Iphone 计算JSON项的xcode

我需要计算这个JSON响应中的项目（post）数量

2012-06-04 14:09:57.872 horitable[72261:11903] JSON : {
posts =     (
            {
        post =             {
            eventdate = "2012-03-31";
            eventid = 2;
            eventimage = "http://hernandoz.local/~hernandoz/kopict/02_31march2012.jpg";
            eventinfo = "02 event";
            eventname = "xplosion 02";
        };
    },
            {
        post =             {
            eventdate = "2012-07-07";
            eventid = 3;
            eventimage = "http://hernandoz.local/~hernandoz/kopict/greg_vs_turner.jpg";
            eventinfo = "02 event";
            eventname = "Xplosion 02";
        };
    },
            {
        post =             {
            eventdate = "2012-04-29";
            eventid = 4;
            eventimage = "http://hernandoz.local/~hernandoz/kopict/ko_itclub_apr_2012.jpg";
            eventinfo = "KO East London Interclub";
            eventname = "KO Interclub";
        };
    }
);

}

我知道只有3个事件（post），这是我正在使用的代码

 [[AFNetworkActivityIndicatorManager sharedManager] decrementActivityCount];
    NSLog(@"JSON : %@", JSON); //get the JSON response

    // 6.1 - Load JSON into internal variable
    jsonResponse = JSON;
    // 6.2 - Get the number of shows (post)
    int shows = 0;
    for (NSDictionary* day in jsonResponse) {
        shows += [[day objectForKey:@"posts"] count];

        NSLog(@"count : %d",shows);
    }

我有一个错误，但我不明白为什么

-[__NSCFString objectForKey:]: unrecognized selector sent to instance 0x76986f0

---

谁能帮帮我吗。谢谢

在您的情况下，您可以这样做

 [[AFNetworkActivityIndicatorManager sharedManager] decrementActivityCount];
 NSLog(@"JSON : %@", JSON); //get the JSON response

// 6.1 - Load JSON into internal variable
jsonResponse = JSON;
// 6.2 - Get the number of shows (post)
int shows = [[jsonResponse objectForKey:@"posts"] count];

   NSLog(@"count : %d",shows);

---

您需要首先将json分解为

NSDictionary * dict = [JSON JSONValue];

或

然后

试试这个

NSLog(@"Response members= %@",responseString);
NSArray *array = [(NSDictionary*)[responseString JSONValue] objectForKey:@"posts"];
NSLog(@"Count value= %d",[array count]);    

---

问题是JSON作为一个ID，这是可行的

---

jsonResponse=[（NSDictionary*）JSON objectForKey:@“posts”]
我认为你把“post”改为“post”是错误的。键“posts”包含一个字典数组，每个字典都有一个键“post”。您所做的是从数组中以行的形式获取所有字典

  for (NSDictionary* day in jsonResponse) {

并检查字典中的关键“帖子”。实际上，字典里并没有所谓的“posts”键。我是“波斯特”。“post”的值是NSDictionary而不是数组。所以你不能在那里叫
count
。您的问题的解决方案是删除for循环中不必要的API

  [[AFNetworkActivityIndicatorManager sharedManager] decrementActivityCount];
  jsonResponse = JSON;

  int shows = 0;
  for (NSDictionary* day in jsonResponse) {
      shows += 1;
  }

  NSLog(@"count : %d",shows);

只是想确保您已正确分配NSDictionaryjsonResponse为NSArray且JSON为IDI获取错误-NSArray没有可见的@interface声明选择器“objectforkey”objectforkey不是objectforkey是的，这是我键入错误的方式，但如果您执行NSLog（@“jsonResponse:%@”，jsonResponse），则在Xcode中是objectforkey；我在JSON responseHi得到了同样的结果，那JSONValue是什么？我没有使用任何外部库，只有AFJSIT是JSon库的函数，用于将JSon数据转换为字典或数组。下载sbjson并使用它。
  for (NSDictionary* day in jsonResponse) {

  [[AFNetworkActivityIndicatorManager sharedManager] decrementActivityCount];
  jsonResponse = JSON;

  int shows = 0;
  for (NSDictionary* day in jsonResponse) {
      shows += 1;
  }

  NSLog(@"count : %d",shows);