在Android 12中，虽然FLAG_SECURE无法完全防止截屏，但我们可以通过以下方式去控制截屏的可行性：

1. 使用 WindowInsetsControllerCompat API 来控制系统 UI 的可见性

ViewCompat.getWindowInsetsController(view)?.systemBarsBehavior =
WindowInsetsControllerCompat.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE

2. 通过调用 Activity 的截屏方法，判断截屏回调的状态是否为true，如果为true，则说明已经进行了截屏，可以在回调中进行提示或禁止截屏的操作。

private void takeScreenshot() {
    MediaProjectionManager mediaProjectionManager =
        (MediaProjectionManager) getSystemService(Context.MEDIA_PROJECTION_SERVICE);
    Intent intent = mediaProjectionManager.createScreenCaptureIntent();
    startActivityForResult(intent, SCREENSHOT_REQUEST_CODE);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == SCREENSHOT_REQUEST_CODE) {
        if (resultCode == RESULT_OK) {
            Toast.makeText(this, "Screenshot taken successfully", Toast.LENGTH_LONG).show();
        } else {
            Toast.makeText(this, "Screenshot permission denied", Toast.LENGTH_LONG).show();
        }
    }
}