How do I deserialize this JSON file? RSS

• • Reply
  Piornet

  Member

  15 Points

  74 Posts

  How do I deserialize this JSON file?

  Aug 16, 2019 04:12 PM|Piornet|LINK

  Hi all,

  Please forgive the newbie question, but I'm having trouble deserializing a JSON collection and I all the examples I've found don't seem to work for my scenario.  

  When attempting to deserialize this file, I only get NULLs in return.  Here's the file:

  {
    "elements": [
      {
        "name": "Elements",
        "items": [
          {
            "name": "input text",
            "icon": "fa fa-text-width",
            "content": "elements/input-text.html"
          },
          {
            "name": "input date",
            "icon": "fa fa-calendar",
            "content": "elements/input-date.html"
          },
          {
            "name": "textarea",
            "icon": "fa fa-pencil-square-o",
            "content": "elements/input-textarea.html"
          },
          {
            "name": "input number",
            "icon": "fa fa-sort-numeric-asc",
            "content": "elements/input-number.html"
          },
          {
            "name": " input email",
            "icon": "fa fa-envelope ",
            "content": "elements/input-email.html"
          },
          {
            "name": "file",
            "icon": "fa fa-cloud-upload",
            "content": "elements/input-file.html"
          },
          {
            "name": "checkbox",
            "icon": "fa fa-check ",
            "content": "elements/input-checkbox.html"
          },
          {
            "name": "select",
            "icon": "fa fa-chevron-circle-down ",
            "content": "elements/input-select.html"
          },
          {
            "name": "radio",
            "icon": "fa fa-check-circle ",
            "content": "elements/input-radio.html"
          },
          {
            "name": "Heading",
            "icon": "fa fa-header ",
            "content": "elements/heading.html"
          },
          {
            "name": "paragraph",
            "icon": "fa fa-paragraph",
            "content": "elements/paragraph.html"
          },
          {
            "name": "Divider",
            "icon": "fa fa-minus ",
            "content": "elements/divider.html"
          }
        ]
      }
    ]
  
  }
  

  And here's my code:

  List<Element> jsonElements = new List<Element>();            
  
  //Get the list of elements
  using (StreamReader file = File.OpenText(Server.MapPath(elementsDictionary)))
       {
            JsonSerializer serializer = new JsonSerializer();
            jsonElements.Add((Element)serializer.Deserialize(file, typeof(Element)));
       }
  
  //Loop through each element, build the menu selector for it
  foreach (var element in jsonElements)
       {
            //Do stuff here
       }
  

  public class Element
       {
           public string name { get; set; }
           public string icon { get; set; }
           public string content { get; set; }
       }

  Could anyone tell me what obvious dumb thing I'm doing wrong?  I'd greatly greatly appreciate it.

  Thanks in advance!

• • Reply
  mgebhard

  All-Star

  52261 Points

  23315 Posts

  Re: How do I deserialize this JSON file?

  Aug 17, 2019 11:17 AM|mgebhard|LINK

  The  C# class does not match the JSON format.  Use Visual Studio to create classes.  Copy the JSON, then in Visual Studio click Edit -> Paste Special -> Paste JSON as Classes.

      public class Element
      {
          public string name { get; set; }
          public Item[] items { get; set; }
      }
  
      public class Item
      {
          public string name { get; set; }
          public string icon { get; set; }
          public string content { get; set; }
      }

  You're deserializing a collection.  

  Element[] elements

  Or 

  List<Element> elements

  https://www.newtonsoft.com/json/help/html/SerializingJSON.htm

• • Reply
  Yongqing Yu

  Contributor

  3710 Points

  1043 Posts

  Re: How do I deserialize this JSON file?

  Aug 19, 2019 03:32 AM|Yongqing Yu|LINK

  Hi Piornet.

  According to your description, I found that your json text file contains hierarchical relationships, and that's why you didn't get value in jsonElements.

  In this case, you need to use the dynamic type to accept your deserialized data.

  Here is the code:

            List<Element> jsonElements = new List<Element>();
  
                  //Get the list of elements
                  using (StreamReader file = File.OpenText(Server.MapPath(elementsDictionary)))
                  {
                      dynamic stuff = JsonConvert.DeserializeObject(File.ReadAllText(Server.MapPath(elementsDictionary)));
                      for (int i = 0; i < stuff.elements[0].items.Count; i++)
                      {
                          Element element = new Element();
                          element.name = stuff.elements[0].items[i].name;
                          element.icon = stuff.elements[0].items[i].icon;
                          element.content = stuff.elements[0].items[i].content;
                          jsonElements.Add(element);
                      }
                  }

  You can also refer to this link : Deserialize JSON into C# dynamic object?

  Best Regards,

  YongQing.

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