我正在尝试从 Instagram API 获取 JSON，并使用 Xamarin.iOS 将时间轴上的人名放在 UITableView 上。我正在尝试使用 JSON.Net 和 Restsharp 来执行此操作，但是这个问题在过去几周内从未得到解决。以下是我尝试检索数据的方式，问题是出现错误消息:System.InvalidCastexception has been thrown cannot cast from source type to destination type。
除此之外，我如何将特定元素加载到表格中？
我已将其更改为 JObject.Parse(response.content);
现在我收到这个错误:
这是我更新的代码:
client.ExecuteAsync(request, response => {
var array = JObject.Parse(response.Content);
foreach (JObject obj in array)
{
var Name = (string)obj["data"]["user"]["full_name"];
var Caption = (string)obj["data"]["caption"]["text"];
var picURL = (string)obj["data"]["images"]["low_resolution"]["url"];
System.Console.WriteLine("Name of " + Name + ", Caption of " + Caption + ", and picurl of " + picURL);
}
});
这是 JSON 响应:
{
"pagination": {
"next_url": "https://api.instagram.com/v1/users/self/feed?access_token=6489401.88b3fb2.7af2a0355ea24f4590efa1ee82ed0a49&max_id=668439962408115415_16915182",
"next_max_id": "668439962408115415_16915182"
},
"meta": {
"code": 200
},
"data": [
{
"attribution": null,
"tags": [
"selfie"
],
"type": "image",
"location": null,
"comments": {
"count": 0,
"data": []
},
"filter": "Normal",
"created_time": "1393953134",
"link": "http://instagram.com/p/lIO1_jmkkr/",
"likes": {
"count": 14,
"data": [
{
"username": "muahjay",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_304620904_75sq_1392618687.jpg",
"id": "304620904",
"full_name": "Jeanettee Nicole Cambero Gamez"
},
{
"username": "iam_mrsmith31",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_32806209_75sq_1392607367.jpg",
"id": "32806209",
"full_name": "Kiondrix Smith"
},
{
"username": "anniyalation",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_30752906_75sq_1390523572.jpg",
"id": "30752906",
"full_name": "Niya G."
},
{
"username": "fonzo_badmon",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_271402803_75sq_1393641486.jpg",
"id": "271402803",
"full_name": "Slimshady"
}
]
},
"images": {
"low_resolution": {
"url": "http://distilleryimage11.s3.amazonaws.com/e02592b0a3bf11e3b63212d269f676eb_6.jpg",
"width": 306,
"height": 306
},
"thumbnail": {
"url": "http://distilleryimage11.s3.amazonaws.com/e02592b0a3bf11e3b63212d269f676eb_5.jpg",
"width": 150,
"height": 150
},
"standard_resolution": {
"url": "http://distilleryimage11.s3.amazonaws.com/e02592b0a3bf11e3b63212d269f676eb_8.jpg",
"width": 640,
"height": 640
}
},
"users_in_photo": [],
"caption": {
"created_time": "1393953134",
"text": "#Selfie",
"from": {
"username": "kthompkins7",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_5941681_75sq_1378508674.jpg",
"id": "5941681",
"full_name": "kthompkins7"
},
"id": "668849828018145517"
},
"user_has_liked": false,
"id": "668849827690989867_5941681",
"user": {
"username": "kthompkins7",
"website": "",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_5941681_75sq_1378508674.jpg",
"full_name": "kthompkins7",
"bio": "",
"id": "5941681"
}
},
{
"attribution": null,
"tags": [
"rp",
"amen"
],
"type": "image",
"location": null,
"comments": {
"count": 5,
"data": [
{
"created_time": "1393949795",
"text": "@tmcmc Dobson a Christian!!!!",
"from": {
"username": "keelanwillison",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_26089241_75sq_1380511035.jpg",
"id": "26089241",
"full_name": "Keelanwillison"
},
"id": "668821819276579152"
},
{
"created_time": "1393950029",
"text": "Yo my cousin got me a signed autograph from you at the Boston boat show thanks man @a_dobson3",
"from": {
"username": "danthebigboy914",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_27354625_75sq_1393859632.jpg",
"id": "27354625",
"full_name": "Danny Chiappetta"
},
"id": "668823778033324461"
},
{
"created_time": "1393950659",
"text": "Amen",
"from": {
"username": "sandyrodr",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_44889389_75sq_1361591427.jpg",
"id": "44889389",
"full_name": "sandyrodr"
},
"id": "668829062428545715"
},
{
"created_time": "1393950664",
"text": "🙏",
"from": {
"username": "cherydaily",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_18483862_75sq_1379884114.jpg",
"id": "18483862",
"full_name": "Andrew \"Drew\" Chery"
},
"id": "668829109488636596"
},
{
"created_time": "1393951921",
"text": "Amen",
"from": {
"username": "bostonsonia",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_182219303_75sq_1391293289.jpg",
"id": "182219303",
"full_name": "Sonia"
},
"id": "668839648625348773"
}
]
},
"filter": "Normal",
"created_time": "1393949714",
"link": "http://instagram.com/p/lIIUdggtOj/",
"likes": {
"count": 324,
"data": [
{
"username": "bwest05",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_387702554_75sq_1393739891.jpg",
"id": "387702554",
"full_name": "💥bb💥"
},
{
"username": "babygirl6193",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_23365060_75sq_1384972330.jpg",
"id": "23365060",
"full_name": "babygirl6193"
},
{
"username": "derekmooney1",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_218356294_75sq_1388601101.jpg",
"id": "218356294",
"full_name": "Derek Mooney"
},
{
"username": "zay0613",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_342812999_75sq_1369576584.jpg",
"id": "342812999",
"full_name": "Zay"
}
]
},
"images": {
"low_resolution": {
"url": "http://distilleryimage11.s3.amazonaws.com/0e1b270aa3b811e395af12cdc849cb9b_6.jpg",
"width": 306,
"height": 306
},
"thumbnail": {
"url": "http://distilleryimage11.s3.amazonaws.com/0e1b270aa3b811e395af12cdc849cb9b_5.jpg",
"width": 150,
"height": 150
},
"standard_resolution": {
"url": "http://distilleryimage11.s3.amazonaws.com/0e1b270aa3b811e395af12cdc849cb9b_8.jpg",
"width": 640,
"height": 640
}
},
"users_in_photo": [],
"caption": {
"created_time": "1393949714",
"text": "#RP from @flashgoodwin #AMEN",
"from": {
"username": "a_dobson3",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_203045179_75sq_1374262647.jpg",
"id": "203045179",
"full_name": "a_dobson3"
},
"id": "668821135462420769"
},
"user_has_liked": false,
"id": "668821135110099875_203045179",
"user": {
"username": "a_dobson3",
"website": "",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_203045179_75sq_1374262647.jpg",
"full_name": "a_dobson3",
"bio": "",
"id": "203045179"
}
},
{
"attribution": null,
"tags": [
"tb12"
],
"type": "image",
"location": null,
"comments": {
"count": 169,
"data": [
{
"created_time": "1393952642",
"text": "My guy! The greatest! I just want him to get another ring so the haters can stop saying he hasn't won one since 04. I mean he still won them right? #TomBrady @patriots",
"from": {
"username": "k_aus32",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_39840771_75sq_1390431094.jpg",
"id": "39840771",
"full_name": "k_aus32"
},
"id": "668845703585318559"
},
{
"created_time": "1393952673",
"text": "@heres_jonni9",
"from": {
"username": "allyson21lautner",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_184895764_75sq_1393107648.jpg",
"id": "184895764",
"full_name": "Allyson 💌"
},
"id": "668845962264823470"
},
{
"created_time": "1393952694",
"text": "Let's go !",
"from": {
"username": "tom12terrific",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_421023272_75sq_1393644166.jpg",
"id": "421023272",
"full_name": "Andrew Estrada"
},
"id": "668846135581853361"
},
{
"created_time": "1393952856",
"text": "♡",
"from": {
"username": "in_neverland74",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_181245582_75sq_1391928288.jpg",
"id": "181245582",
"full_name": "Karen💕"
},
"id": "668847491935880949"
},
{
"created_time": "1393952914",
"text": "Follow for patriots pics daily!! (Ifollowback)",
"from": {
"username": "ne_patriots_fanpage__",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_983242248_75sq_1391989748.jpg",
"id": "983242248",
"full_name": "New England Patriots Fanpage"
},
"id": "668847980295472912"
},
{
"created_time": "1393952952",
"text": "Best ever; period. Let's see anyone win a ring with the humps he's had to work with, (except Randy).",
"from": {
"username": "calidoso76",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_1101426299_75sq_1392654362.jpg",
"id": "1101426299",
"full_name": "calidoso76"
},
"id": "668848301545604900"
},
{
"created_time": "1393953005",
"text": "Shit just because brady hasn't won a ring since 04 don't mean a thing....one more and he'll have 6.....the most superbowl wins than ANY quarterback EVER. @patriots",
"from": {
"username": "inkandartsosick",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_260242163_75sq_1363337609.jpg",
"id": "260242163",
"full_name": "Eric Hughes"
},
"id": "668848744304723771"
},
{
"created_time": "1393953023",
"text": "👈🏈🙌",
"from": {
"username": "bvsed_papi_",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_408657565_75sq_1393905141.jpg",
"id": "408657565",
"full_name": "Abel Valle™"
},
"id": "668848894913791811"
}
]
},
"filter": "Lo-fi",
"created_time": "1393949267",
"link": "http://instagram.com/p/lIHd-_v8Uj/",
"likes": {
"count": 13685,
"data": [
{
"username": "dollathebarber",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_219503241_75sq_1373905843.jpg",
"id": "219503241",
"full_name": "dollathebarber"
},
{
"username": "emastro23",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_21122956_75sq_1388823730.jpg",
"id": "21122956",
"full_name": "Eddie Mastrocola"
},
{
"username": "pat_fan99",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_304601453_75sq_1377084414.jpg",
"id": "304601453",
"full_name": "Timothy Smith"
},
{
"username": "___adam___q",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_3694047_75sq_1367384028.jpg",
"id": "3694047",
"full_name": "Adam Quinonez"
}
]
},
"images": {
"low_resolution": {
"url": "http://distilleryimage10.s3.amazonaws.com/1c67f514a3b711e383121299eef1f922_6.jpg",
"width": 306,
"height": 306
},
"thumbnail": {
"url": "http://distilleryimage10.s3.amazonaws.com/1c67f514a3b711e383121299eef1f922_5.jpg",
"width": 150,
"height": 150
},
"standard_resolution": {
"url": "http://distilleryimage10.s3.amazonaws.com/1c67f514a3b711e383121299eef1f922_8.jpg",
"width": 640,
"height": 640
}
},
"users_in_photo": [],
"caption": {
"created_time": "1393949267",
"text": "#tb12",
"from": {
"username": "patriots",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_1939080_75sq_1385924433.jpg",
"id": "1939080",
"full_name": "New England Patriots"
},
"id": "668817391815214218"
},
"user_has_liked": false,
"id": "668817391496447267_1939080",
"user": {
"username": "patriots",
"website": "",
"profile_picture": "http://images.ak.instagram.com/profiles/profile_1939080_75sq_1385924433.jpg",
"full_name": "New England Patriots",
"bio": "",
"id": "1939080"
}
},
{
"attribution": null,
"videos": {
"low_resolution": {
"url": "http://distilleryimage4.s3.amazonaws.com/2cb7114aa3b511e3a3e312f545262070_102.mp4",
"width": 480,
"height": 480
},
"standard_resolution": {
"url": "http://distilleryimage4.s3.amazonaws.com/2cb7114aa3b511e3a3e312f545262070_101.mp4",
"width": 640,
"height": 640
}
}
}
]
}
最佳答案
根据您的 JSON 响应(出于验证目的，我已经从 jsonlint.com 更新了它)，似乎 json 数据是对象类型而不是数组类型。因此，在对您的 JSON 响应进行正确分类后，您更新后的代码可能会再次更新如下:
client.ExecuteAsync(request, response =>
{
RootObject rootObject = JsonConvert.DeserializeObject<RootObject>(response.Content);
foreach (Datum obj in rootObject.data)
{
var Name = obj.user.full_name;
var Caption = obj.caption.text;
var picURL = obj.images.low_resolution.url;
System.Console.WriteLine("Name of " + Name + ", Caption of " + Caption + ", and picurl of " + picURL);
}
}
);
您可能从下面的 JSON 响应中派生的类是从 json2csharp.com 生成的
public class RootObject
{
public Pagination pagination { get; set; }
public Meta meta { get; set; }
public List<Datum> data { get; set; }
}
public class Datum
{
public object attribution { get; set; }
public List<string> tags { get; set; }
public string type { get; set; }
public object location { get; set; }
public Comments comments { get; set; }
public string filter { get; set; }
public string created_time { get; set; }
public string link { get; set; }
public Likes likes { get; set; }
public Images images { get; set; }
public List<object> users_in_photo { get; set; }
public Caption caption { get; set; }
public bool user_has_liked { get; set; }
public string id { get; set; }
public User user { get; set; }
public Videos videos { get; set; }
}
public class Videos
{
public LowResolution2 low_resolution { get; set; }
public StandardResolution2 standard_resolution { get; set; }
}
public class StandardResolution2
{
public string url { get; set; }
public int width { get; set; }
public int height { get; set; }
}
public class LowResolution2
{
public string url { get; set; }
public int width { get; set; }
public int height { get; set; }
}
public class User
{
public string username { get; set; }
public string website { get; set; }
public string profile_picture { get; set; }
public string full_name { get; set; }
public string bio { get; set; }
public string id { get; set; }
}
public class Caption
{
public string created_time { get; set; }
public string text { get; set; }
public From from { get; set; }
public string id { get; set; }
}
public class From
{
public string username { get; set; }
public string profile_picture { get; set; }
public string id { get; set; }
public string full_name { get; set; }
}
public class Images
{
public LowResolution low_resolution { get; set; }
public Thumbnail thumbnail { get; set; }
public StandardResolution standard_resolution { get; set; }
}
public class StandardResolution
{
public string url { get; set; }
public int width { get; set; }
public int height { get; set; }
}
public class Thumbnail
{
public string url { get; set; }
public int width { get; set; }
public int height { get; set; }
}
public class LowResolution
{
public string url { get; set; }
public int width { get; set; }
public int height { get; set; }
}
public class Likes
{
public int count { get; set; }
public List<Datum2> data { get; set; }
}
public class Datum2
{
public string username { get; set; }
public string profile_picture { get; set; }
public string id { get; set; }
public string full_name { get; set; }
}
public class Comments
{
public int count { get; set; }
public List<object> data { get; set; }
}
public class Meta
{
public int code { get; set; }
}
public class Pagination
{
public string next_url { get; set; }
public string next_max_id { get; set; }
}
关于c# - 加载 JSON 数据失败，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22162456/