iOS 8中不推荐使用searchDisplayController

Question

如何纠正以下错误，使警告不会出现？我遗漏了什么？

当将searchResultsController更正为searchController时，它给我一个错误"object not found“

if (tableView == self.searchDisplayController.searchResultsTableView) {
        cell.textLabel.text = [searchResults objectAtIndex:indexPath.row];
    } else {
        cell.textLabel.text = [_content objectAtIndex:indexPath.row];
    }

    return cell;
}

-(BOOL)searchDisplayController:(UISearchDisplayController *)controller
  shouldReloadTableForSearchString:(NSString *)searchString
{
    [self filterContentForSearchText:searchString
                               scope:[[self.searchDisplayController.searchBar scopeButtonTitles]
                       objectAtIndex:[self.searchDisplayController.searchBar selectedScopeButtonIndex]]];
    return YES;
}

Answer 1

UISearchController类取代了UISearchDisplayController类，用于管理与搜索相关的界面的显示。

来源：https://developer.apple.com/library/ios/releasenotes/General/WhatsNewIniOS/Articles/iOS8.html

所以，正如rmaddy所说的，如果你想摆脱过时的警告，那就停止使用过时的类。请改用UISearchController：

https://developer.apple.com/library/ios/documentation/UIKit/Reference/UISearchController/index.html#//apple_ref/occ/cl/UISearchController

Answer 2

将此代码添加到.h文件中

<UISearchBarDelegate,UISearchResultsUpdating>

NSArray *searchResultsArray;
NSMutableArray *userMutableArray;

@property (retain, nonatomic) UISearchController *searchController;

并将其添加到您的.m文件中

userMutableArray = [[NSMutableArray alloc] initWithObjects:@"Jack",@"Julie", nil];
searchResultsArray = [[NSArray alloc]init];

self.searchController = [[UISearchController alloc]initWithSearchResultsController:nil];
self.searchController.searchBar.scopeButtonTitles = [[NSArray alloc]initWithObjects:@"UserId", @"JobTitleName", nil];
self.searchController.searchBar.delegate = self;
self.searchController.searchResultsUpdater = self;
[self.searchController.searchBar sizeToFit];
self.searchController.dimsBackgroundDuringPresentation = NO;
self.definesPresentationContext = YES;
self.tableView.tableHeaderView = self.searchController.searchBar;


-(void)updateSearchResultsForSearchController:(UISearchController *)searchController{
    NSString *searchString = self.searchController.searchBar.text;
    NSPredicate *resultPredicate;
    NSInteger scope = self.searchController.searchBar.selectedScopeButtonIndex;
    if(scope == 0){
        resultPredicate = [NSPredicate predicateWithFormat:@"userId contains[c] %@",searchString];
    }else{
        resultPredicate = [NSPredicate predicateWithFormat:@"jobTitleName contains[c] %@",searchString];
    }
    searchResultsArray = [userMutableArray filteredArrayUsingPredicate:resultPredicate];
    [self.tableView reloadData];
}

- (void)searchBar:(UISearchBar *)searchBar selectedScopeButtonIndexDidChange:(NSInteger)selectedScope{
    [self updateSearchResultsForSearchController:self.searchController];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    if(self.searchController.active){
        return [searchResultsArray count];
    }else{
        return [userMutableArray count];
    }
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *cellIdentifier;
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if(!cell){
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
    }
    if(self.searchController.active){
        cell.textLabel.text = [searchResultsArray objectAtIndex:indexPath.row];
    }else{
        cell.textLabel.text = [userMutableArray objectAtIndex:indexPath.row];
    }
    return cell;
}

Answer 3

我希望从UISearchDisplayController迁移到UISearchController。所以，我在GitHub上找到了这个：https://github.com/dempseyatgithub/Sample-UISearchController

下载/克隆它，您将能够看到如何在UITableView和UICollectionView中使用UISearchController。

它拥有从UISearchDisplayController升级到UISearchController所需的一切。

UISearchController文档也非常有用。作为入门指南，请查看Sample-UISearchController/MasterViewController_TableResults.m和Sample-UISearchController/MasterViewController_FilterResults.m

如果你还需要支持iOS 7(如果你真的要把你的应用部署到应用商店，我个人推荐)，那么这样做：

if([UISearchController class]){
//Create an UISearchController and add it to your UITableViewController
}else{
//Create an UISearchDisplayController and add it to your UITableViewController 
}

注意:如果你想同时支持两个版本的iOS，你必须通过编程来完成所有的工作。