Subscribes to privacy mode changes of this display. When there is a privacy window in the foreground of the display, the display is in privacy mode, and the content in the privacy window cannot be captured or recorded.
| type | string | Yes | Event type. The value is fixed at 'privateModeChange', indicating the event of display privacy mode changes.|
| callback | Callback<boolean> | Yes | Callback used to return whether the privacy mode of the display is changed. The value **true** means that the display changes to the privacy mode, and **false** means the opposite.|
Unsubscribes from privacy mode changes of this display. When there is a privacy window in the foreground of the display, the display is in privacy mode, and the content in the privacy window cannot be captured or recorded.
| type | string | Yes | Event type. The value is fixed at **'privateModeChange'**, indicating the event of display private mode changes.|
| callback | Callback<boolean> | No | Callback used to return whether the privacy mode of the display is changed. The value **true** means that the display changes to the privacy mode, and **false** means the opposite.|
**Example**
```js
try{
display.off("privateModeChange");
}catch(exception){
console.error('Failed to unregister callback. Code: '+JSON.stringify(exception));