我想在此api中获取价格为usd
并将其放入变量中:
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 current
JSON object (e.g. {"name":"value"}) into type
'System.Collections.Generic.List`1[ConsoleProgram.VECO+Coin]' because the
type 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]) or
change the deserialized type so that it is a normal .NET type (e.g. not a
primitive type like integer, not a collection type like an array or List<T>)
that can be deserialized from a JSON object. JsonObjectAttribute can also be
added to the type to force it to deserialize from a JSON object.
Path 'veco', line 1, position 8.'
答案 0 :(得分:2)
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);
示例
var jsonString = @"{'veco':{'usd':0.01558532}}";
var result = JsonConvert.DeserializeObject<RootObject>(jsonString);
Console.WriteLine($"USD Rate : {result.veco.usd}");
输出
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
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
For veco,USD Rate : 0.01581513
For eos,USD Rate : 2.42
For uraniumx,USD Rate : 0.890397