C# 使用自定义格式序列化JSON字符串

我有一个通用列表对象，它将下表作为自己的值保存

CountryID | StateID | StateName
--------------------------------
    1     |  1      |  Alabama    
    1     |  2      |  California
    1     |  3      |  Florida
    1     |  4      |  Hawaii   
    2     |  5      |  London
    2     |  6      |  Oxford

我想根据列表对象创建JSON字符串。 我希望得到的JSON格式如下所示

{           
    1: { '1': 'Alabama', '2': 'California', '3': 'Florida', '4': 'Hawaii' },
    2: { '5': 'London', '6': 'Oxford' }
};

{
[

{"CountryID":1,"StateID":1,"StateName":"Alabama"},
{"CountryID":1,"StateID":2,"StateName":"California"},
{"CountryID":1,"StateID":3,"StateName":"Florida"},
{"CountryID":1,"StateID":4,"StateName":"Hawaii"},
{"CountryID":2,"StateID":5,"StateName":"London"},
{"CountryID":2,"StateID":6,"StateName":"Oxford"}

]
}

我使用下面的类来生成JSON对象

public static class JSONHelper
{
    public static string ToJSON(this object obj)
    {
        JavaScriptSerializer serializer = new JavaScriptSerializer();
        return serializer.Serialize(obj);
    }

    public static string ToJSON(this object obj, int recursionDepth)
    {
        JavaScriptSerializer serializer = new JavaScriptSerializer();
        serializer.RecursionLimit = recursionDepth;            
        return serializer.Serialize(obj);
    }
}

但是，当我完成调用ToJSON方法时得到的实际输出如下所示

{           
    1: { '1': 'Alabama', '2': 'California', '3': 'Florida', '4': 'Hawaii' },
    2: { '5': 'London', '6': 'Oxford' }
};

{
[

{"CountryID":1,"StateID":1,"StateName":"Alabama"},
{"CountryID":1,"StateID":2,"StateName":"California"},
{"CountryID":1,"StateID":3,"StateName":"Florida"},
{"CountryID":1,"StateID":4,"StateName":"Hawaii"},
{"CountryID":2,"StateID":5,"StateName":"London"},
{"CountryID":2,"StateID":6,"StateName":"Oxford"}

]
}

那么，有谁能给我一个建议，我该如何制作我想要的JSON字符串格式？

---

每一个建议都将不胜感激。

将其转换为指定格式的最简单方法是将自定义类转换为嵌套字典：

Dictionary<Int32,Dictionary<String, String>>

然后序列化该输出

Dictionary<Int32,Dictionary<String, String>> countryDict= new Dictionary<Int32,Dictionary<String, String>>()
foreach(var item in myGenericList){
    Dictionary<Int32,Dictionary<String, String> stateDict = 
    countryDict[item.CountryID] ?? new Dictionary<Int32,Dictionary<String, String>>();
    stateDict.Add(item.StateID.ToString(),item.StateName) 
}

---

将其转换为指定格式的最简单方法是将自定义类转换为嵌套字典：

Dictionary<Int32,Dictionary<String, String>>

然后序列化该输出

Dictionary<Int32,Dictionary<String, String>> countryDict= new Dictionary<Int32,Dictionary<String, String>>()
foreach(var item in myGenericList){
    Dictionary<Int32,Dictionary<String, String> stateDict = 
    countryDict[item.CountryID] ?? new Dictionary<Int32,Dictionary<String, String>>();
    stateDict.Add(item.StateID.ToString(),item.StateName) 
}

---

这样做的一个简单方法似乎是使用LINQ选择字典，然后将字典对象发送到JavascriptSerializer

我们有：

var list = new[]
               {
                   new {CountryID = 1, StateID = 1, StateName = "Alabama"},
                   new {CountryID = 1, StateID = 2, StateName = "California"},
                   new {CountryID = 1, StateID = 3, StateName = "Florida"},
                   new {CountryID = 1, StateID = 4, StateName = "Hawaii"},
                   new {CountryID = 2, StateID = 5, StateName = "London"},
                   new {CountryID = 2, StateID = 6, StateName = "Oxford"}
               };

然后我们可以对其递归调用.ToDictionary以获得以下内容：

var d = list
    .GroupBy(x=>x.CountryID)
    .ToDictionary(g=> g.Key.ToString(), 
        g => g.ToDictionary(x => x.StateID.ToString(),x => x.StateName));

var serializer = new JavaScriptSerializer();
return serializer.Serialize(d);

它返回您请求的JSON

---

注意：您必须在字典键上调用.ToString，因为JavaScriptSerializer似乎在键不是字符串的字典上失败…

一种简单的方法是使用LINQ选择字典，然后将字典对象发送到JavaScriptSerializer

我们有：

var list = new[]
               {
                   new {CountryID = 1, StateID = 1, StateName = "Alabama"},
                   new {CountryID = 1, StateID = 2, StateName = "California"},
                   new {CountryID = 1, StateID = 3, StateName = "Florida"},
                   new {CountryID = 1, StateID = 4, StateName = "Hawaii"},
                   new {CountryID = 2, StateID = 5, StateName = "London"},
                   new {CountryID = 2, StateID = 6, StateName = "Oxford"}
               };

然后我们可以对其递归调用.ToDictionary以获得以下内容：

var d = list
    .GroupBy(x=>x.CountryID)
    .ToDictionary(g=> g.Key.ToString(), 
        g => g.ToDictionary(x => x.StateID.ToString(),x => x.StateName));

var serializer = new JavaScriptSerializer();
return serializer.Serialize(d);

它返回您请求的JSON

---

注意：您必须在字典键上调用.ToString，因为JavaScriptSerializer在具有非字符串键的字典上似乎失败…

您需要序列化字典，而不是列表，才能获得JSON。 给定这些类型定义：

public class Country
{
    public Country()
    {
        States = new List<State>();
    }
    public int         CountryID  { get; set; }
    public List<State> States     { get; set; }
}

public class State
{
    public int    StateID    { get; set; }
    public string StateName  { get; set; }
}

这使用了作为LINQ一部分的ToDictionary扩展方法

输出：

{"1":{"1":"Lzwuoge","2":"0lzpas"},"2":{"1":"Mqn3ul5k","2":"Kefzu"}}

---

要获得JSON，需要序列化字典，而不是列表。 给定这些类型定义：

public class Country
{
    public Country()
    {
        States = new List<State>();
    }
    public int         CountryID  { get; set; }
    public List<State> States     { get; set; }
}

public class State
{
    public int    StateID    { get; set; }
    public string StateName  { get; set; }
}

这使用了作为LINQ一部分的ToDictionary扩展方法

输出：

{"1":{"1":"Lzwuoge","2":"0lzpas"},"2":{"1":"Mqn3ul5k","2":"Kefzu"}}

---

调用时，您将什么对象传递到扩展方法中？@prashantht，我只是像var\u CountryNState=objRepository.CountryNState\u Select\u Lookup.CountryNState；///它是泛型列表对象_CountryNState.ToJSON；调用时，您将什么对象传递到扩展方法中？@prashantht，我只是像var\u CountryNState=objRepository.CountryNState\u Select\u Lookup.CountryNState；///它是泛型列表对象_CountryNState.ToJSON；你的回答帮助我很多，非常感谢@Leland Richardson你的回答帮助我很多，非常感谢@Leland Richardson