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# CHHapticPattern.Key

Constants that define the keys you use to create a haptic pattern dictionary.

```
struct Key
```

## Topics

### Haptic Pattern Keys

[`CHHapticPatternKeyEvent`](/documentation/CoreHaptics/CHHapticPattern/Key/event)

A key that identifies the beginning of a haptic event definition.

[`CHHapticPatternKeyEventDuration`](/documentation/CoreHaptics/CHHapticPattern/Key/eventDuration)

A key that identifies the duration of an event.

[`CHHapticPatternKeyEventParameters`](/documentation/CoreHaptics/CHHapticPattern/Key/eventParameters)

A key that identifies the beginning of an array of fixed parameter definitions.

[`CHHapticPatternKeyEventType`](/documentation/CoreHaptics/CHHapticPattern/Key/eventType)

A key that identifies the type of event.

[`CHHapticPatternKeyEventWaveformLoopEnabled`](/documentation/CoreHaptics/CHHapticPattern/Key/eventWaveformLoopEnabled)

A key for a Boolean value that indicates whether to loop custom audio events.

[`CHHapticPatternKeyEventWaveformPath`](/documentation/CoreHaptics/CHHapticPattern/Key/eventWaveformPath)

A key that identifies the path to the local file that contains the audio waveform.

[`CHHapticPatternKeyEventWaveformUseVolumeEnvelope`](/documentation/CoreHaptics/CHHapticPattern/Key/eventWaveformUseVolumeEnvelope)

A key that identifies whether audio file playback fades in and out using an envelope.

[`CHHapticPatternKeyParameter`](/documentation/CoreHaptics/CHHapticPattern/Key/parameter)

A key that identifies the beginning of a parameter definition.

[`CHHapticPatternKeyParameterCurve`](/documentation/CoreHaptics/CHHapticPattern/Key/parameterCurve)

A key that identifies the beginning of a parameter curve definition.

[`CHHapticPatternKeyParameterCurveControlPoints`](/documentation/CoreHaptics/CHHapticPattern/Key/parameterCurveControlPoints)

A key that identifies the control points of a parameter curve.

[`CHHapticPatternKeyParameterID`](/documentation/CoreHaptics/CHHapticPattern/Key/parameterID)

A key that identifies the parameter ID.

[`CHHapticPatternKeyParameterValue`](/documentation/CoreHaptics/CHHapticPattern/Key/parameterValue)

A key that identifies the value of a parameter.

[`CHHapticPatternKeyPattern`](/documentation/CoreHaptics/CHHapticPattern/Key/pattern)

A key that identifies the beginning of a haptic pattern definition.

[`CHHapticPatternKeyTime`](/documentation/CoreHaptics/CHHapticPattern/Key/time)

A key that identifies the relative time for an event or parameter, in seconds.

[`CHHapticPatternKeyVersion`](/documentation/CoreHaptics/CHHapticPattern/Key/version)

A key that identifies rhe version number of a haptic pattern dictionary.

### Initializers

[`init(rawValue:)`](/documentation/CoreHaptics/CHHapticPattern/Key/init(rawValue:))

Creates a pattern key with a string.

## Relationships

### Conforms To

[`Sendable`](/documentation/Swift/Sendable)

[`Hashable`](/documentation/Swift/Hashable)

[`RawRepresentable`](/documentation/Swift/RawRepresentable)

[`Equatable`](/documentation/Swift/Equatable)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

---

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