class Program
{
private static readonly HttpClient client = new HttpClient();
static void Main(string[] args)
{
var cats = ProcessCats().Result;
foreach (var cat in cats)
{
Console.WriteLine(cat);
Console.WriteLine();
}
}
private static async Task<Cat[]> ProcessCats()
{
client.DefaultRequestHeaders.Accept.Clear();
//...
var stream = await client.GetStreamAsync("https://myapi/cats");
var serializerSettings = new JsonApiSerializerSettings();
var serializer = JsonSerializer.CreateDefault(serializerSettings);
using (var textReader = new StreamReader(stream))
using (var jsonReader = new JsonTextReader(textReader))
return serializer.Deserialize<Cat[]>(jsonReader);
}
}
public class Cat
{
public string Name { get; set; }
public override string ToString()
{
var sb = new StringBuilder();
sb.Append("class Cat {\n");
sb.Append(" Name: ").Append(Name).Append("\n");
sb.Append("}\n");
return sb.ToString();
}
}
Error
Unhandled Exception: System.AggregateException: One or more errors occurred. (Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'Cat[]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.
To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List
Path 'data', line 1, position 8.) ---> Newtonsoft.Json.JsonSerializationException: Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'Cat[]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.
To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List
Path 'data', line 1, position 8.
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
at Newtonsoft.Json.JsonSerializer.Deserialize[T](JsonReader reader)
at WebAPIClient.Program.ProcessCats() in /Users/esteban-work/tmp/delete/samples/csharp/getting-started/console-webapiclient/Program.cs:line 42
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
at WebAPIClient.Program.Main(String[] args) in /Users/esteban-work/tmp/delete/samples/csharp/getting-started/console-webapiclient/Program.cs:line 17
Fix
Remember to check if the root element has an Id property.
public class Cat
{
public string Id { get; set; }
public string Name { get; set; }
public override string ToString()
{
var sb = new StringBuilder();
sb.Append("class ContactForClient {\n");
sb.Append(" Id: ").Append(Id).Append("\n");
sb.Append(" Name: ").Append(Name).Append("\n");
sb.Append("}\n");
return sb.ToString();
}
}
References
