I'm new to JSON.NET, and I need help to deserialize the following JSON
{
"items": [
[10, "file1", "command 1"],
[20, "file2", "command 2"],
[30, "file3", "command 3"]
]
}
to this
IList<Item> Items {get; set;}
class Item
{
public int Id {get; set}
public string File {get; set}
public string Command {get; set}
}
The content in the JSON is always in the same order.
You can use a custom JsonConverter to convert each child array in the JSON to an Item. Here is the code you would need for the converter:
class ItemConverter : JsonConverter
{
public override bool CanConvert(Type objectType)
{
return (objectType == typeof(Item));
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
JArray array = JArray.Load(reader);
return new Item
{
Id = (int)array[0],
File = (string)array[1],
Command = (string)array[2]
};
}
public override bool CanWrite
{
get { return false; }
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
throw new NotImplementedException();
}
}
With the above converter, you can deserialize into your classes easily as demonstrated below:
class Program
{
static void Main(string[] args)
{
string json = @"
{
""items"": [
[10, ""file1"", ""command 1""],
[20, ""file2"", ""command 2""],
[30, ""file3"", ""command 3""]
]
}";
Foo foo = JsonConvert.DeserializeObject<Foo>(json, new ItemConverter());
foreach (Item item in foo.Items)
{
Console.WriteLine("Id: " + item.Id);
Console.WriteLine("File: " + item.File);
Console.WriteLine("Command: " + item.Command);
Console.WriteLine();
}
}
}
class Foo
{
public List<Item> Items { get; set; }
}
class Item
{
public int Id { get; set; }
public string File { get; set; }
public string Command { get; set; }
}
Output:
Id: 10
File: file1
Command: command 1
Id: 20
File: file2
Command: command 2
Id: 30
File: file3
Command: command 3
Fiddle: https://dotnetfiddle.net/RXggvl
For deserialization your JSON should be like this
{
"items": [
{Id: 10, File: "file1", Command: "command 1"},
{Id: 20, File: "file2", Command: "command 2"},
{Id: 30, File: "file3", Command: "command 3"}
]
}
This will map the variables Id, File and Command to properties Id, File and Command respectively during deserialization
You can deserialize it using the following code
public List<Item> DeserializeJSON(string jsonString)
{
DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(List<Item>));
MemoryStream stream = new MemoryStream(Encoding.UTF8.GetBytes(jsonString));
var obj = (List<Item>)ser.ReadObject(stream);
return obj;
}
You can do this by using an intermediate type to capture the conversion from Json and the map that to your Item class afterwards. So first we have the intermediate class:
public class IntermediateType
{
public object[][] items { get; set; }
}
And now we can get your results like this:
var json = "{\"items\": [ [10, \"file1\", \"command 1\"], [20, \"file2\", \"command 2\"], [30, \"file3\", \"command 3\"] ]}";
var result = JsonConvert
.DeserializeObject<IntermediateType>(json)
.items
.Select(o => new Item
{
Id = int.Parse(o[0].ToString()),
File = (string)o[1],
Command = (string)o[2]
});
doubles, there's cases that the DeserializeObject will change what should be a double into an int. Then when we try casting the object to double, we get cast exceptions.