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# HandleChangeControlValue

The system calls this virtual method when the control’s value changes.

```
virtual kern_return_t HandleChangeControlValue(bool in_control_value);
```

## Parameters

`in_control_value`

The Boolean value attempting to be set on the control.

## Return Value

`kIOReturnSuccess` on success. Upon success the control’s value should be updated.

## Discussion

The default implementation calls SetControlValue() and returns `kIOReturnSuccess`.
Subclass and override this method to handle changes to this control value and
return `kIOReturnSuccess` upon success.

---

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