UITextField - 未设置新帧（动画时）

Question

我想，将searchField变形为targetFrame。

＃1这不是结果：

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

    return YES;
}

＃2不正确，但转换：

- (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;
}

然后使用＃2，searchField开始动画，但是为默认大小（不是targetFrame）。

我想，searchField转换为targetFrame。

PS

searchField.autoresizingMask = UIViewAutoresizingNone;没有结果

Answer 1

尝试以下块：

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

   }];