為什么我的UISearchController委托方法沒有被調用？

Question

我在課堂上加入了以下內容：

@interface DiscoverNew() <UISearchResultsUpdating, UISearchBarDelegate, UISearchControllerDelegate>

我在這里設置了UISearchController ：

-(void)viewDidLoad {

       [self configureSearchController];

}  

-(void)configureSearchController{

        // Initialize and perform a minimum configuration to the search controller.
        UISearchController *searchController = self.searchController;
        searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
        searchController.searchResultsUpdater = self;
        searchController.dimsBackgroundDuringPresentation = NO;
        searchController.searchBar.placeholder = @"Search for friends...";
        searchController.delegate = self;
        searchController.searchBar.delegate = self;
        [searchController.searchBar sizeToFit];

        [searchController.searchBar setBarStyle:UIBarStyleBlack];
        [searchController.searchBar setSearchBarStyle:UISearchBarStyleMinimal];
        searchController.searchBar.tintColor = [GBColor accentGray];
        searchController.searchBar.backgroundColor = [GBColor darkGray];
        searchController.searchBar.barTintColor = [GBColor accentGray];
        searchController.searchBar.searchTextPositionAdjustment = UIOffsetMake(18.0f, 0.0f);

        // Place searchbar above TableView
        self.tableView.tableHeaderView = searchController.searchBar;

}

如您所見，我將其稱為searchController.searchBar.delegate = self; 實際上， searchController確實出現在應有的位置，並且在輕按搜索欄時會顯示鍵盤，但是沒有調用我的委托方法。 這是怎么回事？

Answer 1

您有一個名為searchController的屬性。 但是，然后您在configureSearchController方法中創建了一個同名的局部變量。 因此，最后您永遠都不會設置searchController屬性。 結果，您在本地創建的搜索控制器超出范圍，沒有更多引用並被釋放。

解決方法是稍微更新您的代碼。

UISearchController *searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
searchController.searchResultsUpdater = self;
searchController.dimsBackgroundDuringPresentation = NO;
searchController.searchBar.placeholder = @"Search for friends...";
searchController.delegate = self;
searchController.searchBar.delegate = self;
[searchController.searchBar sizeToFit];

[searchController.searchBar setBarStyle:UIBarStyleBlack];
[searchController.searchBar setSearchBarStyle:UISearchBarStyleMinimal];
searchController.searchBar.tintColor = [GBColor accentGray];
searchController.searchBar.backgroundColor = [GBColor darkGray];
searchController.searchBar.barTintColor = [GBColor accentGray];
searchController.searchBar.searchTextPositionAdjustment = UIOffsetMake(18.0f, 0.0f);

self.searchController = searchController;