我有一个tableview
充满 afetchedresultscontroller
和 a searchbar
。到目前为止,在创建应用程序时,我只使用了 7 个单元格并且工作得很好,但是自从我开始使用超过 7 个单元格后,当我触摸搜索栏时,我得到了超出范围空数组的错误。但是当我把它放回 7 个单元格时,它工作得很好。
什么可能是错的?
错误:由于未捕获的异常“ NSRangeException
”而终止应用程序,原因:“ * -[__NSArrayM objectAtIndex:]:
索引 2 超出了空数组的范围”
- (void)viewDidLoad
{
[super viewDidLoad];
self.title = @"Exercises";
id appDelegate = [[UIApplication sharedApplication] delegate];
_managedObjectContext = [appDelegate managedObjectContext];
NSError *error;
if (![[self fetchedResultsController] performFetch:&error]) {
NSLog(@"%@ %@", error, [error userInfo]);
abort();
}
_searchResults = [[NSMutableArray alloc] init];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
NSIndexPath *selectedIndexPath = [_tableView indexPathForSelectedRow];
if (!selectedIndexPath) {
[_tableView setContentOffset:CGPointMake(0, 44) animated:NO];
}
else {
[_tableView deselectRowAtIndexPath:selectedIndexPath animated:YES];
}
}
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
if (self.searchDisplayController.isActive) {
[self.searchDisplayController setActive:NO animated:YES];
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
#pragma mark - UITableViewDataSource
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
if (self.searchDisplayController.isActive) {
return 1;
}
return [[_fetchedResultsController sections] count];
}
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
if (self.searchDisplayController.isActive) {
return nil;
}
return [[[_fetchedResultsController sections] objectAtIndex:section] name];
}
- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 22)];
view.backgroundColor = [UIColor colorWithRed:20.0/255.0 green:20.0/255.0 blue:20.0/255.0 alpha:0.8];
UILabel *sectionLabel = [[UILabel alloc] initWithFrame:CGRectMake(20, 0, 160, 22)];
sectionLabel.font = [UIFont fontWithName:@"Avenir-Book" size:16.0f];
sectionLabel.text = @"Search Results";
if (!self.searchDisplayController.isActive) {
sectionLabel.text = [[[_fetchedResultsController sections] objectAtIndex:section] name];
}
sectionLabel.backgroundColor = [UIColor clearColor];
sectionLabel.textColor = [UIColor whiteColor];
[view addSubview:sectionLabel];
return view;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
if (self.searchDisplayController.isActive) {
return [_searchResults count];
}
return [[[_fetchedResultsController sections] objectAtIndex:section] numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *cellIdentifier = @"exerciseCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
[self stampCell:cell atIndexPath:indexPath];
}
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
#pragma mark - Cell
- (void)stampCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
if ([cell.reuseIdentifier isEqualToString:@"exerciseCell"]) {
UILabel *textLabel = [[UILabel alloc] initWithFrame:CGRectMake(70, 2, 150, 22)];
textLabel.tag = kExerciseCellTextLabel;
textLabel.font = [UIFont systemFontOfSize:18.0];
textLabel.textColor = [UIColor blackColor];
textLabel.highlightedTextColor = [UIColor whiteColor];
textLabel.backgroundColor = [UIColor clearColor];
[cell.contentView addSubview:textLabel];
UILabel *detailTextLabel = [[UILabel alloc] initWithFrame:CGRectMake(70, 24, 150, 18)];
detailTextLabel.tag = kExerciseCellDetailTextLabel;
detailTextLabel.font = [UIFont systemFontOfSize:14.0];
detailTextLabel.textColor = [UIColor colorWithRed:128.0/255.0 green:128.0/255.0 blue:128.0/255.0 alpha:1.0];
detailTextLabel.highlightedTextColor = [UIColor colorWithRed:127.0/255.0 green:127.0/255.0 blue:127.0/255.0 alpha:1.0];
detailTextLabel.backgroundColor = [UIColor clearColor];
[cell.contentView addSubview:detailTextLabel];
}
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
if ([cell.reuseIdentifier isEqualToString:@"exerciseCell"]) {
UILabel *textLabel = (UILabel *)[cell.contentView viewWithTag:kExerciseCellTextLabel];
UILabel *detailTextLabel = (UILabel *)[cell.contentView viewWithTag:kExerciseCellDetailTextLabel];
Exercise *exercise;
if (self.searchDisplayController.isActive) {
exercise = [_searchResults objectAtIndex:indexPath.row];
}
else {
exercise = [_fetchedResultsController objectAtIndexPath:indexPath];
}
textLabel.text = [exercise valueForKey:kExerciseName];
detailTextLabel.text = [NSString stringWithFormat:@"%@ - %@", [[exercise valueForKey:kExerciseEType] valueForKey:kExerciseTypeName], [[exercise valueForKey:kExerciseGear] valueForKey:kGearName]];
cell.selectionStyle = UITableViewCellSelectionStyleGray;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
}
#pragma mark - UITableViewDelegate
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[self performSegueWithIdentifier:@"exerciseDetail" sender:self];
}
#pragma mark - UISearchBarDelegate
- (BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString
{
[_searchResults removeAllObjects];
if (searchString.length > 0) {
for (Exercise *exercise in [_fetchedResultsController fetchedObjects]) {
NSRange range = [[exercise valueForKey:kExerciseName] rangeOfString:searchString options:NSCaseInsensitiveSearch];
if (range.location == 0) {
[_searchResults addObject:exercise];
}
}
}
return YES;
}
- (BOOL)searchBarShouldBeginEditing:(UISearchBar*)searchBar {
[super setPan];
return YES;
}
- (BOOL)searchBarShouldEndEditing:(UISearchBar *)searchBar
{
[super setPan];
return YES;
}
#pragma mark - NSFetchedResultsControllerDelegate
- (NSFetchedResultsController *)fetchedResultsController
{
if (_fetchedResultsController) {
return _fetchedResultsController;
}
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:kExercise inManagedObjectContext:_managedObjectContext];
[request setEntity:entity];
NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:kExerciseName ascending:YES];
[request setSortDescriptors:[NSArray arrayWithObject:sort]];
NSFetchedResultsController *fetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:_managedObjectContext sectionNameKeyPath:kExerciseFirstLetter cacheName:@"ExerciseList"];
[self setFetchedResultsController:fetchedResultsController];
[_fetchedResultsController setDelegate:self];
return _fetchedResultsController;
}
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView beginUpdates];
}
- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
switch(type) {
case NSFetchedResultsChangeInsert:
[self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
newIndexPath:(NSIndexPath *)newIndexPath
{
UITableView *tableView = self.tableView;
switch(type) {
case NSFetchedResultsChangeInsert:
[tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeDelete:
[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
case NSFetchedResultsChangeUpdate:
[self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath];
break;
case NSFetchedResultsChangeMove:
[tableView deleteRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
[tableView insertRowsAtIndexPaths:@[newIndexPath] withRowAnimation:UITableViewRowAnimationFade];
break;
}
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[self.tableView endUpdates];
}
@end