c# - 从API获取数字并将其放入变量中

我想在此api中获取价格值usd并将其放在变量中：https://api.coingecko.com/api/v3/simple/price?ids=veco&vs_currencies=usd我已经尝试过此代码，但出现错误：public static void StartGet() { HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create(string.Format(VECO.VecoPriceURL)); WebReq.Method = "GET"; HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse(); string jsonString; using (Stream stream = WebResp.GetResponseStream()) { StreamReader reader = new StreamReader(stream, System.Text.Encoding.UTF8); jsonString = reader.ReadToEnd(); } List<VECO.Coin> items = JsonConvert.DeserializeObject<List<VECO.Coin>>(jsonString); foreach (var item in items) { Console.WriteLine(item.usd); } }public class VECO{ public static string VecoPriceURL = "https://api.coingecko.com/api/v3/simple/price?ids=veco&vs_currencies=usd"; public class Coin { public string usd { get; set; } }}错误：Newtonsoft.Json.JsonSerializationException: 'Cannot deserialize the currentJSON object (e.g. {"name":"value"}) into type'System.Collections.Generic.List`1[ConsoleProgram.VECO+Coin]' because thetype requires a JSON array (e.g. [1,2,3]) to deserialize correctly.To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) orchange the deserialized type so that it is a normal .NET type (e.g. not aprimitive type like integer, not a collection type like an array or List<T>)that can be deserialized from a JSON object. JsonObjectAttribute can also beadded to the type to force it to deserialize from a JSON object.Path 'veco', line 1, position 8.' 最佳答案 您的数据结构需要稍有不同。public class Veco{ public decimal usd { get; set; }}public class RootObject{ public Veco veco { get; set; }}请注意，Json不是数组或List，因此您还需要在JsonConvert.DeserializeObject方法中使用List 。相反，您需要执行以下操作。var result = JsonConvert.DeserializeObject<RootObject>(jsonString);例，var jsonString = @"{'veco':{'usd':0.01558532}}";var result = JsonConvert.DeserializeObject<RootObject>(jsonString);Console.WriteLine($"USD Rate : {result.veco.usd}");输出量USD Rate 0.01558532重写您的方法， public static void StartGet() { HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create(string.Format(VECO.VecoPriceURL)); WebReq.Method = "GET"; HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse(); string jsonString; using (Stream stream = WebResp.GetResponseStream()) { StreamReader reader = new StreamReader(stream, System.Text.Encoding.UTF8); jsonString = reader.ReadToEnd(); } var item = JsonConvert.DeserializeObject<RootObject>(jsonString); Console.WriteLine(item.veco.usd); }更新资料根据您的评论，我将按照以下方式重写您的方法。您不再需要数据结构。public static void StartGet(string id){ var url = $"https://api.coingecko.com/api/v3/simple/price?ids={id}&vs_currencies=usd"; HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create(url); WebReq.Method = "GET"; HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse(); string jsonString; using (Stream stream = WebResp.GetResponseStream()) { StreamReader reader = new StreamReader(stream, System.Text.Encoding.UTF8); jsonString = reader.ReadToEnd(); } var result = JsonConvert.DeserializeObject<JToken>(jsonString); Console.WriteLine($"For {id},USD Rate : {result[id].Value<string>("usd")}");}现在您可以使用以下方法StartGet("veco");StartGet("eos");StartGet("uraniumx");输出量For veco,USD Rate : 0.01581513For eos,USD Rate : 2.42For uraniumx,USD Rate : 0.890397