WdfRegistryCreateKey(
  [in, optional]  WDFKEY                 ParentKey,
  [in]            PCUNICODE_STRING       KeyName,
  [in]            ACCESS_MASK            DesiredAccess,
  [in]            ULONG                  CreateOptions,
  [out, optional] PULONG                 CreateDisposition,
  [in, optional]  PWDF_OBJECT_ATTRIBUTES KeyAttributes,
  [out]           WDFKEY                 *Key
);

Parameters

[in, optional] ParentKey

A handle to a framework registry-key object. This object represents a parent registry key that the driver has opened. This parameter is optional and can be NULL. If the parameter is not NULL, the key that KeyName specifies must reside under this parent key in the registry. For more information about this parent key, see the Remarks section.

[in] KeyName

A pointer to a UNICODE_STRING structure that contains the name of the key to be opened. The key name can include path information. If ParentKey is NULL, KeyName must specify a complete path to a registry key.

[in] DesiredAccess

An ACCESS_MASK-typed value that specifies access rights that the driver is requesting for the specified registry key. For a list of access rights that drivers typically use for registry keys, see Opening a Handle to a Registry-Key Object. Your driver must ask for only the types of access that it needs. For example, the driver must not ask for KEY_ALL_ACCESS if it will only read the registry key.

[in] CreateOptions

One or more flags. For information about these flags, see the CreateOptions parameter or ZwCreateKey.

[out, optional] CreateDisposition

A pointer to a location that receives REG_CREATED_NEW_KEY if a new key is created or REG_OPENED_EXISTING_KEY if an existing key is opened. These values are defined in Wdm.h. This pointer is optional and can be NULL.

[in, optional] KeyAttributes

A pointer to a WDF_OBJECT_ATTRIBUTES structure that contains driver-supplied attributes for the new registry-key object. This parameter is optional and can be WDF_NO_OBJECT_ATTRIBUTES.

[out] Key

A pointer to a location that receives a handle to the new registry-key object.

Return value

WdfRegistryCreateKey returns STATUS_SUCCESS if the operation succeeds. Otherwise, the method might return one of the following values:

For a list of other return values that the WdfRegistryCreateKey method might return, see Framework Object Creation Errors.

This method also might return other NTSTATUS values.

Remarks

To obtain a handle to a registry-key object that represents a parent key, your driver can call WdfDriverOpenParametersRegistryKey, WdfDeviceOpenRegistryKey, or WdfFdoInitOpenRegistryKey.

By default, the new registry-key object's parent is the framework driver object that the WdfDriverCreate method creates. You can use the ParentObject member of the WDF_OBJECT_ATTRIBUTES structure to specify a different parent. The framework deletes the registry-key object when it deletes the parent object. If your driver does not change the default parent, the driver should delete the registry-key object when it has finished using the object; otherwise, the registry-key object will remain until the I/O manager unloads your driver.

If your driver does not change the default parent, the driver should call WdfRegistryClose when it has finished using the object; otherwise, the registry-key object will remain until the I/O manager unloads your driver. Alternatively, the driver can call WdfObjectDelete to delete the registry-key object.

For more information about registry-key objects, see Using the Registry in Framework-Based Drivers.

Examples

The following code example opens a driver's software key, and then it creates and opens the myKeyStr registry key, which is located under the driver's software key.

WDFKEY  hKey, subkey;
NTSTATUS  status;
UNICODE_STRING  myKeyStr;

status = WdfDeviceOpenRegistryKey(
                                  device,
                                  PLUGPLAY_REGKEY_DRIVER,
                                  KEY_READ,
                                  WDF_NO_OBJECT_ATTRIBUTES,
                                  &hKey
                                  );
if (NT_SUCCESS(status)){
    RtlInitUnicodeString(
                         &myKeyStr,
                         L"myKeyStr"
                         );
    status = WdfRegistryCreateKey(
                                  hKey,
                                  &myKeyStr,
                                  KEY_READ,
                                  REG_OPTION_NON_VOLATILE,
                                  NULL,
                                  WDF_NO_OBJECT_ATTRIBUTES,
                                  &subkey
                                  );
}

Requirements

See also

ACCESS_MASK

RtlInitUnicodeString

UNICODE_STRING

WDF_OBJECT_ATTRIBUTES

WdfDeviceOpenRegistryKey

WdfDriverCreate

WdfDriverOpenParametersRegistryKey

WdfFdoInitOpenRegistryKey

WdfRegistryOpenKey

ZwCreateKey