WdfRegistryAssignUnicodeString function (wdfregistry.h)

Article
04/18/2022

[Applies to KMDF and UMDF]

The WdfRegistryAssignUnicodeString method assigns a specified Unicode string to a specified value name in the registry.

Syntax

NTSTATUS WdfRegistryAssignUnicodeString(
  [in] WDFKEY           Key,
  [in] PCUNICODE_STRING ValueName,
  [in] PCUNICODE_STRING 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 value name.

[in] Value

A pointer to a UNICODE_STRING structure that contains the string to be assigned to the value name that ValueName specifies.

Return value

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

Return code	Description
STATUS_INVALID_DEVICE_REQUEST	WdfRegistryAssignUnicodeString was not called at IRQL = PASSIVE_LEVEL.
STATUS_INVALID_PARAMETER	An invalid parameter was specified.
STATUS_ACCESS_DENIED	The driver did not open the registry key with KEY_SET_VALUE access.
STATUS_INSUFFICIENT_RESOURCES	There was insufficient memory to complete the operation.

This method also might return other NTSTATUS values.

A bug check occurs if the driver supplies an invalid object handle.

Remarks

If the string that the Value parameter specifies is not NULL-terminated, the framework adds a NULL character when copying the string to the registry.

If the value name that the ValueName parameter specifies already exists, WdfRegistryAssignUnicodeString updates the value's data.

The framework sets the value's data type to REG_SZ.

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

Examples

The following code example assigns a Unicode string "String1" to the ValueName value, under a specified registry key.

UNICODE_STRING ustring1, valueName;
NTSTATUS status;

RtlInitUnicodeString(
                     &ustring1,
                     L"String1"
                     );
RtlInitUnicodeString(
                     &valueName,
                     L"ValueName"
                     );

status = WdfRegistryAssignUnicodeString(
                                        Key,
                                        &valueName,
                                        &string1
                                        );

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)