如何检索元素键值？

Question

I came across a problem, I need help to retrieve a certain key value when I scan the QR code, but for some reason I am retrieving the ID instead. However, I want to get the CandidateID instead. Can anyone help me solve this issue? thanks in advance.

JSON:

   {
    "ef4b0f54-e246-468b-ada9-465777c6e743": {    
        "CandiateID": "d9c4ba35-6c68-41de-b11c-f4226701c05a", // I want to retrieve  this when I scan the QR code. 
         "ID": "ef4b0f54-e246-468b-ada9-465777c6e743" // I am getting only this when I scan the QR Code.     
    }
} 

Answer 1

You are not getting the ID - You are reading the root value for the JSON. The values are aexactly the same so it only looks like you are reading the ID field.

When converting JSON to a dynamic object you can use the property indexers to access the correct value.

In your case you can use the following:

var results = JsonConvert.DeserializeObject<dynamic>(barCodeValue);

string id = results["ef4b0f54-e246-468b-ada9-465777c6e743"]["CandiateID"];

The first value is the root element of the JSON.

The second value is the field name within the JSON - CandiateID

The local variable id now contains the CandiateID property from the JSON.

Answer 2

You could use Linq for the purpose. For example

var jObject = JObject.Parse(barCodeValue);
var candidateID = jObject.Descendants()
                         .OfType<JProperty>()
                         .Where(x=>x.Name=="CandiateID")
                         .First().Value;

If there are more than one CandidateID to be fetched, you could use

var candidateIDs = jObject.Descendants()
                          .OfType<JProperty>()
                          .Where(x=>x.Name=="CandiateID")
                          .Select(x=>x.Value);