<!--
{
  "availability" : [
    "DriverKit: 21.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "AudioDriverKit",
  "identifier" : "/documentation/AudioDriverKit/IOUserAudioCustomProperty/HandleChangeCustomPropertyDataValueWithQualifier",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
      "AudioDriverKit"
    ],
    "preciseIdentifier" : "c:@S@IOUserAudioCustomProperty@F@HandleChangeCustomPropertyDataValueWithQualifier#*$@S@OSObject#S0_#"
  },
  "title" : "HandleChangeCustomPropertyDataValueWithQualifier"
}
-->

# HandleChangeCustomPropertyDataValueWithQualifier

Tells the property the data value is changing.

```
virtual kern_return_t HandleChangeCustomPropertyDataValueWithQualifier(OSObject *in_qualifier_data, OSObject *in_data);
```

## Parameters

`in_qualifier_data`

The qualifier data <doc://com.apple.documentation/documentation/DriverKit/OSObject> associated with setting the property data value. This can be an <doc://com.apple.documentation/documentation/DriverKit/OSString>, <doc://com.apple.documentation/documentation/DriverKit/OSDictionary>, or `NULL`.

`in_data`

An <doc://com.apple.documentation/documentation/DriverKit/OSObject> to set as the custom property value.

## Return Value

<doc://com.apple.documentation/documentation/DriverKit/kIOReturnSuccess> on success, or another value if an error occurs. For a list of error codes, see <doc://com.apple.documentation/documentation/DriverKit/error-codes>.

## Discussion

The default implementation sets the value and returns <doc://com.apple.documentation/documentation/DriverKit/kIOReturnSuccess>, without checking the qualifier data. Subclass and override this method to handle changes to the custom property and return <doc://com.apple.documentation/documentation/DriverKit/kIOReturnSuccess> upon success.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)