[c#] json.net has key method?

If my response has key "error" I need to process error and show warning box.

Is there "haskey" method exists in json.net? Like:

var x= JObject.Parse(string_my);
if(x.HasKey["error_msg"])
    MessageBox.Show("Error!")

JObject implements IDictionary<string, JToken>, so you can use:

IDictionary<string, JToken> dictionary = x;
if (dictionary.ContainsKey("error_msg"))

... or you could use TryGetValue. It implements both methods using explicit interface implementation, so you can't use them without first converting to IDictionary<string, JToken> though.

JObject.ContainsKey(string propertyName) has been made as public method in 11.0.1 release

Documentation - https://www.newtonsoft.com/json/help/html/M_Newtonsoft_Json_Linq_JObject_ContainsKey.htm