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# FxCustomParameterViewHost_v2

Defines the methods a plug-in needs to implement to associate a custom NSView with one of its parameters.

```
protocol FxCustomParameterViewHost_v2
```

## Overview

An FxPlug that wants to present custom UI for one or more of its parameters must conform to the FxCustomParmeterViewHost protocol. This protocol allows the plug-in to provide a subclass of NSView. It is up to the plug-in to handle NSEvents in its custom view(s). When an event in a custom view necessitates a change to the value of the associated parameter, the plug-in then uses methods in the host API FxCustomParameterActionAPI to tell the host application to change the parameter value.

## Topics

### Instance Methods

[`func createView(forParameterID: UInt32) -> NSView!`](/documentation/professional_video_applications/FxCustomParameterViewHost_v2/createView(forParameterID:))

Provides an NSView to be associated with the given parameter.


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