在我的应用程序中，我有两个表格视图。第一张桌子有效。以下是相关方法：
- (void)viewDidLoad
{
NSURL *url = [NSURL URLWithString:@"http://gdata.youtube.com/feeds/api/users/ruflixnet/playlists?v=2&alt=jsonc"];
NSData *jsonData = [NSData dataWithContentsOfURL:url];
NSError *error = nil;
id result = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:&error];
NSLog(@"%@",result);
NSDictionary *objsize = [[NSDictionary alloc] initWithObjectsAndKeys:[[result objectForKey:@"data"] objectForKey:@"totalItems"],@"objsize", nil];
NSString *size = [objsize objectForKey:@"objsize"];
_objects = [[ NSMutableArray alloc] init];
for (int i=1; i<size.integerValue+1; i++) {
NSDictionary * obj1 = [[NSDictionary alloc] initWithObjectsAndKeys:[[[[result objectForKey:@"data"] objectForKey:@"items"] objectAtIndex:i-1] objectForKey:@"title"],@"title",[[[[result objectForKey:@"data"] objectForKey:@"items"] objectAtIndex:i-1] objectForKey:@"id"],@"detail", nil];
[_objects addObject: obj1];}
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return [[self.fetchedResultsController sections] count];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return _objects.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
cell.textLabel.text = [[_objects objectAtIndex:indexPath.row] objectForKey:@"title"];
cell.detailTextLabel.text = [[_objects objectAtIndex:indexPath.row]objectForKey:@"detail"];
return cell;
}
- (NSFetchedResultsController *)fetchedResultsController
{
if (__fetchedResultsController != nil) {
return __fetchedResultsController;
}
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
// Edit the entity name as appropriate.
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Event" inManagedObjectContext:self.managedObjectContext];
[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:@"timeStamp" ascending:NO];
NSArray *sortDescriptors = [NSArray arrayWithObjects:sortDescriptor, nil];
[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:self.managedObjectContext 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)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
NSManagedObject *object = [self.fetchedResultsController objectAtIndexPath:indexPath];
cell.textLabel.text = [[object valueForKey:@"timeStamp"] description];
}
@end
在第二个表格视图中，当我添加 FetchedResultsController 时，表格视图中没有任何单元格。
#import "Videos.h"
#import "DetailViewController.h"
@interface Videos (){
NSMutableArray *_objects2;
}
@end
@implementation Videos
@synthesize detailViewController = _detailViewController;
- (void)viewDidLoad
{
[super viewDidLoad];
NSURL *url = [NSURL URLWithString:@"http://gdata.youtube.com/feeds/api/playlists/A99C8B779B3B098F?v=2&alt=jsonc&max-results=50"];
NSData *jsonData = [NSData dataWithContentsOfURL:url];
NSError *error;
id result = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:&error];
NSLog(@"%@",error);
NSDictionary *objsize = [[NSDictionary alloc] initWithObjectsAndKeys:[[result objectForKey:@"data"] objectForKey:@"totalItems"],@"objsize", nil];
NSString *size = [objsize objectForKey:@"objsize"];
_objects2 = [[ NSMutableArray alloc] init];
for (int i=1; i<size.integerValue+1; i++) {
NSDictionary * obj1 = [[NSDictionary alloc] initWithObjectsAndKeys:[[[[[result objectForKey:@"data"] objectForKey:@"items"] objectAtIndex:1] objectForKey:@"video"] objectForKey:@"title"],@"title",[[[[[result objectForKey:@"data"] objectForKey:@"items"] objectAtIndex:1] objectForKey:@"video"] objectForKey:@"id"],@"detail", nil];
[_objects2 addObject: obj1];} }
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 0;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return _objects2.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *MyIdentifier = @"MyIdentifier";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MyIdentifier] ;
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
}
cell.textLabel.text = [[_objects2 objectAtIndex:indexPath.row] objectForKey:@"title"];
cell.detailTextLabel.text = [[_objects2 objectAtIndex:indexPath.row]objectForKey:@"detail"];
return cell;
}
- (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
cell.textLabel.text = [[_objects2 objectAtIndex:indexPath.row] objectForKey:@"title"];
cell.detailTextLabel.text = [[_objects2 objectAtIndex:indexPath.row]objectForKey:@"detail"]; }
@end