Question 264580 in Json Question posted in
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How to extract single value from array in Json string. This value is not a name>value pair

I have the below Json string. I need to use C# to return me "file_1.txt"

{
  "value": {
    "filenames": [
      "file_1.txt",
      "file_2.txt"
    ]
  }
}

I have tried Deserialize

        var myCustomclassname = Newtonsoft.Json.JsonConvert.DeserializeObject<dynamic>(json);
        var string1 = myCustomclassname.value;
        var string2 = myCustomclassname.filenames[0];

But it throws

"’Cannot perform runtime binding on a null reference

I have tried this

    JObject data = JObject.Parse(json);
    JToken filenamesToken = data.GetValue("filenames");
    List<string> filenames = JsonConvert.DeserializeObject<List<string>>(filenamesToken.ToString());

But it throws

‘Object reference not set to an instance of an object.’

Tags:

2

Answers


  1. 0

    Create a simple Class representation for the Json

    public class Root
{
    public Value value { get; set; }
}

public class Value
{
    public List<string> filenames { get; set; }
}

    Then use the JsonSerializer of your choice to deserialize the Json into the class and access the property you are interested in.

     var myLovelyRoot = JsonConvert.DeserializeObject<Root>(myLovelyJson);
 var fileName = myLovelyRoot.value.filenames.First();
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  2. 0

    In your first attempt (deserializing to dynamic), you’re looking for the filenames property in the root of the object:

    var string2 = myCustomclassname.filenames[0];

    But it’s not in the root of the object. It’s under the value property:

    var string2 = myCustomclassname.value.filenames[0];

    The same is true in your second attempt:

    JToken filenamesToken = data.GetValue("filenames");

    You’re missing the value property:

    JToken valueToken = data.GetValue("value");
JToken filenamesToken = valueToken["filenames"];
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