Newtonsoft.Json.Linq.JToken.SelectTokenを使用してJSONを解析します。

Question

JSONを解析して、次のスニペットでVIN番号の値を取得しようとしています。 SelectToken呼び出しがNULL値を返しています。 私はここで何が起こっているかを識別することができません

• http://jsonpath.com
• https://jsonpath.curiousconcept.com

そこに私は、次のWebサイト上でテストするために、同じトークンを使用してみました、それが動作します。このトークンはNewtownsoft.Jsonでサポートされていないので、それをある、またはそれが何か他のものである

[Test] 
    public void Test() 
    { 
     string responseContent = 
      "{\"GetAdvisorWipDetailPageResponse\":{\"AdvisorDetailPage\":{\"TaxLabel\":\"VAT\",\"Currency\":{\"Code\":\"UKL\",\"Description\":\"Sterling\",\"Symbol\":\"£\",\"Precision\":\"2\"},\"LastMileage\":\"0\",\"NetAmount\":\"52.73\",\"VATAmount\":\"10.55\",\"TotalAmount\":\"63.28\",\"VATRate\":\"20.00\",\"RTSLabourRate\":\"55.50\",\"DateOut\":\"2017-09-06\",\"TimeOut\":\"16:00\",\"CustomerName\":\"S 4133166Portor\",\"CustomerDetails\":{\"Name\":\"S 4133166Portor\",\"Address\":\"1 Alvin Street\\\\nHungerford\\\\n\\\\n\\\\n\"},\"ListSection\":[{\"Type\":\"2\",\"SectionDesc\":\"Vehicle Details\",\"Cols\":\"2\",\"DisplayRows\":\"10\",\"Rows\":\"10\",\"ListRow\":[{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Registration:\",\"Col2\":\"PRA4133166\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"VIN:\",\"Col2\":\"4133166\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Make:\",\"Col2\":\"Citroen\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Model:\",\"Col2\":\"C3 Picasso\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Colour:\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Fuel Type:\",\"Col2\":\"Petrol\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Last known odometer:\",\"Col2\":\"0\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Next service due:\",\"Col2\":\"1200 or 06/07/2018\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Registration date:\",\"Col2\":\"06/09/2017\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"MOT due date:\",\"Col2\":\"06/07/2018\"}}],\"Variant\":{\"Class\":\"CAR\",\"Desc\":\"Car\",\"Variants\":{\"Variant\":[{\"Class\":\"BIKE\",\"Desc\":\"Motorcycle\"},{\"Class\":\"CAR\",\"Desc\":\"Car\"},{\"Class\":\"COMP\",\"Desc\":\"Component vehicle\"},{\"Class\":\"HGV\",\"Desc\":\"Heavy Goods Vehicle\"},{\"Class\":\"LCV\",\"Desc\":\"Light Commercial Vehicle\"}]}}},{\"Type\":\"2\",\"SectionDesc\":\"Today's Service Details\",\"Cols\":\"2\",\"DisplayRows\":\"6\",\"Rows\":\"6\",\"ListRow\":[{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Repair number:\",\"Col2\":\"20285\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Account:\",\"Col2\":\"C0002 - Service Retail Cash Sales\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Notes:\",\"Col2\":\"Carry out repair :-\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Goods value:\",\"Col2\":\"£52.73\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"VAT value:\",\"Col2\":\"£10.55\"}},{\"WipNo\":\"20285\",\"Row\":{\"Col1\":\"Total value:\",\"Col2\":\"£63.28\"}}]},{\"Type\":\"4\",\"SectionDesc\":\"Recent Service History\"}],\"VHCCompleted\":\"0\",\"Reminders\":\"0\",\"PreviousVHC\":{\"Available\":\"0\"}},\"Version\":\"3.228\",\"Partition\":\"972\",\"Startup\":\"2017-09-06T15:40\",\"RequestsServiced\":\"1\"}}"; 
     string key = "GetAdvisorWipDetailPageResponse.AdvisorDetailPage.ListSection[0].ListRow[*].[?(@.Col1=='VIN:')].Col2"; 
     var content = JObject.Parse(responseContent); 
     var value = content.SelectToken(key).ToString(); 
    } 

アンエスケープされた文字列は、

{"GetAdvisorWipDetailPageResponse":{"AdvisorDetailPage":{"TaxLabel":"VAT","Currency":{"Code":"UKL","Description":"Sterling","Symbol":"£","Precision":"2"},"LastMileage":"0","NetAmount":"52.73","VATAmount":"10.55","TotalAmount":"63.28","VATRate":"20.00","RTSLabourRate":"55.50","DateOut":"2017-09-06","TimeOut":"16:00","CustomerName":"S 4133166Portor","CustomerDetails":{"Name":"S 4133166Portor","Address":"1 Alvin Street\\nHungerford\\n\\n\\n"},"ListSection":[{"Type":"2","SectionDesc":"Vehicle Details","Cols":"2","DisplayRows":"10","Rows":"10","ListRow":[{"WipNo":"20285","Row":{"Col1":"Registration:","Col2":"PRA4133166"}},{"WipNo":"20285","Row":{"Col1":"VIN:","Col2":"4133166"}},{"WipNo":"20285","Row":{"Col1":"Make:","Col2":"Citroen"}},{"WipNo":"20285","Row":{"Col1":"Model:","Col2":"C3 Picasso"}},{"WipNo":"20285","Row":{"Col1":"Colour:"}},{"WipNo":"20285","Row":{"Col1":"Fuel Type:","Col2":"Petrol"}},{"WipNo":"20285","Row":{"Col1":"Last known odometer:","Col2":"0"}},{"WipNo":"20285","Row":{"Col1":"Next service due:","Col2":"1200 or 06/07/2018"}},{"WipNo":"20285","Row":{"Col1":"Registration date:","Col2":"06/09/2017"}},{"WipNo":"20285","Row":{"Col1":"MOT due date:","Col2":"06/07/2018"}}],"Variant":{"Class":"CAR","Desc":"Car","Variants":{"Variant":[{"Class":"BIKE","Desc":"Motorcycle"},{"Class":"CAR","Desc":"Car"},{"Class":"COMP","Desc":"Component vehicle"},{"Class":"HGV","Desc":"Heavy Goods Vehicle"},{"Class":"LCV","Desc":"Light Commercial Vehicle"}]}}},{"Type":"2","SectionDesc":"Today's Service Details","Cols":"2","DisplayRows":"6","Rows":"6","ListRow":[{"WipNo":"20285","Row":{"Col1":"Repair number:","Col2":"20285"}},{"WipNo":"20285","Row":{"Col1":"Account:","Col2":"C0002 - Service Retail Cash Sales"}},{"WipNo":"20285","Row":{"Col1":"Notes:","Col2":"Carry out repair :-"}},{"WipNo":"20285","Row":{"Col1":"Goods value:","Col2":"£52.73"}},{"WipNo":"20285","Row":{"Col1":"VAT value:","Col2":"£10.55"}},{"WipNo":"20285","Row":{"Col1":"Total value:","Col2":"£63.28"}}]},{"Type":"4","SectionDesc":"Recent Service History"}],"VHCCompleted":"0","Reminders":"0","PreviousVHC":{"Available":"0"}},"Version":"3.228","Partition":"972","Startup":"2017-09-06T15:40","RequestsServiced":"1"}} 

Answer 1

次JSONPathクエリ文字列がJson.NETで動作するここにあります：

string key = "GetAdvisorWipDetailPageResponse.AdvisorDetailPage.ListSection[0].ListRow[?(@.Row.Col1=='VIN:')].Row.Col2"; 

そして結果として、4133166が返されます。

作業.Net fiddle。

これはなぜ機能しますか？

{ 
    "ListRow":[ 
     { 
     "WipNo":"20285", 
     "Row":{ 
      "Col1":"Registration:", 
      "Col2":"PRA4133166" 
     } 
     }, 
     { 
     "WipNo":"20285", 
     "Row":{ 
      "Col1":"VIN:", 
      "Col2":"4133166" 
     } 
     } 
    ] 
} 

あなたはRow.Col1が特定の値、特に"VIN:"を持っているListRow配列のエントリを探しています：私はあなたのJSONのListRowセクションを簡素化した場合、それはこのようになります。値が見つかると、Row.Col2の値を選択します。 JSONPathクエリ文字列

ListRow[?(@.Row.Col1=='VIN:')].Row.Col2 

これはありますか？

（あなたのクエリでは、（特に、）ListRow配列項目オブジェクトの内部オブジェクト内のColの値をフィルタリングするオブジェクト内に直接ネストされたオブジェクトにフィルタを適用しようとしている。これは明らかに、JSONで実装されていません。 NET 10.0.3以降、詳細はJson.NET JSONPath query not returning expected resultsを参照してください）