为什么UISearchBar显示不正确？

Question

为了了解UISearchDisplayController是如何工作的，我写在viewDidLoad方法如下代码：

UISearchBar * searchBar = [[[UISearchBar alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 40.0f)] autorelease]; 
searchBar.delegate = self; 
searchBar.showsCancelButton = YES; 

_searchController = [[UISearchDisplayController alloc] initWithSearchBar:searchBar contentsController:self]; 
_searchController.delegate = self; 
_searchController.searchResultsDataSource = self; 
_searchController.searchResultsDelegate = self; 

[_searchController setActive:YES animated:YES]; 
[_searchController.searchBar becomeFirstResponder]; 

但是当我运行我的代码的UISearchBar不被显示，你可以在图片中看到。

Answer 1

创建UISearchBarcontroller它不错，但在UIViewController中没有添加。所以你可以在uiviewcontroller中添加UISearchBarcontroller。

编码：

[self.view addsubview：_searchController];