System Screenshot Detection

Screenshot Callback

Important Notes

Android Requirements: Storage permissions are required for proper functionality
Device Validation: Requires physical device testing for screenshot verification

Flutter Implementation Considerations

When overriding didChangeAppLifecycleState in Flutter:

On Samsung devices, side-edge screenshots trigger the resumed lifecycle state

Implement screenshot handling accordingly:

case AppLifecycleState.resumed: // App visible (foreground)
  _screenshotCallback.startScreenshot();
  break;

case AppLifecycleState.paused: // App not visible (background)
  _screenshotCallback.stopScreenshot();
  break;

HarmonyOS Implementation Code

Screenshot Listener

```typescript
/**
 * Sets screenshot detection listener
 *
 * @param listener Callback handler
 */
setListener(listener: OnScreenShotListener | null) {
  this.mListener = listener
}

private onCallback: Callback<photoAccessHelper.ChangeData> = (changeData) => {
  if (changeData && 
  changeData.type == photoAccessHelper.NotifyType.NOTIFY_ADD && 
  changeData.uris) {

Log.i(TAG, `Detected screenshot: ${changeData.uris}`);

for (let photo of changeData.uris) {
  if (photo && photo.indexOf(SCREENSHOT_PREFIX) > 0) {
this.mListener && this.mListener.onShot(photo)
break
  }
}
  }
}
```

Start Screenshot Detection

```typescript
/**
 * Enables screenshot detection
 *
 * @param windowClass Window context
 */
async startListen(windowClass: window.Window | null): Promise<void> {
  if (!windowClass) {
Log.w(TAG, "startListen: Window context missing")
return
  }

  Log.i(TAG, "Starting screenshot detection")

  abilityAccessCtrl.createAtManager()
.requestPermissionsFromUser(this.uiAbility?.context, 
['ohos.permission.READ_IMAGEVIDEO'], 
async (err: BusinessError, data: PermissionRequestResult) => {
  if (err) {
Log.e(TAG, `Permission request failed: ${JSON.stringify(err)}`);
this.mListener && this.mListener.onScreenCapturedWithDeniedPermission()
  } else {
Log.i(TAG, `Permission granted: ${data?.permissions?.toString()}}`);
this.phAccessHelper?.registerChange(
  photoAccessHelper.DefaultChangeUri.DEFAULT_PHOTO_URI, 
  true, 
  this.onCallback
);
  }
});
}
```

Stop Screenshot Detection

```typescript
/**
 * Disables screenshot detection
 */
stopListen(): void {
  Log.i(TAG, "Stopping screenshot detection")
  this.phAccessHelper?.unRegisterChange(
photoAccessHelper.DefaultChangeUri.DEFAULT_PHOTO_URI, 
this.onCallback
  );
}
```