UITextField - not set new frame

问题传送
I want, that searchField deformation to targetFrame.

#1 This not result:

- (BOOL)searchBarShouldBeginEditing:(UISearchBar *)bar
{
    UITextField *searchField = [bar valueForKey:@"_searchField"];
    CGRect targetFrame =  CGRectMake(-50, 0, 200, 30);
    searchField.frame = targetFrame; //not result

    return YES;
}

#2 Incorrect, but transform:

- (BOOL)searchBarShouldBeginEditing:(UISearchBar *)bar
{
    UITextField *searchField = [bar valueForKey:@"_searchField"];
    searchField.frame = CGRectMake (10, 0, 200, 50); //must differ from CGRectZero

    [UIView animateWithDuration: 3.0
                     animations: ^{

                     CGRect targetFrame =  CGRectMake(-50, 0, 200, 30);
                     searchField.frame = targetFrame; 

    }];

    return YES;
}

Then using #2, searchField start animation, but to default size (not to targetFrame).

I want, that searchField transform to targetFrame.

#3 solution

  [UIView animateWithDuration:3.0
                          delay:0
                        options:UIViewAnimationOptionLayoutSubviews
                     animations:^{
                         CGRect targetFrame =  CGRectMake(-50, 0, 200, 30);
                         searchField.frame = targetFrame; 
                     }
                     completion:^(BOOL finished) {

   }];