---
title: AddCustomProperty
framework: audiodriverkit
role: symbol
role_heading: Instance Method
path: audiodriverkit/iouseraudiocustomproperty/addcustomproperty
---

# AddCustomProperty

Attempts to add a custom property to the custom property.

## Declaration

```occ
virtual kern_return_t AddCustomProperty(IOUserAudioCustomProperty *in_custom_property);
```

## Parameters

- `in_custom_property`: An doc://com.apple.audiodriverkit/documentation/AudioDriverKit/IOUserAudioCustomProperty object to add to the doc://com.apple.audiodriverkit/documentation/AudioDriverKit/IOUserAudioCustomProperty.

## Return Value

Return Value kIOReturnError

## Discussion

Discussion This method always returns kIOReturnError since a custom property can’t have a custom property.

## See Also

### Infrequently Used Functionality

- [RemoveCustomProperty](audiodriverkit/iouseraudiocustomproperty/removecustomproperty.md)