c# - 当我将 json 字符串反序列化为 C# 对象时，类为空

Question

这是使用 Console.Writeline 打印的 Json 字符串:

{"access_token":"eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJodHRwczpcL1wvYXBpLmRydW1zdGlrLmFwcFwvYXBpXC9sb2dpbiIsImlhdCI6MTYwMzgxNTcxMywiZXhwIjoxNjAzODE5MzEzLCJuYmYiOjE2MDM4MTU3MTMsImp0aSI6InJhU1dJSHBJaWR0YnhjTUUiLCJzdWIiOjQ1LCJwcnYiOiI4N2UwYWYxZWY5ZmQxNTgxMmZkZWM5NzE1M2ExNGUwYjA0NzU0NmFhIn0.aaQoQVKTSMFWCEOMv9psVsMeOJqpC5giLfwZ0Uic444","token_type":"bearer","expires_in":3600}

我想构建一个 C# 对象:

public class eltoken
    {
        [JsonProperty("access_token")]
        public string AccesToken { get; set; }
        [JsonProperty("token_type")]
        public string TokenType { get; set; }
        [JsonProperty("expires_in")]

        public long ExpiresIn { get; set; }
    }

 eltoken test = JsonConvert.DeserializeObject<eltoken>(response.Content.ReadAsStringAsync().Result.ToString());

                    //------------
                    Console.WriteLine(test.AccesToken);

但我不明白为什么它是空的。

Answer 1

您可能没有正确等待。首先，这不是使用异步 API 的正确方法:

eltoken test = JsonConvert.DeserializeObject<eltoken>(response.Content.ReadAsStringAsync().Result.ToString());

尝试一下:

var json = await response.Content.ReadAsStringAsync();
// debug write/inspect json here
eltoken test = JsonConvert.DeserializeObject<eltoken>(json);

---

从根本上来说，反序列化步骤没问题，所以问题可能是 JSON 不是您想象的那样:

using Newtonsoft.Json;
using System;

class P
{
    static void Main()
    {
        var json = @"{""access_token"":""eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJodHRwczpcL1wvYXBpLmRydW1zdGlrLmFwcFwvYXBpXC9sb2dpbiIsImlhdCI6MTYwMzgxNTcxMywiZXhwIjoxNjAzODE5MzEzLCJuYmYiOjE2MDM4MTU3MTMsImp0aSI6InJhU1dJSHBJaWR0YnhjTUUiLCJzdWIiOjQ1LCJwcnYiOiI4N2UwYWYxZWY5ZmQxNTgxMmZkZWM5NzE1M2ExNGUwYjA0NzU0NmFhIn0.aaQoQVKTSMFWCEOMv9psVsMeOJqpC5giLfwZ0Uic444"",""token_type"":""bearer"",""expires_in"":3600}";
        eltoken test = JsonConvert.DeserializeObject<eltoken>(json);
        Console.WriteLine(test.ExpiresIn);
        Console.WriteLine(test.TokenType);
        Console.WriteLine(test.AccesToken);
    }
}
public class eltoken
{
    [JsonProperty("access_token")]
    public string AccesToken { get; set; }
    [JsonProperty("token_type")]
    public string TokenType { get; set; }
    [JsonProperty("expires_in")]
    public long ExpiresIn { get; set; }
}

其输出如预期:

3600
bearer
eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJodHRwczpcL1wvYXBpLmRydW1zdGlrLmFwcFwvYXBpXC9sb2dpbiIsImlhdCI6MTYwMzgxNTcxMywiZXhwIjoxNjAzODE5MzEzLCJuYmYiOjE2MDM4MTU3MTMsImp0aSI6InJhU1dJSHBJaWR0YnhjTUUiLCJzdWIiOjQ1LCJwcnYiOiI4N2UwYWYxZWY5ZmQxNTgxMmZkZWM5NzE1M2ExNGUwYjA0NzU0NmFhIn0.aaQoQVKTSMFWCEOMv9psVsMeOJqpC5giLfwZ0Uic444