我正在尝试将Json文件解析为Table视图,我收到此错误
[__ NSCFDictionary objectAtIndex:]:无法识别的选择器发送到实例 而应用程序正在崩溃。请帮帮我,我是iOS开发的新手。
我的代码
@implementation ViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
self.title = @"Feeds";
[super viewDidLoad];
[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
NSURL *url = [NSURL URLWithString:@"http://little-people.blogspot.com/feeds/posts /default?alt=json"];
NSURLRequest *request = [NSURLRequest requestWithURL:url];
[[NSURLConnection alloc] initWithRequest:request delegate:self];
}
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
data = [[NSMutableData alloc] init];
NSLog(@"Data Data , %@", data);
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)theData
{
[data appendData:theData];
}
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
feed = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
NSLog(@"Data , %@", feed);
[mainTableView reloadData];
}
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
UIAlertView *errorView = [[UIAlertView alloc] initWithTitle:@"Error" message:@"The download could not complete - please make sure you're connected to either 3G or Wi-Fi." delegate:nil cancelButtonTitle:@"Dismiss" otherButtonTitles:nil];
[errorView show];
[UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
}
- (int)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (int)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [feed count];
NSLog(@"Data Data , %@", feed);
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"MainCell"];
if(cell == nil){
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:@"MainCell"];
}
if (([feed count] - 1) >=indexPath.row) {
cell.textLabel.text = [[feed objectAtIndex:indexPath.row] objectForKey:@"feed"];
cell.detailTextLabel.text = [[feed objectAtIndex:indexPath.row] objectForKey:@"title"];
}
return cell;
}
答案 0 :(得分:8)
问题是feed
不是NSArray
,而是NSDictionary
。
查看JSON,您可能想要访问此数组:[feed objectForKey:@"entry"]
答案 1 :(得分:3)
Feed中的顶级对象是JSON对象,而不是JSON数组。因此,反序列化为您提供了NSDictionary,而不是NSArray。