通过反序列化json对象我遇到了问题
明确地说：http://store.steampowered.com/api/appdetails?appids=730
我收到以下错误：以下代码的System.NullReferenceException：
string json = new WebClient().DownloadString("http://store.steampowered.com/api/appdetails?appids=730");
更多信息：
无法将当前JSON对象（例如{“name”：“value”}）反序列化为类型'System.Collections.Generic.List`1 [Steam.Program + RootObject]'，因为该类型需要JSON数组（例如[1,2,3]）正确反序列化。要修复此错误，请将JSON更改为JSON数组（例如[1,2,3]）或更改反序列化类型，使其成为普通的.NET类型（例如，不是像整数这样的基本类型，而不是类似的集合类型可以从JSON对象反序列化的数组或List。 JsonObjectAttribute也可以添加到类型中以强制它从JSON对象反序列化。
但我认为这是Visual Studio的一个错误。
类：
public class PcRequirements
{
public string minimum { get; set; }
}
public class MacRequirements
{
public string minimum { get; set; }
}
public class LinuxRequirements
{
public string minimum { get; set; }
}
public class PriceOverview
{
public string currency { get; set; }
public int initial { get; set; }
public int final { get; set; }
public int discount_percent { get; set; }
}
public class Sub
{
public int packageid { get; set; }
public string percent_savings_text { get; set; }
public int percent_savings { get; set; }
public string option_text { get; set; }
public string option_description { get; set; }
public string can_get_free_license { get; set; }
public bool is_free_license { get; set; }
public int price_in_cents_with_discount { get; set; }
}
public class PackageGroup
{
public string name { get; set; }
public string title { get; set; }
public string description { get; set; }
public string selection_text { get; set; }
public string save_text { get; set; }
public int display_type { get; set; }
public string is_recurring_subscription { get; set; }
public List<Sub> subs { get; set; }
}
public class Platforms
{
public bool windows { get; set; }
public bool mac { get; set; }
public bool linux { get; set; }
}
public class Metacritic
{
public int score { get; set; }
public string url { get; set; }
}
public class Category
{
public int id { get; set; }
public string description { get; set; }
}
public class Genre
{
public string id { get; set; }
public string description { get; set; }
}
public class Screenshot
{
public int id { get; set; }
public string path_thumbnail { get; set; }
public string path_full { get; set; }
}
public class Webm
{
public string __invalid_name__480 { get; set; }
public string max { get; set; }
}
public class Movie
{
public int id { get; set; }
public string name { get; set; }
public string thumbnail { get; set; }
public Webm webm { get; set; }
public bool highlight { get; set; }
}
public class Recommendations
{
public int total { get; set; }
}
public class Highlighted
{
public string name { get; set; }
public string path { get; set; }
}
public class Achievements
{
public int total { get; set; }
public List<Highlighted> highlighted { get; set; }
}
public class ReleaseDate
{
public bool coming_soon { get; set; }
public string date { get; set; }
}
public class SupportInfo
{
public string url { get; set; }
public string email { get; set; }
}
public class Data
{
public string type { get; set; }
public string name { get; set; }
public int steam_appid { get; set; }
public int required_age { get; set; }
public bool is_free { get; set; }
public string controller_support { get; set; }
public string detailed_description { get; set; }
public string about_the_game { get; set; }
public string supported_languages { get; set; }
public string header_image { get; set; }
public string website { get; set; }
public PcRequirements pc_requirements { get; set; }
public MacRequirements mac_requirements { get; set; }
public LinuxRequirements linux_requirements { get; set; }
public List<string> developers { get; set; }
public List<string> publishers { get; set; }
public PriceOverview price_overview { get; set; }
public List<int> packages { get; set; }
public List<PackageGroup> package_groups { get; set; }
public Platforms platforms { get; set; }
public Metacritic metacritic { get; set; }
public List<Category> categories { get; set; }
public List<Genre> genres { get; set; }
public List<Screenshot> screenshots { get; set; }
public List<Movie> movies { get; set; }
public Recommendations recommendations { get; set; }
public Achievements achievements { get; set; }
public ReleaseDate release_date { get; set; }
public SupportInfo support_info { get; set; }
public string background { get; set; }
}
public class steamstore
{
public bool success { get; set; }
public Data data { get; set; }
}
public class RootObject
{
public steamstore steamstore { get; set; }
}
主：
static void Main(string[] args)
{
string json = new WebClient().DownloadString("http://store.steampowered.com/api/appdetails?appids=730");
var root = JsonConvert.DeserializeObject<RootObject>(json);
Console.WriteLine(root.steamstore.data.name);
Console.ReadKey();
}
无法将当前JSON对象（例如{“name”：“value”}）反序列化为类型'System.Collections.Generic.List`1 [Steam.Program + RootObject]'，因为该类型需要JSON数组（例如[1,2,3]）正确反序列化。要修复此错误，请将JSON更改为JSON数组（例如[1,2,3]）或更改反序列化类型，使其成为普通的.NET类型（例如，不是像整数这样的基本类型，而不是类似的集合类型可以从JSON对象反序列化的数组或List。 JsonObjectAttribute也可以添加到类型中以强制它从JSON对象反序列化。
答案 0 :(得分：4)
那是因为json不匹配
提取730对象，然后将其解析为已定义的类
public static void Main()
{
string json = new WebClient().DownloadString("http://store.steampowered.com/api/appdetails?appids=730");
JObject jObject = JObject.Parse(json);
var root = jObject["730"].Value<JObject>().ToObject<steamstore>();
Console.WriteLine(root.data.name);
Console.ReadKey();
}
这是来自http://store.steampowered.com/api/appdetails?appids=730
的Json{"730":{"success":true,"data":{"type":"game","name":"Counter-Strike: Global Offensive","steam_appid":730,"required_age":0,"is_free":false,"controller_support":"full","detailed_description":"Counter-Strike: Global Offensive (CS: GO) will expand upon the team-based action gameplay that it pioneered when it was launched 14 years ago.<br \/>\r\n<br \/>\r\nCS: GO features new maps, characters, and weapons and delivers updated versions of the classic CS content (de_dust, etc.). In addition, CS: GO will introduce new gameplay modes, matchmaking, leader boards, and more.<br \/>\r\n<br \/>\r\n"Counter-Strike took the gaming industry by surprise when the unlikely MOD became the most played online PC action game in the world almost immediately after its release in August 1999," said Doug Lombardi at Valve. "For the past 12 years, it has continued to be one of the most-played games in the world, headline competitive gaming tournaments and selling over 25 million units worldwide across the franchise. CS: GO promises to expand on CS' award-winning gameplay and deliver it to gamers on the PC as well as the next gen consoles and the Mac."","about_the_game":"Counter-Strike: Global Offensive (CS: GO) will expand upon the team-based action gameplay that it pioneered when it was launched 14 years ago.<br \/>\r\n<br \/>\r\nCS: GO features new maps, characters, and weapons and delivers updated versions of the classic CS content (de_dust, etc.). In addition, CS: GO will introduce new gameplay modes, matchmaking, leader boards, and more.<br \/>\r\n<br \/>\r\n"Counter-Strike took the gaming industry by surprise when the unlikely MOD became the most played online PC action game in the world almost immediately after its release in August 1999," said Doug Lombardi at Valve. "For the past 12 years, it has continued to be one of the most-played games in the world, headline competitive gaming tournaments and selling over 25 million units worldwide across the franchise. CS: GO promises to expand on CS' award-winning gameplay and deliver it to gamers on the PC as well as the next gen consoles and the Mac."","supported_languages":"Czech, Danish, Dutch, English<strong>*<\/strong>, Finnish, French, German, Hungarian, Italian, Japanese, Korean, Norwegian, Polish, Portuguese, Portuguese-Brazil, Romanian, Russian, Simplified Chinese, Spanish, Swedish, Thai, Traditional Chinese, Turkish, Bulgarian, Ukrainian<br><strong>*<\/strong>languages with full audio support","header_image":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/header.jpg?t=1467065027","website":"http:\/\/blog.counter-strike.net\/","pc_requirements":{"minimum":"<strong>Minimum:<\/strong>\r<br><ul class=\"bb_ul\"><li><strong>OS:<\/strong> Windows\u00ae 7\/Vista\/XP\r<br><\/li><li><strong>Processor:<\/strong> Intel\u00ae Core\u2122 2 Duo E6600 or AMD Phenom\u2122 X3 8750 processor or better\r<br><\/li><li><strong>Memory:<\/strong> 2 GB RAM\r<br><\/li><li><strong>Graphics:<\/strong> Video card must be 256 MB or more and should be a DirectX 9-compatible with support for Pixel Shader 3.0\r<br><\/li><li><strong>DirectX:<\/strong> Version 9.0c\r<br><\/li><li><strong>Storage:<\/strong> 8 GB available space\r<\/li><\/ul>"},"mac_requirements":{"minimum":"<strong>Minimum:<\/strong>\r<br><ul class=\"bb_ul\"><li><strong>OS:<\/strong> MacOS X 10.6.6 or higher\r<br><\/li><li><strong>Processor:<\/strong> Intel Core Duo Processor (2GHz or better)\r<br><\/li><li><strong>Memory:<\/strong> 2 GB RAM\r<br><\/li><li><strong>Graphics:<\/strong> ATI Radeon HD 2400 or better \/ NVidia 8600M or better\r<br><\/li><li><strong>Storage:<\/strong> 8 GB available space\r<\/li><\/ul>"},"linux_requirements":{"minimum":"<strong>Minimum:<\/strong>\r<br><ul class=\"bb_ul\"><li><strong>OS:<\/strong> Ubuntu 12.04\r<br><\/li><li><strong>Processor:<\/strong> 64-bit Dual core from Intel or AMD at 2.8 GHz\r<br><\/li><li><strong>Memory:<\/strong> 4 GB RAM\r<br><\/li><li><strong>Graphics:<\/strong> nVidia GeForce 8600\/9600GT, ATI\/AMD Radeon HD2600\/3600 (Graphic Drivers: nVidia 310, AMD 12.11), OpenGL 2.1\r<br><\/li><li><strong>Storage:<\/strong> 8 GB available space\r<br><\/li><li><strong>Sound Card:<\/strong> OpenAL Compatible Sound Card\r<\/li><\/ul>"},"developers":["Valve"],"publishers":["Valve"],"price_overview":{"currency":"SGD","initial":1500,"final":1500,"discount_percent":0},"packages":[54029],"package_groups":[{"name":"default","title":"Buy Counter-Strike: Global Offensive","description":"","selection_text":"Select a purchase option","save_text":"","display_type":0,"is_recurring_subscription":"false","subs":[{"packageid":54029,"percent_savings_text":"","percent_savings":0,"option_text":"Counter-Strike: Global Offensive - S$15.00","option_description":"","can_get_free_license":"0","is_free_license":false,"price_in_cents_with_discount":1500}]}],"platforms":{"windows":true,"mac":true,"linux":true},"metacritic":{"score":83,"url":"http:\/\/www.metacritic.com\/game\/pc\/counter-strike-global-offensive?ftag=MCD-06-10aaa1f"},"categories":[{"id":1,"description":"Multi-player"},{"id":22,"description":"Steam Achievements"},{"id":28,"description":"Full controller support"},{"id":29,"description":"Steam Trading Cards"},{"id":30,"description":"Steam Workshop"},{"id":35,"description":"In-App Purchases"},{"id":8,"description":"Valve Anti-Cheat enabled"},{"id":15,"description":"Stats"}],"genres":[{"id":"1","description":"Action"}],"screenshots":[{"id":0,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_34090867f1a02b6c17652ba9043e3f622ed985a9.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_34090867f1a02b6c17652ba9043e3f622ed985a9.1920x1080.jpg?t=1467065027"},{"id":1,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_1d30c9a215fd621e2fd74f40d93b71587bf6409c.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_1d30c9a215fd621e2fd74f40d93b71587bf6409c.1920x1080.jpg?t=1467065027"},{"id":2,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_baa02e979cd3852e3c4182afcd603ab64e3502f9.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_baa02e979cd3852e3c4182afcd603ab64e3502f9.1920x1080.jpg?t=1467065027"},{"id":3,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_ffe584c163a2b16e9c1b733b1c8e2ba669fb1204.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_ffe584c163a2b16e9c1b733b1c8e2ba669fb1204.1920x1080.jpg?t=1467065027"},{"id":4,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_d87c102d028d545c877363166c9d8377014f0c23.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_d87c102d028d545c877363166c9d8377014f0c23.1920x1080.jpg?t=1467065027"},{"id":5,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_9d0735a5fbe523fd39f2c69c047019843c326cea.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_9d0735a5fbe523fd39f2c69c047019843c326cea.1920x1080.jpg?t=1467065027"},{"id":6,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_9d889bec419cf38910ccf72dd80f9260227408ee.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_9d889bec419cf38910ccf72dd80f9260227408ee.1920x1080.jpg?t=1467065027"},{"id":7,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_ccc4ce6edd4c454b6ce7b0757e633b63aa93921d.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_ccc4ce6edd4c454b6ce7b0757e633b63aa93921d.1920x1080.jpg?t=1467065027"},{"id":8,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_9db552fd461722f1569e3292d8f2ea654c8ffdef.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_9db552fd461722f1569e3292d8f2ea654c8ffdef.1920x1080.jpg?t=1467065027"},{"id":9,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_74c1a0264ceaf57e5fb51d978205045223b48a18.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_74c1a0264ceaf57e5fb51d978205045223b48a18.1920x1080.jpg?t=1467065027"},{"id":10,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_7eaa83e44f5218a7bf5f88a0c750e36052e31d7d.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_7eaa83e44f5218a7bf5f88a0c750e36052e31d7d.1920x1080.jpg?t=1467065027"},{"id":11,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_68007896ad6071b7062bac530c481e097105efc0.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_68007896ad6071b7062bac530c481e097105efc0.1920x1080.jpg?t=1467065027"},{"id":12,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_2fcee01bace72bc47a2ad0ba82620588239e93df.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_2fcee01bace72bc47a2ad0ba82620588239e93df.1920x1080.jpg?t=1467065027"},{"id":13,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_f5875f8de419a3d5133ae7245b8296db2c027dd8.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_f5875f8de419a3d5133ae7245b8296db2c027dd8.1920x1080.jpg?t=1467065027"},{"id":14,"path_thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_36f82c71ee2180159b060b155bf3d06dd8167327.600x338.jpg?t=1467065027","path_full":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/ss_36f82c71ee2180159b060b155bf3d06dd8167327.1920x1080.jpg?t=1467065027"}],"movies":[{"id":81958,"name":"CS:GO Trailer Long","thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/81958\/movie.293x165.jpg?t=1459467902","webm":{"480":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/81958\/movie480.webm?t=1459467902","max":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/81958\/movie_max.webm?t=1459467902"},"highlight":true},{"id":2028288,"name":"CS: GO Pro Tip Series: TM","thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028288\/movie.293x165.jpg?t=1459467945","webm":{"480":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028288\/movie480.webm?t=1459467945","max":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028288\/movie_max.webm?t=1459467945"},"highlight":false},{"id":2028287,"name":"CS: GO Pro Tip Series: sapphiRe","thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028287\/movie.293x165.jpg?t=1459467936","webm":{"480":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028287\/movie480.webm?t=1459467936","max":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028287\/movie_max.webm?t=1459467936"},"highlight":false},{"id":2028286,"name":"CS: GO Pro Tip Series: AZK","thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028286\/movie.293x165.jpg?t=1459467927","webm":{"480":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028286\/movie480.webm?t=1459467927","max":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028286\/movie_max.webm?t=1459467927"},"highlight":false},{"id":2028285,"name":"CS: GO Pro Tip Series: Fifflaren","thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028285\/movie.293x165.jpg?t=1459467962","webm":{"480":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028285\/movie480.webm?t=1459467962","max":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028285\/movie_max.webm?t=1459467962"},"highlight":false},{"id":2028284,"name":"CS: GO Pro Tip Series: ruggah","thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028284\/movie.293x165.jpg?t=1459467919","webm":{"480":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028284\/movie480.webm?t=1459467919","max":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028284\/movie_max.webm?t=1459467919"},"highlight":false},{"id":2028283,"name":"CS: GO Pro Tip Series: nEiLZiNHo","thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028283\/movie.293x165.jpg?t=1459467911","webm":{"480":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028283\/movie480.webm?t=1459467911","max":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028283\/movie_max.webm?t=1459467911"},"highlight":false},{"id":2028289,"name":"CS: GO Pro Tip Series: Semphis","thumbnail":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028289\/movie.jpg?t=1459467954","webm":{"480":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028289\/movie480.webm?t=1459467954","max":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/2028289\/movie_max.webm?t=1459467954"},"highlight":false}],"recommendations":{"total":1385472},"achievements":{"total":167,"highlighted":[{"name":"Someone Set Up Us The Bomb","path":"http:\/\/cdn.akamai.steamstatic.com\/steamcommunity\/public\/images\/apps\/730\/9f60ea3c56b4ab248ab598bbd62568b953116301.jpg"},{"name":"Boomala Boomala","path":"http:\/\/cdn.akamai.steamstatic.com\/steamcommunity\/public\/images\/apps\/730\/325ccbd68e599083c1597fd90dc6d4265d1ca3b4.jpg"},{"name":"The Hurt Blocker","path":"http:\/\/cdn.akamai.steamstatic.com\/steamcommunity\/public\/images\/apps\/730\/9b8627953feca51a56f0c2ac871493c8634a1c07.jpg"},{"name":"Body Bagger","path":"http:\/\/cdn.akamai.steamstatic.com\/steamcommunity\/public\/images\/apps\/730\/b11ef0453168cd3d10684e184004f71dcc0faa82.jpg"},{"name":"Corpseman","path":"http:\/\/cdn.akamai.steamstatic.com\/steamcommunity\/public\/images\/apps\/730\/60d83a42df84fa5d84910af681370579e3bb16bf.jpg"},{"name":"God of War","path":"http:\/\/cdn.akamai.steamstatic.com\/steamcommunity\/public\/images\/apps\/730\/2c2bb56a4f7376b53eeaf8e6d84044460b0d1cf2.jpg"},{"name":"Second to None","path":"http:\/\/cdn.akamai.steamstatic.com\/steamcommunity\/public\/images\/apps\/730\/986a53e24114699cb1f230f52b55b27e0de28ecf.jpg"},{"name":"Counter-Counter-Terrorist","path":"http:\/\/cdn.akamai.steamstatic.com\/steamcommunity\/public\/images\/apps\/730\/c09cb3fe34841fd1000a48c3b7825c4fde026188.jpg"},{"name":"Rite of First Defusal","path":"http:\/\/cdn.akamai.steamstatic.com\/steamcommunity\/public\/images\/apps\/730\/b2027dac5a9883f0f145e78a33e531a58944f3ec.jpg"},{"name":"Short Fuse","path":"http:\/\/cdn.akamai.steamstatic.com\/steamcommunity\/public\/images\/apps\/730\/648550738f4845f12aa686a1b4ee8c4a51ec2348.jpg"}]},"release_date":{"coming_soon":false,"date":"22 Aug, 2012"},"support_info":{"url":"","email":""},"background":"http:\/\/cdn.akamai.steamstatic.com\/steam\/apps\/730\/page_bg_generated_v6b.jpg?t=1467065027"}}}