UISearchDisplayController 文本更改滞后

Question

我正在尝试搜索我的 Parse 数据库中的用户列表。为此，我有一个搜索栏控制器和 table 视图。当用户搜索时，搜索结果似乎落后了一个字母。例如，如果我搜索 "Be" 它将显示所有以 "B" 开头的名称而不是 "Be" 并且当我搜索 "Ben" 时它显示所有以 [=18= 开头的用户].

这是我的 textDidChange 方法：

-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText{

NSString *string = searchText;
string = string.lowercaseString;
if(string.length>0){
        PFUser *currentUser = [PFUser currentUser];
        PFQuery *query = [PFQuery queryWithClassName:@"_User"];
        [query whereKey:@"name_lower" containsString:string];
        [query whereKey:@"username" notEqualTo:currentUser.username];
        [query orderByAscending:@"name_lower"];
        [query setLimit:1000];
        [query findObjectsInBackgroundWithBlock:^(NSArray *array,NSError *error){
            if(!error){
                results = [[NSArray alloc]initWithArray:array];

                [_mainTableView reloadData];

            }else{
                [ProgressHUD showError:@"Error Searching"];
            }
        }];
}else{
    NSLog(@"NO RESULTS");
    results = nil;
    [_mainTableView reloadData];
}

}

然后在我的 cellforrow 中：

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

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];
if (cell == nil) cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:@"cell"];


    PFUser *user = results[indexPath.row];
    [user fetchIfNeeded];



    cell.textLabel.text = [NSString stringWithFormat:@"%@ - @%@",user[@"name"],user[@"username"]];
    cell.detailTextLabel.text = user[@"university"];
}

Answer 1

嘿，试着像这样设置约束：

[query whereKey:@"name_lower" hasPrefix:string];

而不是

[query whereKey:@"name_lower" containsString:string];

毕竟我会这样做:

-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText{

      NSString *string = searchText;
      string = string.lowercaseString;
      if(string.length>0){
          PFQuery *query = [PFUser query];
          [query whereKey:@"name_lower" hasPrefix:string];
          [query whereKey:@"username" notEqualTo:[[PFUser currentUser] username]];
          [query orderByAscending:@"name_lower"];
          [query setLimit:1000];
          [query findObjectsInBackgroundWithBlock:^(NSArray *array,NSError *error){
               if(!error){
                    results = array;

                    [_mainTableView reloadData];

               } else {
                    [ProgressHUD showError:@"Error Searching"];
               }
           }];
      } else {
          NSLog(@"NO RESULTS");
          results = nil;
          [_mainTableView reloadData];
      }
}

UISearchDisplayController 文本更改滞后

UISearchDisplayController Text Did Change Lagging Behind

ios

objective-c

parse-platform

uisearchbar