The have an issue where I am unable to call nested JSON Objects from a scraped website. The scraping process works prefectly, but the JSON Serializing part is the only issue. My code is shown below:
private void GetHtmlAsync()
{
var url = "https://opentdb.com/api.php?amount=10";
var httpClient = new HttpClient();
var html = httpClient.GetStringAsync(url);
DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(typeof(MyDetail));
MemoryStream stream = new MemoryStream(Encoding.UTF8.GetBytes(html.Result));
stream.Position = 0;
MyDetail dataContractDetail = (MyDetail) jsonSerializer.ReadObject(stream);
text.text = "" + dataContractDetail.results[1];
//text.text = string.Concat("Test: ", dataContractDetail.question, " " + dataContractDetail.correct_answer);
}
public class MyDetail
{
[DataMember]
public Dictionary<string, questions> results
{
get;
set;
}
public class questions
{
public string question { get; set; }
public string correct_answer { get; set; }
}
[DataMember]
public string response_code
{
get;
set;
}
}
This code is the code that does not work, in that I try to call the first object in results by doing "results[1]", which returns an error after I attach, say, "question" to it by doing "results[1].question". This syntax seems reasonable, so I don;t understand why it is not working. My JSON File is shown below:
{
"response_code": 0,
"results": [
{
"category": "Entertainment: Video Games",
"type": "multiple",
"difficulty": "medium",
"question": "What is the name of the virus in "Metal Gear Solid 1"?",
"correct_answer": "FOXDIE",
"incorrect_answers": [
"FOXENGINE",
"FOXALIVE",
"FOXKILL"
]
},
{
"category": "Geography",
"type": "multiple",
"difficulty": "easy",
"question": "What is the official language of Costa Rica?",
"correct_answer": "Spanish",
"incorrect_answers": [
"English",
"Portuguese",
"Creole"
]
},
{
"category": "Entertainment: Video Games",
"type": "multiple",
"difficulty": "medium",
"question": "In Fallout 4, which type of power armor is first encountered in the early mission "When Freedom Calls" in a crashed Vertibird?",
"correct_answer": "T-45",
"incorrect_answers": [
"T-51",
"T-60",
"X-01"
]
},
{
"category": "Politics",
"type": "boolean",
"difficulty": "medium",
"question": "George W. Bush lost the popular vote in the 2004 United States presidential election.",
"correct_answer": "False",
"incorrect_answers": [
"True"
]
},
{
"category": "Entertainment: Video Games",
"type": "multiple",
"difficulty": "medium",
"question": "In "Halo 2", what is the name of the monitor of Installation 05?",
"correct_answer": "2401 Penitent Tangent",
"incorrect_answers": [
"343 Guilty Spark",
"031 Exuberant Witness",
"252 Biodis Expolsion"
]
},
{
"category": "Entertainment: Books",
"type": "multiple",
"difficulty": "medium",
"question": "The book "Fahrenheit 451" was written by whom?",
"correct_answer": "Ray Bradbury",
"incorrect_answers": [
"R. L. Stine",
"Wolfgang Amadeus Mozart",
"Stephen King"
]
},
{
"category": "Entertainment: Cartoon & Animations",
"type": "multiple",
"difficulty": "hard",
"question": "In "Rick and Morty", from which dimension do Rick and Morty originate from?",
"correct_answer": "C-137",
"incorrect_answers": [
"J1977",
"C-136",
"C500-a"
]
},
{
"category": "Entertainment: Video Games",
"type": "multiple",
"difficulty": "hard",
"question": "In which game did the character "Mario" make his first appearance?",
"correct_answer": "Donkey Kong",
"incorrect_answers": [
"Super Mario Bros.",
"Super Mario Land",
"Mario Bros."
]
},
{
"category": "Entertainment: Film",
"type": "multiple",
"difficulty": "hard",
"question": "What was Humphrey Bogart's middle name?",
"correct_answer": "DeForest",
"incorrect_answers": [
"DeWinter",
"Steven",
"Bryce"
]
},
{
"category": "Entertainment: Cartoon & Animations",
"type": "boolean",
"difficulty": "medium",
"question": "In "Avatar: The Last Airbender" and "The Legend of Korra", Lavabending is a specialized bending technique of Firebending.",
"correct_answer": "False",
"incorrect_answers": [
"True"
]
}
]
}
There are many issues in your code. I don't know all the libraries you are using but here is how I would do it.
First of all you start a GetStringAsync but you continue immediately without waiting for results. I don't know all the libraries you are using ofcourse maybe it is supposed to be like that?
However I would rather use Unity's UnityWebRequest.Get
private void GetHtmlAsync()
{
StartCoroutine(DownloadJson());
}
private IEnumerator DownloadJson()
{
var url = "https://opentdb.com/api.php?amount=10";
using(var uwr = UnityWebRequest.Get(url))
{
// send the request and wait for result
yield return uwr.SendWebRequest();
// Check for success!
if(uwr.isNetworkError || uwr.isHttpError || !string.IsNullOrWhiteSpace(uwr.error))
{
Debug.LogError($"Download failed with {uwr.responseCode} reason: {uwr.error}", this);
yield break;
}
var json = uwr.DownloadHandler.text;
// ... se below
}
}
Again I don't know your JSON library but your class seems not to match the JSON data structure which would be (by simply jamming it through json2csharp)
[Serializable]
public class Result
{
public string category;
public string type;
public string difficulty;
public string question;
public string correct_answer;
public List<string> incorrect_answers;
}
[Serializable]
public class MyDetail
{
public int response_code;
public List<Result> results;
}
for Unity I would use [Serializable] and also remove all the {get;set} in order to not use properties but fields.
Then you could simply use Unity's JsonUtility
...
MyDetail dataContractDetail = JsonUtility.FromJson<MyDetail>(json);
Then as mentioned in the comments note that array indices in c# are 0-based so the first element would be
var firstResult = dataContractDetail.results[0];
Now the question is what do you want to see on your text? The firstResult is no string but rather a class having various members! You could e.g. want to display the question like
text.text = firstResult.question;