Question

我是IOS编程的新手，我希望得到你的帮助。首先，我有一个表视图，其中包含NSMutablearray“recs”的对象。我插入了一个UISearchBar，目的是从我想要的recs中找到每个对象。当我尝试键入搜索栏时，它会崩溃并显示以下消息以记录文件

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Can't use in/contains operator with collection <Person: 0x8e20b10> (not a collection)'

我向您展示了包含NSPredicate的代码的一部分：

-(BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString {
// Tells the table data source to reload when text changes
[self filterContentForSearchText:searchString scope:
 [[self.searchDisplayController.searchBar scopeButtonTitles] objectAtIndex:[self.searchDisplayController.searchBar selectedScopeButtonIndex]]];
// Return YES to cause the search result table view to be reloaded.
return YES;

}

-(void)filterContentForSearchText:(NSString*)searchText scope:(NSString*)scope {
// Update the filtered array based on the search text and scope.
// Remove all objects from the filtered search array
[self.searcharray removeAllObjects];
// Filter the array using NSPredicate
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"self contains[cd] %@",searchText];
_searcharray = [NSMutableArray arrayWithArray:[_recs filteredArrayUsingPredicate:predicate]];

}

我很困惑...... 请帮帮我!!!!

Answer 1

错误消息表明您的数组包含Person个对象，而不仅仅是字符串。在这种情况下，您必须指定应该用于搜索的Person类的属性，例如：

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

IOS：NSpredicate与数组和搜索栏

1 个答案: