使用JSON在表视图中加载数据时,应用程序崩溃

Question

我正在表视图中加载JSON数据.问题是,如果我滚动表视图,我的应用程序崩溃.以下是代码:

    - (void)viewDidLoad {
    [super viewDidLoad];
    jsonurl=[NSURL URLWithString:@"http://www.1040communications.net/sheeba/stepheni/iphone/stephen.json"];

    jsonData=[[NSString alloc]initWithContentsOfURL:jsonurl];

    jsonArray = [jsonData JSONValue]; 


    items = [jsonArray objectForKey:@"items"];

    story = [NSMutableArray array];
    description1 = [NSMutableArray array];
    media1 = [NSMutableArray array];

    for (NSDictionary *item in items )
    {
        [story addObject:[item objectForKey:@"title"]];
        [media1 addObject:[item objectForKey:@"media"]];


    }
     NSLog(@"booom:%@",story);

}

    - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

    - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [story count];
}


// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewStyleGrouped reuseIdentifier:CellIdentifier] autorelease];
    }

    cell.textLabel.text=[story objectAtIndex:indexPath.row];
    cell.detailTextLabel.text=[media1 objectAtIndex:indexPath.row];
    return cell;
}

Answer 1

您必须保留数组,因为您将它们分配给实例变量:

story = [[NSMutableArray array] retain];
description1 = [[NSMutableArray array] retain];
media1 = [[NSMutableArray array] retain];

如果您在以下情况下需要它们,您还必须保留这些实例变量viewDidLoad:

jsonurl
jsonArray
items