Question

我正在尝试将searchBarController添加到我的tableView中。我在构建应用程序时没有收到任何错误，但是当我开始在searchBar中输入时，应用程序会抛出异常并崩溃。

导致崩溃的行在最后一段代码中注释如下。有谁知道这里可能出了什么问题？非常感谢！

我的.h文件的相关部分：

@interface BusinessesViewController : UITableViewController<CLLocationManagerDelegate, 
UISearchDisplayDelegate> {

    IBOutlet UITableView *mainTableView;
    NSArray *businesses;
    NSMutableData *data;
    NSArray *filteredBusinesses;
}

我的viewDidLoad方法的相关部分：

- (void)viewDidLoad {
    filteredBusinesses = [[NSArray alloc]init];
}

NumberOfRowsInSection方法：

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:
(NSInteger)section {

    if (tableView == self.searchDisplayController.searchResultsTableView) {
        return [filteredBusinesses count];
    }
    else {
        return [businesses count];
    }
}

CellForRowAtIndexPath方法：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:
(NSIndexPath *)indexPath {

    BusinessesTableViewCell *cell = (BusinessesTableViewCell *)[tableView 
    dequeueReusableCellWithIdentifier:@"MainCell"];

    if (tableView == self.searchDisplayController.searchResultsTableView) {
        [cell.businessMainLabel setText:[[filteredBusinesses 
        objectAtIndex:indexPath.row]objectForKey:@"name"]];
    }   
    else {
        [cell.businessMainLabel setText:[[businesses 
        objectAtIndex:indexPath.row]objectForKey:@"name"]];
    }

    return cell;
}

Predicate和SearchDisplayController方法：

- (void)filterContentForSearchText:(NSString *)searchText scope:(NSString *)scope {

    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"beginswith[cd] %@", 
    searchText];

    //THIS LINE OF CODE CAUSES THE CRASH
    filteredBusinesses = [businesses filteredArrayUsingPredicate:predicate];
}

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller 
    shouldReloadTableForSearchString:(NSString *)searchString {

    [self filterContentForSearchText:searchString scope:
    [[self.searchDisplayController.searchBar scopeButtonTitles] objectAtIndex:
    [self.searchDisplayController.searchBar selectedScopeButtonIndex]]];
    return YES;
}

Answer 1

您的谓词错误，键缺失。从其他代码看起来好像 businesses中的对象具有＆＃34;名称＆＃34;属性，所以谓词应该是

[NSPredicate predicateWithFormat:@"name BEGINSWITH[cd] %@",  searchText]
                                   ^key   ^operator    ^value

SearchBarController谓词导致崩溃

1 个答案: