c# - 如何在 C# 中解析/反序列化从 rest 服务返回的 JSON

Question

我从结构如下的 URL 获取字符串格式的 JSON，但我无法解析它。它抛出异常，知道如何解析它吗？

结构如下:

{
   "pathway":{
      "patients":{
         "patient":[
            {
               "patientid":"7703176",
               "name":"Abbot, Bud",
               "status":"Invited",
               "start":"2013-12-07",
               "last":"N/A",
               "engagement":"N/A",
               "drug":"N/A",
               "adherence":"N/A",
               "vitals":"Current",
               "last_appointment":"2013-10-25",
               "next_appointment":"None"
            },
            {
               "patientid":"5089554",
               "name":"Brennan, Bonnie",
               "status":"Connected",
               "start":"2013-12-29",
               "last":"2014-02-01",
               "engagement":"Low",
               "drug":" ",
               "adherence":" ",
               "vitals":"Out of Date",
               "last_appointment":"2013-04-21",
               "next_appointment":"None"
            }
         ]
      }
   }
}

我是这样做的:

public class PathWayWrapper
{
    public pathway pathway { get; set; }
}

和

public class pathway
{
    public List<patient> patients { get; set; }
}

和

public class patient
{
    public long patientid { get; set; }
    public string name { get; set; }
    public string status { get; set; }
    public string start { get; set; }
    public string last { get; set; }
    public string engagement { get; set; }
    public string drug { get; set; }
    public string adherence { get; set; }
    public string vitals { get; set; }
    public string last_appointment { get; set; }
    public string next_appointment { get; set; }
}

这是我的解析代码:

StreamReader reader = new StreamReader(response.GetResponseStream());

string json = reader.ReadToEnd();

var Jsonobject = JsonConvert.DeserializeObject<PathWayWrapper>(json);

objPathway = Jsonobject.pathway;

Answer 1

您要反序列化的类不正确。您缺少“患者”类(class)。

当我有 JSON 并试图反序列化它时，我喜欢使用 http://json2csharp.com在反序列化类中生成第一次切割。它比尝试手动操作更准确。

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

public class Patient
{
    public string patientid { get; set; }
    public string name { get; set; }
    public string status { get; set; }
    public string start { get; set; }
    public string last { get; set; }
    public string engagement { get; set; }
    public string drug { get; set; }
    public string adherence { get; set; }
    public string vitals { get; set; }
    public string last_appointment { get; set; }
    public string next_appointment { get; set; }
}

public class Patients
{
    public List<Patient> patient { get; set; }
}

public class Pathway
{
    public Patients patients { get; set; }
}

public class RootObject
{
    public Pathway pathway { get; set; }
}

附言您得到的异常通常是一个很好的线索，表明您定义反序列化类的方式有问题。

Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[ConsoleApplication1.Program+patient]' 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) 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.