I got a JSON string with an array like this:
{
"Id": 123,
"Username": "Sr. X",
"Packages": [
{
"Name": "Cups",
"SupplierId": 1,
"ProviderGroupId": 575,
"SupplierName": "Foo Cups"
},
{
"Name": "Pins",
"SupplierId": 5,
"ProviderGroupId": 1082,
"SupplierName": "Foo Pins"
}
]
}
"Packages": [
{
"Name": "Cups",
"SupplierId": 1,
"ProviderGroupId": 575,
"SupplierName": "Foo Cups",
"New Field": "Value"
},...
JObject implemets IDictionary.
var jObj = JObject.Parse(json);
foreach(var item in jObj["Packages"])
{
item["New Field"] = "Value";
}
var newjson = jObj.ToString(Newtonsoft.Json.Formatting.Indented);