Question

以下是来自PHP网页的编码JSON数据。

{
    {
        "news_date" = "2011-11-09";
        "news_id" = 5;
        "news_imageName" = "newsImage_111110_7633.jpg";
        "news_thread" = "test1";
        "news_title" = "test1 Title";
    },
    {
        "news_date" = "2011-11-10";
        "news_id" = 12;
        "news_imageName" = "newsImage_111110_2060.jpg";
        "news_thread" = "thread2";
        "news_title" = "title2";
    },
// and so on...
}

我想获取一个信息（日期/ id /图像/线程/标题），并将其存储为类的实例。但是，我不知道如何访问2D数组中的每个对象。以下是我编写的代码，用于测试我是否可以访问它们，但它不起作用。

会出现什么问题？

NSURL *jsonURL = [NSURL URLWithString:@"http://www.sangminkim.com/UBCKISS/category/news/jsonNews.php"];
NSString *jsonData = [[NSString alloc] initWithContentsOfURL:jsonURL];
SBJsonParser *parser = [[SBJsonParser alloc] init];
contentArray = [parser objectWithString:jsonData];
NSLog(@"array: %@", [[contentArray objectAtIndex:0] objectAtIndex:0]); // CRASH!!

Answer 1

在JSON术语中，这不是一个二维数组：它是一个数组，其元素是对象。在Cocoa术语中，它是一个数组，其元素是字典。

您可以这样阅读：

NSArray *newsArray = [parser objectWithString:jsonData];

for (NSDictionary *newsItem in newsArray) {
    NSString *newsDate = [newsItem objectForKey:@"news_date"];
    NSUInteger newsId = [[newsItem objectForKey:@"news_id"] integerValue];
    NSString *newsImageName = [newsItem objectForKey:@"news_imageName"];
    NSString *newsThread = [newsItem objectForKey:@"news_thread"];
    NSString *newsTitle = [newsItem objectForKey:@"news_title"];

    // Do something with the data above
}

Answer 2

你给了我一个机会来检查iOS 5 Native JSON解析器，所以不需要外部库，试试这个：

-(void)testJson
{
  NSURL *jsonURL = [NSURL URLWithString:@"http://www.sangminkim.com/UBCKISS/category/news/jsonNews.php"];
  NSData *jsonData = [NSData dataWithContentsOfURL:jsonURL];

  NSError* error;
  NSArray* json = [NSJSONSerialization 
                      JSONObjectWithData:jsonData //1

                      options:kNilOptions 
                      error:&error];

  NSLog(@"First Dictionary: %@", [json objectAtIndex:0]);
  //Log output:
  //    First Dictionary: {
  //        "news_date" = "2011-11-09";
  //        "news_id" = 5;
  //        "news_imageName" = "newsImage_111110_7633.jpg";
  //        "news_thread" = " \Uc774\Uc81c \Uc571 \Uac1c\Ubc1c \Uc2dc\Uc791\Ud574\Ub3c4 \Ub420\Uac70 \Uac19\Uc740\Ub370? ";
  //        "news_title" = "\Ub418\Ub294\Uac70 \Uac19\Uc9c0?";
  //    }

  //Each item parsed is an NSDictionary
  NSDictionary* item1 = [json objectAtIndex:0];
  NSLog(@"Item1.news_date= %@", [item1 objectForKey:@"news_date"]);
  //Log output: Item1.news_date= 2011-11-09
}

JSON和2D数组

2 个答案: