Cannot deserialize the JSON array (e.g. [1,2,3]) into type ' ' because type requires JSON object (e.g. {"name":"value"}) to deserialize correctly
C#ArraysJsonSerializationjson.netC# Problem Overview
I have this JSON:
[ { "Attributes": [ { "Key": "Name", "Value": { "Value": "Acc 1", "Values": [ "Acc 1" ]
}
},
{
"Key": "Id",
"Value": {
"Value": "1",
"Values": [
"1"
]
}
}
],
"Name": "account",
"Id": "1"
},
{
"Attributes": [
{
"Key": "Name",
"Value": {
"Value": "Acc 2",
"Values": [
"Acc 2"
]
}
},
{
"Key": "Id",
"Value": {
"Value": "2",
"Values": [
"2"
]
}
}
],
"Name": "account",
"Id": "2"
},
{
"Attributes": [
{
"Key": "Name",
"Value": {
"Value": "Acc 3",
"Values": [
"Acc 3"
]
}
},
{
"Key": "Id",
"Value": {
"Value": "3",
"Values": [
"3"
]
}
}
],
"Name": "account",
"Id": "2"
}
]
And I have these classes:
public class RetrieveMultipleResponse
{
public List<Attribute> Attributes { get; set; }
public string Name { get; set; }
public string Id { get; set; }
}
public class Value
{
[JsonProperty("Value")]
public string value { get; set; }
public List<string> Values { get; set; }
}
public class Attribute
{
public string Key { get; set; }
public Value Value { get; set; }
}
I am trying to deserialize the above JSON using the code below:
var objResponse1 = JsonConvert.DeserializeObject<RetrieveMultipleResponse>(JsonStr);
but I am getting this error:
> Cannot deserialize the current JSON array (e.g. [1,2,3]) into type
> 'test.Model.RetrieveMultipleResponse' because the type requires a JSON
> object (e.g. {"name":"value"}) to deserialize correctly. To fix this
> error either change the JSON to a JSON object (e.g. {"name":"value"})
> or change the deserialized type to an array or a type that implements
> a collection interface (e.g. ICollection, IList) like List
C# Solutions
Solution 1 - C#
Your json string is wrapped within square brackets ([]
), hence it is interpreted as array instead of single RetrieveMultipleResponse
object. Therefore, you need to deserialize it to type collection of RetrieveMultipleResponse
, for example :
var objResponse1 =
JsonConvert.DeserializeObject<List<RetrieveMultipleResponse>>(JsonStr);
Solution 2 - C#
If one wants to support Generics (in an extension method) this is the pattern...
public static List<T> Deserialize<T>(this string SerializedJSONString)
{
var stuff = JsonConvert.DeserializeObject<List<T>>(SerializedJSONString);
return stuff;
}
It is used like this:
var rc = new MyHttpClient(URL);
//This response is the JSON Array (see posts above)
var response = rc.SendRequest();
var data = response.Deserialize<MyClassType>();
MyClassType looks like this (must match name value pairs of JSON array)
[JsonObject(MemberSerialization = MemberSerialization.OptIn)]
public class MyClassType
{
[JsonProperty(PropertyName = "Id")]
public string Id { get; set; }
[JsonProperty(PropertyName = "Name")]
public string Name { get; set; }
[JsonProperty(PropertyName = "Description")]
public string Description { get; set; }
[JsonProperty(PropertyName = "Manager")]
public string Manager { get; set; }
[JsonProperty(PropertyName = "LastUpdate")]
public DateTime LastUpdate { get; set; }
}
Use NUGET to download Newtonsoft.Json add a reference where needed...
using Newtonsoft.Json;
Solution 3 - C#
Can't add a comment to the solution but that didn't work for me. The solution that worked for me was to use:
> var des = (MyClass)Newtonsoft.Json.JsonConvert.DeserializeObject(response, typeof(MyClass)); > return des.data.Count.ToString();
https://stackoverflow.com/questions/5979434/deserializing-json-array-into-strongly-typed-net-object
Solution 4 - C#
Use this, FrontData
is JSON string:
var objResponse1 = JsonConvert.DeserializeObject<List<DataTransfer>>(FrontData);
and extract list:
var a = objResponse1[0];
var b = a.CustomerData;
Solution 5 - C#
To extract the first element (Key) try this method and it will be the same for the others :
using (var httpClient = new HttpClient())
{
using (var response = await httpClient.GetAsync("Your URL"))
{
var apiResponse = await response.Content.ReadAsStringAsync();
var list = JObject.Parse(apiResponse)["Attributes"].Select(el => new { Key= (string)el["Key"] }).ToList();
var Keys= list.Select(p => p.Key).ToList();
}
}
Solution 6 - C#
var objResponse1 =
JsonConvert.DeserializeObject<List<RetrieveMultipleResponse>>(JsonStr);
worked!