我有一个带有两个 uilabels 的自定义表格视图单元格，一切正常启动，但是当我滚动到表格的另一部分并返回时，在任何地方都找不到标签。但是，如果我选择它们，它们会再次显示，直到它们被取消选择
- (id)initWithStyle:(UITableViewStyle)style
{
self = [super initWithStyle:style];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
id appDelegate = [[UIApplication sharedApplication] delegate];
_managedObjectContext = [appDelegate managedObjectContext];
NSError *error;
if (![[self fetchedResultsController] performFetch:&error]) {
NSLog(@"%@ %@", error, [error userInfo]);
abort();
}
_infoView.layer.cornerRadius = 5;
_infoView.layer.masksToBounds = YES;
_infoView.layer.shadowColor = [UIColor colorWithRed:205.0/255.0 green:205.0/255.0 blue:205.0/255.0 alpha:1.0].CGColor;
_infoView.layer.shadowOpacity = 0.8;
_infoView.layer.shadowRadius = 10.0;
_infoView.layer.shadowOffset = CGSizeMake(2.0, 2.0);
_addButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(add:)];
self.navigationItem.rightBarButtonItem = _addButton;
_searchBar.backgroundColor = [UIColor clearColor];
_searchBar.clipsToBounds = YES;
_searchBar.tintColor = [UIColor colorWithRed:200.0/255.0 green:200.0/255.0 blue:200.0/255.0 alpha:1.0];
for (UIView *subview in _searchBar.subviews)
{
if ([subview isKindOfClass:NSClassFromString(@"UISearchBarBackground")])
{
[subview removeFromSuperview];
break;
}
}
_exercisesNumberLabel.text = [NSString stringWithFormat:@"%lu Exercises", (unsigned long)[_fetchedResultsController.fetchedObjects count]];
[_exercisesNumberLabel sizeToFit];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
[self.tableView setContentOffset:CGPointMake(0, _headerView.bounds.size.height)];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)add:(id)sender
{
}
#pragma mark - UITableViewDataSource
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[_fetchedResultsController sections] count];
}
- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
return [[[_fetchedResultsController sections] objectAtIndex:section] name];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
id <NSFetchedResultsSectionInfo> sectionInfo = [[_fetchedResultsController sections] objectAtIndex:section];
return [sectionInfo numberOfObjects];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *cellIdentifier = nil;
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;
}
- (void)stampCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
UILabel *textLabel, *detailTextLabel;
UIButton *playButton;
//UIWebView *miniYouTubeView;
textLabel = [[UILabel alloc] initWithFrame:CGRectMake(70, 2, 170, 22)];
textLabel.tag = kExerciseCellTextLabel;
textLabel.font = [UIFont systemFontOfSize:17.0];
textLabel.textAlignment = NSTextAlignmentLeft;
textLabel.textColor = [UIColor blackColor];
[[cell contentView] addSubview:textLabel];
detailTextLabel = [[UILabel alloc] initWithFrame:CGRectMake(70, 24, 170, 18)];
detailTextLabel.tag = kExerciseCellDetailTextLabel;
detailTextLabel.font = [UIFont systemFontOfSize:14.0];
detailTextLabel.textAlignment = NSTextAlignmentLeft;
detailTextLabel.textColor = [UIColor colorWithRed:128.0/255.0 green:128.0/255.0 blue:128.0/255.0 alpha:1.0];
detailTextLabel.autoresizingMask = UIViewAutoresizingFlexibleRightMargin;
[[cell contentView] addSubview:detailTextLabel];
playButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 64, 44)];
playButton.backgroundColor = [UIColor lightGrayColor];
[playButton setImage:[UIImage imageNamed:@"121-landscape.png"] forState:UIControlStateNormal];
[[cell contentView] addSubview:playButton];
/*miniYouTubeView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 60, 44)];
miniYouTubeView.tag = kExerciseCellMiniYouTubeView;
miniYouTubeView.autoresizingMask = UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleHeight;
[[cell contentView] addSubview:miniYouTubeView];*/
}
#pragma mark - UITableViewDelegate
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
return 44;
}
- (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath
{
if ([[[_fetchedResultsController objectAtIndexPath:indexPath] isDefault] boolValue]) {
return NO;
}
return YES;
}
- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
if (editingStyle == UITableViewCellEditingStyleInsert) {
}
else if (editingStyle == UITableViewCellEditingStyleDelete) {
Exercise *exercise = [_fetchedResultsController objectAtIndexPath:indexPath];
[_managedObjectContext deleteObject:exercise];
NSError *error;
if (![_managedObjectContext save:&error]) {
NSLog(@"%@ %@", error, [error userInfo]);
abort();
}
}
}
#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 *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:kExerciseName ascending:YES];
NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];
[request setSortDescriptors:sortDescriptors];
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];
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
Exercise *exercise = [_fetchedResultsController objectAtIndexPath:indexPath];
UILabel *textLabel = (UILabel *)[[cell contentView] viewWithTag:kExerciseCellTextLabel];
UILabel *detailTextLabel = (UILabel *)[[cell contentView] viewWithTag:kExerciseCellDetailTextLabel];
//UIWebView *miniYouTubeView = (UIWebView *)[[cell contentView] viewWithTag:kExerciseCellMiniYouTubeView];
textLabel.text = [exercise valueForKey:kExerciseName];
detailTextLabel.text = [NSString stringWithFormat:@"%@ - %@", [[exercise valueForKey:kExerciseEType] valueForKey:kExerciseTypeName], [[exercise valueForKey:kGear] valueForKey:kGearName]];
//[textLabel sizeToFit];
//[detailTextLabel sizeToFit];
/*[miniYouTubeView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:[exercise valueForKey:kExerciseUrlAddress]]]];
[miniYouTubeView setScalesPageToFit:YES];
[miniYouTubeView setAutoresizesSubviews:YES];*/
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}