问使用AFNetworking解析JSON时UITableView为空

EN

#import "KKViewController.h"

#import "AFNetworking.h"

#import "AFJSONRequestOperation.h"

@interface KKViewController ()

@end

@implementation KKViewController



- (id)initWithStyle:(UITableViewStyle)style
{
    self = [super initWithStyle:style];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    NSString *urlAsString = @"http://gdata.youtube.com/feeds/api/playlists/PL0l3xlkh7UnvLdr0Zz3XZZuP2tENy_qaP?v=2&alt=jsonc&max-results=50";

    NSURL *url = [NSURL URLWithString:urlAsString];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];


   AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {



       self.videoMetaData = [JSON valueForKeyPath:@"data.items.video"];

      // NSLog(@" video Meta Data %@", self.videoMetaData);





    } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
        NSLog(@"Request Failed with Error: %@, %@", error, error.userInfo);
    }];

    [operation start];


}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{

    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{



  return [self.videoMetaData count];

}



- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *cellID = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellID];

    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:cellID];
    }


    NSDictionary *titles = [self.videoMetaData objectAtIndex:indexPath.row];

    NSLog(@"%@",titles);

    cell.textLabel.text = [titles objectForKey:@"title"];

    return cell;
}