无法反序列化当前的JSON对象

Question

Cannot De-Serialize the current JSON object (eg {"name":"value"} ) into type 'System.Collections.Generic.List 1[NIPRA.Models.OrderHeaderResult]' because the type requires a JSON array (eg [1,2,3])` to De-Serialize correctly.

To fix this error either change the JSON to a JSON array (eg [1,2,3]) or change the De-Serialized type so that it is a normal .NET type (eg not a primitive type like integer , not a collection type like an array or List) that can be De-Serialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to De-Serialize from a JSON object.

Path 'Orders', line 1, position 10.

Json data:

{"Orders":
[{"Id":397908,
"BuyerId":1831,
"DateCreated":"2016-02-16T10:58:55",
"DateUpdated":"2016-02-16T10:58:55",
"DeliveryDate":"2015-01-20T00:00:00",
"UploadDate":"2016-02-16T10:58:55",
"InvoiceToName":"Lancet Laboratories (Pty) Ltd",
"OrderDate":"2016-02-16T08:58:55",
"OrderNumber":"PTYPO000006",
"OrderStatusId":1,
"OrderTotal":42050.3500,
"OrderTypeId":2,
"PartnerId":"V0002066  ",
"SupplierAccountName":"Bio-Rad Laboratories (Pty) Ltd",
"SupplierId":1696,
"ShipToName":"Rich Corn",
"SystemOrderStatusId":1,
"TermsOfPayment":"30DS",
"Supplier":null,
"Buyer":"Lancet Laboratories",
"BuyerName":"juri.vdv",
"BuyerAccountNumber":"",
"OrderStatus":"Requested",
"OrderType":"PURCHASE",
"HasComments":"No",
"TotalExcludingVAT":36886.2700,
"VATAmount":5164.0800,"AmendedBy":"System",
"FileName":""}],
"TotalPages":2}

---

My viewmodel:

public partial class OrderHeaderView
{
    [JsonProperty("id")]
    public int Id { get; set; }
    [JsonProperty("buyerId")]
    public int BuyerId { get; set; }
    [JsonProperty("dateCreated")]
    public System.DateTime DateCreated { get; set; }
    [JsonProperty("dateUpdated")]
    public System.DateTime DateUpdated { get; set; }
    [JsonProperty("deliveryDate")]
    public Nullable<System.DateTime> DeliveryDate { get; set; }
    [JsonProperty("uploadDate")]
    public Nullable<System.DateTime> UploadDate { get; set; }
    [JsonProperty("invoiceToName")]
    public string InvoiceToName { get; set; }
    [JsonProperty("orderDate")]
    public Nullable<System.DateTime> OrderDate { get; set; }
    [JsonProperty("orderNumber")]
    public string OrderNumber { get; set; }
    [JsonProperty("orderStatusId")]
    public int OrderStatusId { get; set; }
    [JsonProperty("orderTotal")]
    public decimal OrderTotal { get; set; }
    [JsonProperty("orderTypeId")]
    public int OrderTypeId { get; set; }
    [JsonProperty("partnerId")]
    public string PartnerId { get; set; }
    [JsonProperty("supplierAccountName")]
    public string SupplierAccountName { get; set; }
    [JsonProperty("supplierId")]
    public int SupplierId { get; set; }
    [JsonProperty("shipToName")]
    public string ShipToName { get; set; }
    [JsonProperty("systemOrderStatusId")]
    public Nullable<int> SystemOrderStatusId { get; set; }
    [JsonProperty("termsOfPayment")]
    public string TermsOfPayment { get; set; }
    [JsonProperty("supplier")]
    public string Supplier { get; set; }
    [JsonProperty("buyer")]
    public string Buyer { get; set; }
    [JsonProperty("buyerName")]
    public string BuyerName { get; set; }
    [JsonProperty("buyerAccountNumber")]
    public string BuyerAccountNumber { get; set; }
    [JsonProperty("orderStatu")]
    public string OrderStatus { get; set; }
    [JsonProperty("orderType")]
    public string OrderType { get; set; }
    [JsonProperty("hasComments")]
    public string HasComments { get; set; }
    [JsonProperty("totalExcludingVAT")]
    public decimal TotalExcludingVAT { get; set; }
    [JsonProperty("vatAmount")]
    public decimal VATAmount { get; set; }
    [JsonProperty("amendedBy")]
    public string AmendedBy { get; set; }
    [JsonProperty("fileName")]
    public string FileName { get; set; }
    [JsonProperty("hasDelivery")]
    public bool HasDelivery { get; set; }
}

---

RootObject model:

public class OrderHeaderResult
{
    public int TotalPages { get; set; }
    public OrderHeaderView[] Orders { get; set; }
}

---

public async Task<List<OrderHeaderResult>> GetOrders(int statusId, int page, string keyword, int year)

    {
        _client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("bearer", UserToken.AccessToken);
        var result = await _client.GetAsync($"api/invoicing/getorders?statusId={statusId}&page={page}&keyword={keyword}&year={year}");
        if (result.IsSuccessStatusCode)
        {
            var orderData = await result.Content.ReadAsStringAsync();

            return JsonConvert.DeserializeObject<List<OrderHeaderResult>>(orderData);    

        }
        else
            return null;
    }

---

controller:

    [HttpGet]
    public async Task<ActionResult> Index(int? id, int?page, string keyword, int?year)
    {
        _orderService.UserToken = base.Token;

        var orders = await  _orderService.GetOrders(id??1,page??2,keyword,year??DateTime.Now.Year);
         return View(orders);

    }

please help and how to display this on razor view ?

Answer 1

Your JSON definitely does not look like a collection.
You have a single JSON object, which is properly described in OrderHeaderResult class.

Try changing

JsonConvert.DeserializeObject<List<OrderHeaderResult>>(orderData);

to

JsonConvert.DeserializeObject<OrderHeaderResult>(orderData);