UISearchDisplayController and UITableView prototype cell crash

问题

I have a UIViewController setup in a storyboard with a tableview and UISearchDisplayController.

I am trying to use a custom prototype cell from self.tableview (which is connected to main tableview in the storyboard). It works fine if self.tableview had returned at least 1 cell when I load my view, but if self.tableview doesn't load a cell (as there is no data), and I load up the UISearchBar and search, the cellForRowAtIndexPath: method crashes:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    CustomSearchCell *cell = [self.tableView dequeueReusableCellWithIdentifier:@"CustomSearchCell" forIndexPath:indexPath];

    [self configureCell:cell atIndexPath:indexPath];
    return cell;
}

-(void)configureCell:(CustomSearchCell *)cell atIndexPath:(NSIndexPath *)indexPath {
    User *user = [self.fetchedResultsController objectAtIndexPath:indexPath];

    cell.nameLabel.text = user.username;
}

Errors:

*** Assertion failure in -[UITableViewRowData rectForRow:inSection:heightCanBeGuessed:]
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'request for rect at invalid index path (<NSIndexPath: 0x9ef3d00> {length = 2, path = 0 - 0})

My fetchedResultsController seems to have data (1 section, 2 rows) at the point the above method is called. It crashes on the dequeueReusableCellWithIdentifier line.

Any pointers/ideas? It should dequeue the prototype cell from self.tableview, but my guess is there was none created in self.tableview so this is the cause?

回答1:

UISearchDisplayController manages it's own UITableView (filtered table), in addition to having your primary table. The cell identifier in the filtered table doesn't match your primary table. You also want to fetch the cell not by indexPath as both tables can be vastly different from each other with respect to number of rows, etc.

So instead of doing this:

UITableViewCell *cell =
[self.tableView dequeueReusableCellWithIdentifier:CellIdentifier
forIndexPath:indexPath];

instead do this:

UITableViewCell *cell =
[self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];

回答2:

I solved this by duplicating the prototype cell into a new xib:

In viewDidLoad:

[self.searchDisplayController.searchResultsTableView registerNib:[UINib nibWithNibName:@"CustomSearchCell" bundle:[NSBundle mainBundle]] forCellReuseIdentifier:@"CustomSearchCell"];

And updated cellForRowAtIndexPath to use the method's tableview not the original self.tableview:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    CustomSearchCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CustomSearchCell" forIndexPath:indexPath];

    [self configureCell:cell atIndexPath:indexPath];
    return cell;
}

回答3:

This is an old topic, but if anyone runs into the same problem still, for me it was related to having this line in viewDidLoad

self.tableView.estimatedRowHeight = 80;

and at the same time implementing the heightForRowAtIndexPath delegate method with variable heights in different conditions

if (indexPath.row == 0) {
    return 44 + cellTopSpacing;
} else {
    return 44;
}

Removing the estimated row height solved it.

回答4:

If you use à UISearchDisplayController in the methode celForRowAtIndexPath, you must use the tableView parameter methode and not the retain pointer of the controller.

try with this code

(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    CustomSearchCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CustomSearchCell" forIndexPath:indexPath];

来源：https://stackoverflow.com/questions/18560300/uisearchdisplaycontroller-and-uitableview-prototype-cell-crash

标签

iphone

ios

objective-c

uitableview

uisearchdisplaycontroller