---
title: HandleChangeScalarValue
framework: audiodriverkit
role: symbol
role_heading: Instance Method
path: audiodriverkit/iouseraudiolevelcontrol/handlechangescalarvalue
---

# HandleChangeScalarValue

Tells the slider control the scalar value is changing.

## Declaration

```occ
virtual kern_return_t HandleChangeScalarValue(float in_scalar_value);
```

## Parameters

- `in_scalar_value`: The new scalar value to set.

## Return Value

Return Value kIOReturnSuccess on success, or another value if an error occurs. For a list of error codes, see Error Codes.

## Discussion

Discussion The default implementation calls SetScalarValue and returns kIOReturnSuccess. Subclass and override this method to handle changes to the stream format and return kIOReturnSuccess upon success.

## See Also

### Supporting Value Changes

- [HandleChangeDecibelValue](audiodriverkit/iouseraudiolevelcontrol/handlechangedecibelvalue.md)