---
title: "DARegisterDiskDescriptionChangedCallback(_:_:_:_:_:)"
framework: Disk Arbitration
role: symbol
role_heading: Function
platforms: [Mac Catalyst 13.1+, macOS 10.4+]
path: "diskarbitration/daregisterdiskdescriptionchangedcallback(_:_:_:_:_:)"
---

# DARegisterDiskDescriptionChangedCallback(_:_:_:_:_:)

Registers a callback function to be called whenever a disk description has changed.

## Declaration

```swift
func DARegisterDiskDescriptionChangedCallback(_ session: DASession, _ match: CFDictionary?, _ watch: CFArray?, _ callback: DADiskDescriptionChangedCallback, _ context: UnsafeMutableRawPointer?)
```

## Parameters

- `session`: The session object.
- `match`: The disk description keys to match. Pass NULL for all disk objects.
- `watch`: The disk description keys to watch. Pass NULL for all keys.
- `callback`: The callback function to call when a watched key changes.
- `context`: The user-defined context parameter to pass to the callback function.

## See Also

### Miscellaneous

- [DADiskClaim(_:_:_:_:_:_:)](diskarbitration/dadiskclaim(_:_:_:_:_:_:).md)
- [DADiskEject(_:_:_:_:)](diskarbitration/dadiskeject(_:_:_:_:).md)
- [DADiskGetOptions(_:)](diskarbitration/dadiskgetoptions(_:).md)
- [DADiskIsClaimed(_:)](diskarbitration/dadiskisclaimed(_:).md)
- [DADiskMount(_:_:_:_:_:)](diskarbitration/dadiskmount(_:_:_:_:_:).md)
- [DADiskMountWithArguments(_:_:_:_:_:_:)](diskarbitration/dadiskmountwitharguments(_:_:_:_:_:_:).md)
- [DADiskRename(_:_:_:_:_:)](diskarbitration/dadiskrename(_:_:_:_:_:).md)
- [DADiskSetOptions(_:_:_:)](diskarbitration/dadisksetoptions(_:_:_:).md)
- [DADiskUnclaim(_:)](diskarbitration/dadiskunclaim(_:).md)
- [DADiskUnmount(_:_:_:_:)](diskarbitration/dadiskunmount(_:_:_:_:).md)
- [DARegisterDiskAppearedCallback(_:_:_:_:)](diskarbitration/daregisterdiskappearedcallback(_:_:_:_:).md)
- [DARegisterDiskDisappearedCallback(_:_:_:_:)](diskarbitration/daregisterdiskdisappearedcallback(_:_:_:_:).md)
- [DARegisterDiskEjectApprovalCallback(_:_:_:_:)](diskarbitration/daregisterdiskejectapprovalcallback(_:_:_:_:).md)
- [DARegisterDiskMountApprovalCallback(_:_:_:_:)](diskarbitration/daregisterdiskmountapprovalcallback(_:_:_:_:).md)
- [DARegisterDiskPeekCallback(_:_:_:_:_:)](diskarbitration/daregisterdiskpeekcallback(_:_:_:_:_:).md)