为什么无法从UIActivityViewController中删除Gmail？

Question

我想从UIActivityViewController中删除Gmail。这是我的以下代码：

ActivityViewController *activityVC = [[ActivityViewController alloc] initWithActivityItems:objectsToShare applicationActivities:nil];
activityVC.completionWithItemsHandler = ^(NSString *activityType, BOOL completed, NSArray *returnedItems, NSError *activityError) {
    NSLog(@"%@", activityType);
};

NSArray *excludeActivities = @[@"com.google.Gmail.ShareExtension"];

activityVC.excludedActivityTypes = excludeActivities;

[self presentViewController:activityVC animated:YES completion:nil];

但Gmail仍在那里！有人建议如何删除？

注意

我从打印日志中获取com.google.Gmail.ShareExtension