How do I cover the “no results” text in UISearchDisplayController's searchResultTableView?

I don't want to show the "no results" text while my server is processing a search query.

enter image description here

I figured out the exact coordinates of the table cell that contains the label and attempted to cover it.

self.noResultsCoverView = [[[UIView alloc] initWithFrame:CGRectMake(
    0.0, 
    44.0, 
    320.0, 
    43.0
)] autorelease];
self.noResultsCoverView.backgroundColor = [UIColor whiteColor];
[self.searchDisplayController.searchResultsTableView addSubview:self.noResultsCoverView];

To my chagrin, my cover was above the table view, but below the label. I need the cover to be above the label. searchResultsTableView::bringSubviewToFront didn't work, which makes me believe that the label isn't a child of the searchResultsTableView at all.

BTW, this Stack Overflow answer doesn't quite work for me. It works on the very first search, but flashes a weird black cover on subsequent searches.

this should do the work properly. The code to return at least one cell:

BOOL ivarNoResults; // put this somewhere in @interface or at top of @implementation
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    if (tableView == self.searchDisplayController.searchResultsTableView) {
        if (filteredList.count == 0) {
            ivarNoResults = YES;
            return 1;
        } else {
            ivarNoResults = NO;
            return [filteredList count];
        }
    }
    // {…}
    // return the unfiltered array count
}

and for "showing" the clean cell:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{
    if (tableView == self.searchDisplayController.searchResultsTableView && ivarNoResults) {
        static NSString *cleanCellIdent = @"cleanCell";
        UITableViewCell *ccell = [tableView dequeueReusableCellWithIdentifier:cleanCellIdent];
        if (ccell == nil) {
            ccell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cleanCellIdent] autorelease];
            ccell.userInteractionEnabled = NO;
        }
        return ccell;
    }

    // {…}
}

answered Aug 2 '12 at 8:39

relikd
7,48541956

up vote0down vote

You need to realize that when you have a UISearchDisplayController, and the search bar is active, the UITableView argument passed into your UITableView data source and delegate methods is in fact NOT your tableView object, but a tableView managed by theUISearchDisplayController, intended to display "live" search results (perhaps results filtered from your main data source, for example).

You can easily detect this in code, and then return the appropriate result from the delegate/data source method, depending on which tableView object is asking.

For example:

- (NSInteger)tableView:(UITableView *)tv numberOfRowsInSection:(NSInteger)section
{
    if (tv == self.searchDisplayController.searchResultsTableView) {
        // return the number of rows in section for the visible search results.
        // return a non-zero value to suppress "No results"
    } else {
        // return the number of rows in section for your main data source
    }
}

The point is that your data source and delegate methods are serving two tables, and you can (and should) check for which table is asking for data or delegation.

By the way, the "No results" is (I believe) provided by a background image which theUISearchDisplayController displays when the delegate says there are no rows... You are not seeing a 2-row table, the first blank and the second with text "No results". At least, that's what I think is happening there.

answered Jul 27 '12 at 19:53

MarkGranoff
10.2k2338

up vote0down vote

I haven't tried it myself, you can give it a try-- Link

Regards,
Amar

answered Jul 30 '12 at 3:44

Amar
961214

因为产生的UILabel@“No Resulte”有延迟，如果不延迟检测是检测不出来的

up vote-2down vote

Try this it worked for me

In the UISearchDisplayController delegate do this:=

- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, 0.001);
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        for (UIView* v in self.searchDisplayController.searchResultsTableView.subviews) {
            if ([v isKindOfClass: [UILabel class]] && 
                [[(UILabel*)v text] isEqualToString:@"No Results"]) {
                [(UILabel*)v setText:@""];
                break;
            }
        }
    });
    return YES;
}