Convert json string to C#

You should consider a JSON parser and use it to convert that JSON document to a runtime object, JSON.NET would work in this case. Json.NET - Newtonsoft[^]. These parsers would convert your documents properly, without having to worry about invalid data (and if the document is invalid, it would throw exception). Have a look at the JSON schema validator, JSON Schema Validator - Newtonsoft[^], and then try to parse that value in any online JavaScript based JSON parser (JSON.parse()) and you can see for yourself. Are you using your own build parser? The following is a JavaScript sample for this, Edit fiddle - JSFiddle[^]

(function() {
    alert(
    JSON.parse("{\"@odata.context\":\"http://192.168.0.126:49540/odata/$metadata#Edm.String\",\"value\":\"The Chinese Stai\"}")
    .value);
})();

Now as for C#, the code to do that would be,

// You need to use dynamic as type of returned object
// data is that string
dynamic obj = JsonConvert.DeserializeObject(data);

Console.WriteLine(obj.value); // Prints: The Chinese Stai

If everything goes right, you will see that output. I wrote an article on the topic of JSON and C#, you should consider reading that, From zero to hero in JSON with C#[^]. It also explains the process of extracting dynamically built JSON documents in dynamic objects in C#, see the comments to that article.