我有一个主人UITableView，程序，点击的每个单元格都会导致与所点击的程序相关的另一个UITableView：剧集。
问题：每次我点击一个程序单元格时，它会将我点击的最后一个程序的剧集追加到剧集表视图控制器中。
示例：假设节目A有剧集i，ii，然后点击剧集A在桌子上显示i，ii 假设节目B有剧集iii，然后点击剧集B显示i，ii，iii而不仅仅是iii
我尝试了什么：我确保每次点击一个programcell时我总是从头开始实例化EpisodesDataSource，每次点击程序单元格时我都会销毁NSFetchedResultsController实例。我也确保我不会多次添加相同的响应描述符..而且我也使用了
[NSFetchedResultsController deleteCacheWithName:@"Master"];
每次我拨打fetchedResultsController ..但仍然没有运气..请参阅下面的实施细节。
在 ProgramsViewController ：
中- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
Controller *controller = [Controller getSingleton];
MediaListViewController *episodesVC =
[controller.storyboard instantiateViewControllerWithIdentifier:@"NewsReportsViewController"];
ProgramCell *programCell = (ProgramCell *)[tableView cellForRowAtIndexPath:indexPath];
episodesVC.dataSource = [[EpisodesDataSource alloc] initWithProgramId:programCell.programId];
[self.navigationController episodesVC animated:YES];
}
在 EpisodesDataSource
中@implementation EpisodesDataSource
- (id)initWithProgramId:(NSNumber *)programId {
self = [self init];
self.programId = programId;
self.parameters = @{@"pid": programId};
self.predicate = @"episode";
return self;
}
- (id)init {
self = [super init];
self.entityName = @"Episodes";
self.resourcePath = kEpisodesPath;
self.sortKey = @"episode_title";
self.keyPath = @"EpisodesList.Episode";
return self;
}
- (void)addResponseDescriptor {
Model *model = [Model getSingleton];
NSArray *existingResponseDescriptors = [model.objectManager.responseDescriptors mapObjectsUsingBlock:^(RKResponseDescriptor *descriptor, NSUInteger idx){
return [descriptor keyPath];
}];
if ([existingResponseDescriptors containsObject:self.keyPath]) {
NSLog(@"response descriptor %@ already exsits! return", self.keyPath);
return;
}
NSLog(@"adding response descriptor %@", self.keyPath);
RKEntityMapping *episodesEntityMapping = [RKEntityMapping mappingForEntityForName:self.entityName inManagedObjectStore:model.managedObjectStore];
// left is http, right is dbase
[episodesEntityMapping addAttributeMappingsFromDictionary:@{@"programId.text": @"episode_id",
@"EpisodeTitle.text": @"episode_title",
@"EpisodeImageUrl.text": @"episode_image_url",
@"EpisodeNewsUrl.text": @"episode_news_url",
@"EpisodeVideoUrl.text": @"episode_video_url",
@"EpisodeVideoId.text": @"episode_video_id",
@"EpisodeCaption.text": @"episode_caption",
@"EpisodeDetails.text": @"episode_details",
}];
episodesEntityMapping.identificationAttributes = @[ @"episode_id" ];
RKResponseDescriptor *episodesResponseDescriptor =
[RKResponseDescriptor responseDescriptorWithMapping:episodesEntityMapping
method:RKRequestMethodAny
pathPattern:self.resourcePath
keyPath:self.keyPath
statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)];
[model.objectManager addResponseDescriptor:episodesResponseDescriptor];
}
并在 MediaListViewController ：
中- (void)viewDidLoad
{
[super viewDidLoad];
// setup delegates
NSAssert(dataSource, @"Datasource of MediaListViewController cannot be nil");
dataSource.tableViewController = self;
self.tableView.dataSource = dataSource;
// setup refresh controller
UIRefreshControl *refreshControl = [UIRefreshControl new];
[refreshControl addTarget:self action:@selector(refreshData) forControlEvents:UIControlEventValueChanged];
self.refreshControl = refreshControl;
// load data
[dataSource addResponseDescriptor];
[dataSource downloadData];
Controller *controller = [Controller getSingleton];
UIView *background = [[UIView alloc] initWithFrame:controller.window.frame];
[background setBackgroundColor:[UIColor redColor]];
[background setTag:999];
[[self.tableView superview] addSubview:background];
[[self.tableView superview] sendSubviewToBack:background];
}
EpisodesDataSource 继承自 DataSource：，其中包含：
- (NSFetchedResultsController *)fetchedResultsController
{
// reset
[NSFetchedResultsController deleteCacheWithName:@"Master"];
if (_fetchedResultsController != nil) {
return _fetchedResultsController;
}
NSManagedObjectContext *context =((Model *)[Model getSingleton]).managedObjectStore.mainQueueManagedObjectContext;
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:self.entityName
inManagedObjectContext:context];
[fetchRequest setEntity:entity];
// Set the batch size to a suitable number.
[fetchRequest setFetchBatchSize:20];
// Edit the sort key as appropriate.
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:self.sortKey ascending:NO];
NSArray *sortDescriptors = @[sortDescriptor];
[fetchRequest setSortDescriptors:sortDescriptors];
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
NSFetchedResultsController *aFetchedResultsController
= [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:context
sectionNameKeyPath:nil
cacheName:@"Master"];
aFetchedResultsController.delegate = self;
self.fetchedResultsController = aFetchedResultsController;
NSError *error = nil;
if (![self.fetchedResultsController performFetch:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
return _fetchedResultsController;
}
- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
[tableViewController.tableView beginUpdates];
}
- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
[tableViewController.tableView endUpdates];
}
答案 0 :(得分：1)
根据@Duncan Groenewald的评论，您应该使用谓词来过滤掉数据存储的内容，这样您才能显示子集。目前，您每次处理新下载时都会显示所有内容，您将获得其他表格视图内容。
对于后续问题，请检查谓词。当您期望匹配时（即将字符串“100”与数字100进行比较），托管对象和谓词中使用的类/数据类型不匹配可能会导致失败。
通常，托管对象中的所有相同类型的信息都应该与数据类型匹配，并且当从主接口移动到详细接口时，您应该传递托管对象（或来自托管对象的值）以确保您保持一致性提取/过滤时。