filterContentForSearchText:scope: 方法从何而来？

Question

最近，我注意到filterContentForSearchText:scope: 出现在多个关于如何实现搜索栏的教程中。

但是，我查找了 UISearchDisplayDelegate and UISearchBarDelegate 的引用。我发现这个filterContentForSearchText:scope: 既不是必需的也不是可选的方法。

我想知道filterContentForSearchText:scope:是否只是过滤搜索结果的常规方法名称？

Answer 1

是的，这只是从UISearchDisplayDelegate 方法调用的常用方法的约定

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString;
- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchScope:(NSInteger)searchOption;

当前"Simple UISearchBar with State Restoration" Apple 的示例项目不使用此约定：

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

    NSInteger selectedScopeButtonIndex = [self.searchDisplayController.searchBar selectedScopeButtonIndex];
    if (selectedScopeButtonIndex > 0)
    {
        scope = [[APLProduct deviceTypeNames] objectAtIndex:(selectedScopeButtonIndex - 1)];
    }

    [self updateFilteredContentForProductName:searchString type:scope];

    // Return YES to cause the search result table view to be reloaded.
    return YES;
}