Ios 无法在FourSquare API中访问NSDictionary密钥

我正在尝试访问以下FourSquare NSDictionary中的前缀和后缀字符串。在我的nsobject中，我尝试了以下方法，但没有成功。有没有一种简单的方法来访问字符串？我试过：

venue.photo = v[@"photo"];
venue.photo = v[@"photo"][@"prefix"];

词典会打印：

{
    categories =     (
                {
            icon =             {
                prefix = "https://ss3.4sqi.net/img/categories_v2/arts_entertainment/movietheater_";
                suffix = ".png";
            };
            id = 4bf58dd8d48988d17f941735;
            name = "Movie Theater";
            pluralName = "Movie Theaters";
            primary = 1;
            shortName = "Movie Theater";
        }
    );
    contact =     {
        formattedPhone = "(844) 462-7342";
        phone = 8444627342;
        twitter = regalmovies;
    };
    events =     {
        count = 9;
        summary = "9 movies";
    };
    hasMenu = 1;
    hereNow =     {
        count = 2;
        groups =         (
                        {
                count = 2;
                items =                 (
                );
                name = "Other people here";
                type = others;
            }
        );
        summary = "2 people are checked in here";
    };
    id = 4a2aac37f964a52034961fe3;
    location =     {
        address = "1471 W Webster Ave";
        cc = US;
        city = Chicago;
        country = "United States";
        formattedAddress =         (
            "1471 W Webster Ave",
            "Chicago, IL 60614",
            "United States"
        );
        lat = "41.92149057";
        lng = "-87.66487751";
        postalCode = 60614;
        state = IL;
    };
    menu =     {
        anchor = "View Menu";
        label = Menu;
        mobileUrl = "https://foursquare.com/v/4a2aac37f964a52034961fe3/device_menu";
        type = Menu;
        url = "https://foursquare.com/v/regal-webster-place-11/4a2aac37f964a52034961fe3/menu";
    };
    name = "Regal Webster Place 11";
    referralId = "v-1416373439";
    specials =     {
        count = 1;
        items =         (
                        {
                description = "";
                icon = default;
                id = 50355f96d86cbef3478adc65;
                interaction =                 {
                    entryUrl = "https://foursquare.com/device/specials/50355f96d86cbef3478adc65?venueId=4a2aac37f964a52034961fe3";
                };
                message = "Join us for Deal Days! ALL DAY Tuesday enjoy $6.50 tickets.";
                page =                 {
                    bio = "";
                    contact =                     {
                        twitter = regalmovies;
                    };
                    firstName = "Regal Cinemas";
                    followers =                     {
                        count = 12203;
                        groups =                         (
                        );
                    };
                    gender = none;
                    homeCity = "Knoxville, TN";
                    id = 12864010;
                    photo =                     {
                        prefix = "https://irs0.4sqi.net/img/user/";
                        suffix = "/DMGZGZVXT3NVLKNP.jpg";
                    };
                    tips =                     {
                        count = 347;
                    };
                    type = chain;
                };
                provider = foursquare;
                redemption = webview;
                state = unlocked;
                title = Special;
                type = frequency;
                unlocked = 1;
            }
        );
    };
    stats =     {
        checkinsCount = 23578;
        tipCount = 56;
        usersCount = 10220;
    };
    storeId = Chicago;
    verified = 1;
}

---

下面的代码应该可以工作-

NSArray *itemsArray=(NSArray *)venue[@"items"];
for (NSDictionary *specialDictionary in itemsArray) {
    NSDictionary *pageDictionary=(NSDictionary *)specialDictionary[@"page"];
    NSDictionary *photoDictionary=(NSDictionary *)pageDictionary[@"photo"];
    NSString *prefix=(NSString *)photoDictionary[@"prefix"];
    NSString *suffix=(NSString *)photoDictionary[@"suffix"];
    // Do something with prefix and suffix 
}

---

请注意，关键项目中有一个小括号，这一行

items =         ( <----
                        {
                description = "";
                icon = default;
                id = 50355f96d86cbef3478adc65;
                interaction =                 {

---

首先，您打印的是字典，而不是数组。这个字典似乎有items的值，在本例中，items是一个包含一个元素的字典数组。items数组中的第一个字典具有密钥页的字典。页面字典包含一个关键图片字典，其中包含关键前缀字符串和后缀，用于指出我仍在学习。我更新了问题并使用了：vitune.photo=v[@specials][@items][@page][@photo][@prefix]；但没有运气。我尝试了一下，但出现了错误：“NSRangeException”，原因：“***-[\uu NSArrayI objectAtIndex:]：索引0超出空数组的界限”您可以先检查项目的大小NSLog@size：%d，v[@specials][@items]。大小；猜测items数组有时可能是空的？？谢谢，但我得到了错误“读取字典元素的预期方法在“FSVenue”类型的对象上找不到”。在研究之后，我是否要在我的“FSVenue”对象中添加objectforkeydsubscript:？哪个对象是FSVenue？看起来你没有一本普通的词典，但你正在使用一些库？你正在使用的图书馆的URL是什么。它是FourSquare场馆/搜索API-。这就是您所指的吗？不，错误消息中显示的是什么类型的对象？它似乎是一个FSVenue，而不是您将从JSONParser返回的普通NSDictionary。您是否正在使用某个框架或库与API进行交互？您是对的，地点是FSVINCE，对此感到困惑，深表歉意。我使用的是Constantine的github，如果这回答了您的URL问题，那么调用将使用NSURLRequest。

 venue.photo = v[@"specials"][@"items"][0][@"page"][@"photo"][@"prefix"];