LINQ to JSON - 查询对象或数组

Question

我正在尝试获取SEDOL和ADP值的列表.以下是我的json文字:

{
    "DataFeed" : {
        "@FeedName" : "AdminData",
        "Issuer" : [{
                "id" : "1528",
                "name" : "ZYZ.A a Test Company",
                "clientCode" : "ZYZ.A",
                "securities" : {
                    "Security" : {
                        "id" : "1537",
                        "sedol" : "SEDOL111",
                        "coverage" : {
                            "Coverage" : [{
                                    "analyst" : {
                                        "@id" : "164",
                                        "@clientCode" : "SJ",
                                        "@firstName" : "Steve",
                                        "@lastName" : "Jobs",
                                        "@rank" : "1"
                                    }
                                }, {
                                    "analyst" : {
                                        "@id" : "261",
                                        "@clientCode" : "BG",
                                        "@firstName" : "Bill",
                                        "@lastName" : "Gates",
                                        "@rank" : "2"
                                    }
                                }
                            ]
                        },
                        "customFields" : {
                            "customField" : [{
                                    "@name" : "ADP Security Code",
                                    "@type" : "Textbox",
                                    "values" : {
                                        "value" : "ADPSC1111"
                                    }
                                }, {
                                    "@name" : "Top 10 - Select one or many",
                                    "@type" : "Dropdown, multiple choice",
                                    "values" : {
                                        "value" : ["Large Cap", "Cdn Small Cap", "Income"]
                                    }
                                }
                            ]
                        }
                    }
                }
            }, {
                "id" : "1519",
                "name" : "ZVV Test",
                "clientCode" : "ZVV=US",
                "securities" : {
                    "Security" : [{
                            "id" : "1522",
                            "sedol" : "SEDOL112",
                            "coverage" : {
                                "Coverage" : {
                                    "analyst" : {
                                        "@id" : "79",
                                        "@clientCode" : "MJ",
                                        "@firstName" : "Michael",
                                        "@lastName" : "Jordan",
                                        "@rank" : "1"
                                    }
                                }
                            },
                            "customFields" : {
                                "customField" : [{
                                        "@name" : "ADP Security Code",
                                        "@type" : "Textbox",
                                        "values" : {
                                            "value" : "ADPS1133"
                                        }
                                    }, {
                                        "@name" : "Top 10 - Select one or many",
                                        "@type" : "Dropdown, multiple choice",
                                        "values" : {
                                            "value" : ["Large Cap", "Cdn Small Cap", "Income"]
                                        }
                                    }
                                ]
                            }
                        }, {
                            "id" : "1542",
                            "sedol" : "SEDOL112",
                            "customFields" : {
                                "customField" : [{
                                        "@name" : "ADP Security Code",
                                        "@type" : "Textbox",
                                        "values" : {
                                            "value" : "ADPS1133"
                                        }
                                    }, {
                                        "@name" : "Top 10 - Select one or many",
                                        "@type" : "Dropdown, multiple choice",
                                        "values" : {
                                            "value" : ["Large Cap", "Cdn Small Cap", "Income"]
                                        }
                                    }
                                ]
                            }
                        }
                    ]
                }
            }
        ]
    }
}

这是我到目前为止的代码:

var compInfo = feed["DataFeed"]["Issuer"]
.Select(p => new {  
    Id = p["id"],
    CompName = p["name"],
    SEDOL = p["securities"]["Security"].OfType<JArray>() ? 
        p["securities"]["Security"][0]["sedol"] : 
        p["securities"]["Security"]["sedol"]
    ADP = p["securities"]["Security"].OfType<JArray>() ? 
        p["securities"]["Security"][0]["customFields"]["customField"][0]["values"]["value"] : 
        p["securities"]["Security"]["customFields"]["customField"][0]["values"]["value"]
});

我得到的错误是:

使用无效键值访问JArray值:"sedol".预期Int32数组索引

我想我真的很接近搞清楚了.我该怎么做来修复代码？如果有另一种获得SEDOL和ADP value,请不要让我知道？

[UPDATE1]我开始使用动态ExpandoObject.这是我到目前为止使用的代码:

dynamic obj = JsonConvert.DeserializeObject<ExpandoObject>(json, new ExpandoObjectConverter());
foreach (dynamic element in obj)
{
    Console.WriteLine(element.DataFeed.Issuer[0].id);
    Console.WriteLine(element.DataFeed.Issuer[0].securities.Security.sedol);
    Console.ReadLine();
}

但我现在收到错误'ExpandoObject' does not contain a definition for 'DataFeed' and no extension method 'DataFeed' accepting a first argument of type 'ExpandoObject' could be found. 注意:我知道这个json文本格式不正确.一个实例有一个数组,另一个实例是一个对象.我希望代码足够敏捷以处理这两个实例.

[UPDATE2]感谢@dbc帮助我使用我的代码到目前为止.我已经更新了上面的json文本,以便与我当前的环境紧密匹配.我现在能够获得SEDOL和ADP代码.但是,当我试图获得第一个分析师时,我的代码只适用于对象,并为作为数组一部分的分析人员生成空值.这是我目前的代码:

var compInfo = from issuer in feed.SelectTokens("DataFeed.Issuer").SelectMany(i => i.ObjectsOrSelf())
           let security = issuer.SelectTokens("securities.Security").SelectMany(s => s.ObjectsOrSelf()).FirstOrDefault()
           where security != null
           select new
           {
               Id = (string)issuer["id"], // Change to (string)issuer["id"] if id is not necessarily numeric.
               CompName = (string)issuer["name"],
               SEDOL = (string)security["sedol"],
               ADP = security["customFields"]
                .DescendantsAndSelf()
                .OfType<JObject>()
                .Where(o => (string)o["@name"] == "ADP Security Code")
                .Select(o => (string)o.SelectToken("values.value"))
                .FirstOrDefault(),
              Analyst = security["coverage"]
                .DescendantsAndSelf()
                .OfType<JObject>()
                .Select(jo => (string)jo.SelectToken("Coverage.analyst.@lastName"))
                .FirstOrDefault(),
           };

我需要更改为始终选择第一位分析师？

Answer 1

如果您希望所有SEDOL和ADP值都包含相关的颁发者ID和CompName,则可以执行以下操作:

var compInfo = from issuer in feed.SelectTokens("DataFeed.Issuer").SelectMany(i => i.ObjectsOrSelf())
               from security in issuer.SelectTokens("securities.Security").SelectMany(s => s.ObjectsOrSelf())
               select new
               {
                   Id = (long)issuer["id"], // Change to (string)issuer["id"] if id is not necessarily numeric.
                   CompName = (string)issuer["name"],
                   SEDOL = (string)security["sedol"],
                   ADP = security["customFields"]
                    .DescendantsAndSelf()
                    .OfType<JObject>()
                    .Where(o => (string)o["@name"] == "ADP Security Code")
                    .Select(o => (string)o.SelectToken("values.value"))
                    .FirstOrDefault(),
               };

使用扩展方法:

public static class JsonExtensions
{
    public static IEnumerable<JToken> DescendantsAndSelf(this JToken node)
    {
        if (node == null)
            return Enumerable.Empty<JToken>();
        var container = node as JContainer;
        if (container != null)
            return container.DescendantsAndSelf();
        else
            return new[] { node };
    }

    public static IEnumerable<JObject> ObjectsOrSelf(this JToken root)
    {
        if (root is JObject)
            yield return (JObject)root;
        else if (root is JContainer)
            foreach (var item in ((JContainer)root).Children())
                foreach (var child in item.ObjectsOrSelf())
                    yield return child;
        else
            yield break;
    }
}

然后

Console.WriteLine(JsonConvert.SerializeObject(compInfo, Formatting.Indented));

生产:

[
  {
    "Id": 1528,
    "CompName": "ZYZ.A a Test Company",
    "SEDOL": "SEDOL111",
    "ADP": "ADPSC1111"
  },
  {
    "Id": 1519,
    "CompName": "ZVV Test",
    "SEDOL": "SEDOL112",
    "ADP": "ADPS1133"
  },
  {
    "Id": 1519,
    "CompName": "ZVV Test",
    "SEDOL": "SEDOL112",
    "ADP": "ADPS1133"
  }
]

但是,在您迄今为止编写的查询中,您似乎只是尝试为每个颁发者返回第一个 SEDOL和ADP.如果这真的是你想要的,那么:

var compInfo = from issuer in feed.SelectTokens("DataFeed.Issuer").SelectMany(i => i.ObjectsOrSelf())
               let security = issuer.SelectTokens("securities.Security").SelectMany(s => s.ObjectsOrSelf()).FirstOrDefault()
               where security != null
               select new
               {
                   Id = (long)issuer["id"], // Change to (string)issuer["id"] if id is not necessarily numeric.
                   CompName = (string)issuer["name"],
                   SEDOL = (string)security["sedol"],
                   ADP = security["customFields"]
                    .DescendantsAndSelf()
                    .OfType<JObject>()
                    .Where(o => (string)o["@name"] == "ADP Security Code")
                    .Select(o => (string)o.SelectToken("values.value"))
                    .FirstOrDefault(),
               };

结果如下:

[
  {
    "Id": 1528,
    "CompName": "ZYZ.A a Test Company",
    "SEDOL": "SEDOL111",
    "ADP": "ADPSC1111"
  },
  {
    "Id": 1519,
    "CompName": "ZVV Test",
    "SEDOL": "SEDOL112",
    "ADP": "ADPS1133"
  }
]

顺便说一句,由于您的JSON是多态的(属性有时是对象的数组,有时只是对象),我不认为反序列化为类层次结构或ExpandoObject更容易.

更新

鉴于更新后的JSON,您可以使用SelectTokens()与JSONPath递归搜索操作符..查找第一个分析师的姓氏,其中递归搜索运营商处理该分析师可能会或可能不会被包含在数组中的事实:

var compInfo = from issuer in feed.SelectTokens("DataFeed.Issuer").SelectMany(i => i.ObjectsOrSelf())
               let security = issuer.SelectTokens("securities.Security").SelectMany(s => s.ObjectsOrSelf()).FirstOrDefault()
               where security != null
               select new
               {
                   Id = (string)issuer["id"], // Change to (string)issuer["id"] if id is not necessarily numeric.
                   CompName = (string)issuer["name"],
                   SEDOL = (string)security["sedol"],
                   ADP = (string)security["customFields"]
                    .DescendantsAndSelf()
                    .OfType<JObject>()
                    .Where(o => (string)o["@name"] == "ADP Security Code")
                    .Select(o => o.SelectToken("values.value"))
                    .FirstOrDefault(),
                   Analyst = (string)security.SelectTokens("coverage.Coverage..analyst.@lastName").FirstOrDefault(),
               };