UISearchDisplayController-如何在只选择了“按范围”按钮但搜索字符串为空的情况下显示搜索结果

当您点击一个新的范围按钮时,selectedScopeButtonIndex将触发:

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

您可以使用以下方法在搜索中捕获标题:

[[self.searchDisplayController.searchBar scopeButtonTitles] objectAtIndex:searchOption]

我也在追求同样的东西,只是在苹果开发者论坛上发现了一些东西:the UISearchDisplayController

我在搜索栏下面放了一个分段控件,模仿范围栏来解决这个问题。

你需要实施 searchBar:textDidChange searchBar:selectedScopeButtonIndexDidChange:

// scope All doesn't do a search until you type something in, so don't show the search table view
// scope Faves and Recent will do a search by default
#define kSearchScopeAll 0
#define kSearchScopeFaves 1
#define kSearchScopeRecent 2

// this gets fired both from user interaction and from programmatically changing the text
- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText{
    [self initiateSearch];
}


- (void)searchBar:(UISearchBar *)searchBar selectedScopeButtonIndexDidChange:(NSInteger)selectedScope{
    NSString *searchText = self.searchDisplayController.searchBar.text;
    // if we got here by selecting scope all after one of the others with no user input, there will be a space in the search text

    NSString *strippedText = [searchText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    if ((selectedScope == kSearchScopeAll) && (strippedText.length == 0) && (searchText.length != 0)){ 
        self.searchDisplayController.searchBar.text = @"";
    } else {
        [self initiateSearch];
    }
}

-(void)initiateSearch{
    NSString *searchText = self.searchDisplayController.searchBar.text;
    NSInteger scope = self.searchDisplayController.searchBar.selectedScopeButtonIndex;
    if ((searchText.length == 0) && (scope != kSearchScopeAll)){
        self.searchDisplayController.searchBar.text = @" ";
    }
    switch (scope) {
        case kSearchScopeAll:
            [self searchAll:searchText];
            break;
        case kSearchScopeFaves:
            [self searchFavorites:searchText];
            break;
        case kSearchScopeRecent:
            [self searchRecents:searchText];
            break;

        default:
            break;
    }
}

// assume these trim whitespace from the search term
-(void)searchAll:(NSString *)searchText{
}

-(void)searchFavorites:(NSString *)searchText{
}

-(void)searchRecents:(NSString *)searchText{
}