反序列化 JSON 时出现 C# 错误

Question

我正在使用 json.net 反序列化 WebApi 服务中传入的 json。

var lines = JsonConvert.DeserializeObject<RootObject>(json);

阅读了许多其他类似的答案后，它仍然抛出此错误：

The best overloaded method match for  'Newtonsoft.Json.JsonConvert.DeserializeObject<RootObject>(string)' has some invalid arguments

输入Postman中用于post的json：

{ "data": [
{"zipcode":"56033","line1":"610 4TH ST","city":"FROST","state":"MN","cid":"1770"},
{"zipcode":"56033","line1":"45375 30TH ST","city":"FROST","state":"MN","cid":"1771"},
{"zipcode":"56033","line1":"115 4TH ST","city":"FROST","state":"MN","cid":"1772"}
]}

poco 类是使用http://json2csharp.com创建的。

  public class Datum
  {
    public string zipcode { get; set; }
    public string line1 { get; set; }
    public string city { get; set; }
    public string state { get; set; }
    public string cid { get; set; }
  }

  public class RootObject
  {
    public List<Datum> data { get; set; }
  }

这是我调试 api 时看到的：

{{
  "data": [
    {
      "zipcode": "56032-0056",
      "line1": "208 MAIN BOX 56",
      "city": "FREEBORN",
      "state": "MN",
      "cid": "1732"
    },
    {
      "zipcode": "56033",
      "line1": "610 4TH ST",
      "city": "FROST",
      "state": "MN",
      "cid": "1770"
    },
    {
      "zipcode": "56033",
      "line1": "45375 30TH ST",
      "city": "FROST",
      "state": "MN",
      "cid": "1771"
    },
    {
      "zipcode": "56033",
      "line1": "115 4TH ST",
      "city": "FROST",
      "state": "MN",
      "cid": "1772"
    },
    {
      "zipcode": "56033",
      "line1": "E 4TH ST",
      "city": "FROST",
      "state": "MN",
      "cid": "1773"
    }
  ]
}}

不知道为什么 webapi 添加一组额外的花括号或如何防止它们。

有人看到我缺少什么吗？

Answer 1

如果你的 json 变量是一个字符串，它就会起作用。这是一个.NET Fiddle演示。