所以我有UISearchController，它显示栏，我可以输入文本，但它不触发委托方法。这是我的代码：
@IBAction func searchTapped(AnyObject) {
NSLog("search...")
let cancelButton = UIBarButtonItem(image: UIImage(named: "delete_sign-50"), landscapeImagePhone: nil, style: .Plain, target: self, action: "cancelTapped:")
var searchController = UISearchController(searchResultsController: nil)
searchController.dimsBackgroundDuringPresentation = false
searchController.searchBar.placeholder = "enter the text to search"
searchController.searchResultsUpdater = self;
searchController.hidesNavigationBarDuringPresentation = false
searchController.delegate = self
searchController.searchBar.delegate = self
self.definesPresentationContext = true;
UIView.animateWithDuration(0.2, animations: { () -> Void in
self.navigationItem.rightBarButtonItems = nil
self.navigationItem.rightBarButtonItems = [cancelButton]
self.navigationItem.titleView = searchController.searchBar
searchController.searchBar.sizeToFit()
self.toolbar.hidden = false
self.tableView?.hidden = false
})
//add first responser to search bar
searchController.searchBar.becomeFirstResponder()
}
func updateSearchResultsForSearchController(searchController: UISearchController) {
NSLog("1 %@", searchController.searchBar.text);
}
func searchBar(searchBar: UISearchBar, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
NSLog("2 %@", text)
return true
}
当文本更改时，这些方法都不会被调用。
除此之外，我还尝试将searchController作为变量添加到我的控制器中，在这种情况下，它会疯狂地工作——当我点击搜索栏时，它会离开屏幕。
searchController.active = YES;
这起到了帮助作用，但不确定为什么它在任何地方都没有被提及。
对于IOS 9
-(void )viewDidLoad
_searchController = [[UISearchController alloc] initWithSearchResultsController:self];
self.navigationItem.titleView = _searchController.searchBar;
self.definesPresentationContext = YES;
_searchController.delegate = self;
_searchController.searchBar.delegate = self;
_searchController.searchBar.placeholder = NSLocalizedString(@"SEARCHTITLE", nil);
[_searchController.searchBar setShowsCancelButton: YES animated: NO];