---
title: "parameterChanged(_:at:)"
framework: Professional Video Applications
role: symbol
role_heading: Instance Method
platforms: [fxplug 4.0+]
path: "professional_video_applications/fxtileableeffect/parameterchanged(_:at:)"
---

# parameterChanged(_:at:)

Executes when the host detects that a parameter has changed.

## Declaration

```swift
optional func parameterChanged(_ paramID: UInt32, at time: CMTime) throws
```

## Parameters

- `paramID`: The ID of the parameter that changed.
- `time`: The rational time at which the parameter changed.

## Mentioned in

Adding parameters to plug-ins Building an FxPlug plug-in manually Thread safety in plug-ins Versioning and obsoleting old plug-ins

## Discussion

Discussion Use this method to change, enable, disable, hide, or show other parameters. This method is called each time the user changes a parameter. You can use this method to update other parameters (such as hiding or showing them). You have full access to the FxParameterCreationAPI_v5 or later, FxParameterRetrievalAPI_v6 or later, and FxParameterSettingAPI_v5 or later, within this method.

## See Also

### Adding and setting parameters

- [addParameters()](professional_video_applications/fxtileableeffect/addparameters().md)
- [class(forCustomParameterID:)](professional_video_applications/fxtileableeffect/class(forcustomparameterid:).md)
- [classes(forCustomParameterID:)](professional_video_applications/fxtileableeffect/classes(forcustomparameterid:).md)