Unregisters a callback with the corresponding query condition by using the handle, so that no callback is triggered when the media attributes change.
- Parameters
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| type | boolean | Yes| Must enter the string **change**.|
| callback | Callback<MediaQueryResult> | No| Callback to be unregistered. If the default value is used, all callbacks of the handle are unregistered.|
- Example
```
import mediaquery from '@ohos.mediaquery'
listener = mediaquery.matchMediaSync('(orientation: landscape)'); // Listen for landscape events.