如何使用块动画使 UINavigationBar 中的 UISearchBar 仅调整左边距的大小？

我正在尝试复制移动 Safari 中看到的 UISearchBar 动画。 UISearchBar 不是仅移动左边距，而是展开屏幕，然后“跳”到正确的位置。裁员同样不平衡。我怎样才能让这个动画像移动Safari中的UISearchBar一样？

searchBar = [[[UISearchBar alloc] initWithFrame:CGRectMake(0,0,175,44)] autorelease];
searchBar.delegate = self;
searchBar.showsCancelButton = YES;
searchBar.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleWidth;
UIBarButtonItem *customBarItemRight = [[[UIBarButtonItem alloc] initWithCustomView:searchBar] autorelease];
tabBarController.navigationItem.rightBarButtonItem = customBarItemRight;


- (void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar {
searchDisplayController.searchResultsTableView.hidden = NO;
[UIView animateWithDuration:.3
animations:^ {
CGRect newBounds = searchBar.bounds;
newBounds.size.width = 350;
searchBar.bounds = newBounds;
}];
[searchDisplayController setActive:YES animated:YES];
}

您不应该为此使用 UISearchDisplayController，您需要为自定义视图控制器实现动画。