Ios UIActivityViewController显示不必要的行

我在UIActivityViewController上收到一条不必要的线路。在我看来，UIActivityViewController有一个上边框，因为当我将其滚动到顶部时，它会移动到顶部，然后再次移动到屏幕截图中显示的实际位置。 代码：

NSURL *myWebsite = [NSURL URLWithString:@"https://www.google.com"];
NSArray *objectsToShare = @[myWebsite];
UIActivityViewController *activityVC = [[UIActivityViewController alloc] initWithActivityItems:objectsToShare applicationActivities:nil];
NSArray *excludeActivities = @[UIActivityTypeAirDrop,
                               UIActivityTypeAssignToContact,
                               UIActivityTypeSaveToCameraRoll,
                               UIActivityTypeAddToReadingList];
activityVC.excludedActivityTypes = excludeActivities;
[self presentViewController:activityVC animated:YES completion:nil];