如何從指定級別獲取json節點？

Question

我有這樣的JSON：

{ 
    "treeview":[ 
     { 
     "text":"blah", 
     "nodes":[ 

     ] 
     }, 
     { 
     "text":"blah", 
     "nodes":[ 

     ] 
     }, 
     { 
     "text":"blah", 
     "nodes":[ 
      { 
       "text":"blah", 
       "nodes":[ 
        { 
        "text":"foo", 
        "nodes":[ 
         // I need to put data in here !!! 
        ] 
        } 
       ] 
      } 
     ] 
     }, 
     { 
     "text":"blah", 
     "nodes":[ 

     ] 
     }, 
     { 
     "text":"foo", 
     "nodes":[ 
      // Not here ! 
     ] 
     } 
    ] 
} 

我需要把價值「節點」元素，其中我是2級和「文本」等於「foo」上。

這裏是我試過到目前爲止：

var json = myJson; 
// First approach 
var selector = (JArray)json.SelectTokens($"$..treeview[?(@.text == 'foo')]"); 
// Second approach 
var selector2 = (JArray)json.SelectToken($"$.treeview[?(@...text == 'foo')]"); 

selector.Add(new JObject(new JProperty("text", "myValue")); 

我不明白怎麼「點」在查詢工作......我只知道，當你輸入2「點」它瀏覽整個JSON ...有沒有辦法只查詢一個特定的縮進級別？使用Newtonsoft.Json包

Answer 1

我想通了，是的，我們可以指定一個水平壓痕，當我們想查詢文本平原JSON，方法如下：

var json = myJson; 
var selector = (JArray)json.SelectTokens($"$.treeview[*].nodes[*].nodes[(@.text =='foo')].nodes"); 
selector.Add(new JObject(new JProperty("text", "myValue"))); 

你可以在這裏進行測試：http://jsonpath.com/

複製過去的json樣品中的JSON節和jsonPath補充一點：$.treeview[*].nodes[*].nodes[*].text

這是你如何能得到所需的"level of identation"的'foo'值，而不在陣列中指定的任何指標，只要使用這個'*'，而不是一個int

Answer 2

這是很容易的不僅僅是簡單的JSON文本對象工作...

...

class Program 
{ 
    static void Main(string[] args) 
    { 
     var jsonstring = "{\"text\":\"blah\",\"nodes\":[{\"text\":\"foo\", \"nodes\": []}, {\"text\":\"bar\", \"nodes\": []}, {\"text\":\"foo\", \"nodes\": []}]}"; 

     //This is the root node 
     var firstLevelNodes = JsonConvert.DeserializeObject<Node>(jsonstring); 

     //All the nodes in the root nodes node collection 
     var secondLevelNodes = firstLevelNodes.nodes; 

     //All of the nodes in the collections of the second level nodes 
     var thirdLevelNodes = secondLevelNodes.SelectMany(sln => sln.nodes); 


     Console.WriteLine("First Level Nodes: \n" + JsonConvert.SerializeObject(firstLevelNodes).PrettyPrint()); 
     Console.WriteLine(); 
     Console.WriteLine("Second Level Nodes: \n" + JsonConvert.SerializeObject(secondLevelNodes).PrettyPrint()); 
     Console.WriteLine(); 
     Console.WriteLine("Third Level Nodes: \n" + JsonConvert.SerializeObject(thirdLevelNodes).PrettyPrint()); 

     secondLevelNodes.First().nodes = new List<Node> { new Node { text = "new node" , nodes = new List<Node>() } }; 

     Console.WriteLine(); 
     Console.WriteLine("Third Level Nodes (with new node): \n" + JsonConvert.SerializeObject(thirdLevelNodes).PrettyPrint()); 

     Console.ReadLine(); 
    } 
} 

public static class JSONExtensions 
{ 
    public static string PrettyPrint(this string json) 
    { 
     dynamic parsedJson = JsonConvert.DeserializeObject(json); 
     return JsonConvert.SerializeObject(parsedJson, Formatting.Indented); 
    } 

} 


[Serializable] 
public class Node 
{ 
    public string text { get; set; } 
    public IEnumerable<Node> nodes { get; set; } 
} 

OUTPUT：

First Level Nodes: 
{ 
    "text": "blah", 
    "nodes": [ 
    { 
     "text": "foo", 
     "nodes": [] 
    }, 
    { 
     "text": "bar", 
     "nodes": [] 
    }, 
    { 
     "text": "foo", 
     "nodes": [] 
    } 
    ] 
} 

Second Level Nodes: 
[ 
    { 
    "text": "foo", 
    "nodes": [] 
    }, 
    { 
    "text": "bar", 
    "nodes": [] 
    }, 
    { 
    "text": "foo", 
    "nodes": [] 
    } 
] 

Third Level Nodes: 
[] 

Third Level Nodes (with new node): 
[ 
    { 
    "text": "new node", 
    "nodes": [] 
    } 
] 

編輯：

所以，如果你只想要的第二級節點有文本foo只使用..

var secondLevelFooNodes = secondLevelNodes.Where(sln=>sln.text == "foo"); 
//then use these nodes 

EDIT2：

使用您的實際JSON對象需要一個TreeView類，以及...

class Program 
{ 
    static void Main(string[] args) 
    { 
     var jsonstring = "{\"treeview\":[{\"text\":\"blah\",\"nodes\":[]},{\"text\":\"blah\",\"nodes\":[]},{\"text\":\"blah\",\"nodes\":[{\"text\":\"blah\",\"nodes\":[{\"text\":\"foo\",\"nodes\":[]}]}]},{\"text\":\"blah\",\"nodes\":[]},{\"text\":\"foo\",\"nodes\":[]}]}"; 

     //This is the root node 
     var treeView = JsonConvert.DeserializeObject<TreeView>(jsonstring); 

     //All the nodes in the root nodes node collection 
     var firstLevelNodes = treeView.treeview; 

     //All of the nodes in the collections of the first level nodes 
     var secondLevelNodes = firstLevelNodes.SelectMany(fln => fln.nodes); 

     //All of the nodes in the collections of the second level nodes 
     var thirdLevelNodes = secondLevelNodes.SelectMany(sln => sln.nodes); 

     Console.WriteLine("The TreeView: \n" + JsonConvert.SerializeObject(treeView, Formatting.Indented)); 

     thirdLevelNodes.First(sln => sln.text == "foo").nodes = new List<Node> { new Node { text = "new node", nodes = new List<Node>() } }; 

     Console.WriteLine(); 
     Console.WriteLine("The TreeView (with new node): \n" + JsonConvert.SerializeObject(treeView, Formatting.Indented)); 

     Console.ReadLine(); 
    } 
} 

[Serializable] 
public class Node 
{ 
    public string text { get; set; } 
    public IEnumerable<Node> nodes { get; set; } 
} 

[Serializable] 
public class TreeView 
{ 
    public IEnumerable<Node> treeview { get; set; } 
} 

OUTPUT：

The TreeView: 
{ 
    "treeview": [ 
    { 
     "text": "blah", 
     "nodes": [] 
    }, 
    { 
     "text": "blah", 
     "nodes": [] 
    }, 
    { 
     "text": "blah", 
     "nodes": [ 
     { 
      "text": "blah", 
      "nodes": [ 
      { 
       "text": "foo", 
       "nodes": [] 
      } 
      ] 
     } 
     ] 
    }, 
    { 
     "text": "blah", 
     "nodes": [] 
    }, 
    { 
     "text": "foo", 
     "nodes": [] 
    } 
    ] 
} 

The TreeView (with new node): 
{ 
    "treeview": [ 
    { 
     "text": "blah", 
     "nodes": [] 
    }, 
    { 
     "text": "blah", 
     "nodes": [] 
    }, 
    { 
     "text": "blah", 
     "nodes": [ 
     { 
      "text": "blah", 
      "nodes": [ 
      { 
       "text": "foo", 
       "nodes": [ 
       { 
        "text": "new node", 
        "nodes": [] 
       } 
       ] 
      } 
      ] 
     } 
     ] 
    }, 
    { 
     "text": "blah", 
     "nodes": [] 
    }, 
    { 
     "text": "foo", 
     "nodes": [] 
    } 
    ] 
} 

Answer 3

你需要指定正確的路徑到「節點」數組。試試這個：

JObject json = JObject.Parse("{\"treeview\":[{\"text\":\"blah\",\"nodes\":[]},{\"text\":\"blah\",\"nodes\":[]},{\"text\":\"blah\",\"nodes\":[{\"text\":\"blah\",\"nodes\":[{\"text\":\"foo\",\"nodes\":[]}]}]},{\"text\":\"blah\",\"nodes\":[]},{\"text\":\"foo\",\"nodes\":[]}]}"); 
JArray array = (JArray)json.SelectToken("treeview[2].nodes[0].nodes[0].nodes"); 
array.Add(new JObject(new JProperty("text", "myValue")));