[Solved] ASP.Net Error: Json Value of type cannot be converted to System.Collections.Generic.List

Hi maideen,

Please refer below sample.

HTML

<asp:label ID="lblJsonData" runat="server"></asp:label>

Namespaces

C#

using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using System.Web.Script.Serialization;

VB.Net

Imports Newtonsoft.Json
Imports Newtonsoft.Json.Converters
Imports System.Web.Script.Serialization

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    List<Root> root = new List<Root>();

    PickupAddress PickupAddress = new PickupAddress()
    {
        name = "xxy Company LTD",
        address1 = "1, 11,13, Jalan Rajawali",
        address2 = "Bandar Puchong Jaya",
        city = "Puchong",
        country = "MY",
        district = "Puchong",
        state = "Selangor",
        postCode = "47000",
        email = "sales@xxy.com",
        phone = "069076 1651"
    };
    ShipperAddress shipperAddress = new ShipperAddress()
    {
        name = "xxy Company LTD",
        address1 = "1, 11,13, Jalan Rajawali",
        address2 = "Bandar Puchong Jaya",
        city = "Puchong",
        country = "MY",
        district = "Puchong",
        state = "Selangor",
        postCode = "47000",
        email = "sales@xxy.com",
        phone = "069076 1651"
    };
    ConsigneeAddress consignement = new ConsigneeAddress()
    {
        name = "Poliklinik Gunwant",
        address1 = "Lot 9797, Jalan Menteri",
        address2 = "Sungai Besar Selangor",
        city = "Sungai Besar",
        state = "Selangor",
        district = "Sungai Besar",
        country = "MY",
        postCode = "46000",
        email = "",
        phone = "092548 3257"
    };

    ValueAddedService valADDService = new ValueAddedService() { vasCode = "PPOD" };

    ValueAddedServices valueAddedServices = new ValueAddedServices() { valueAddedService = new List<ValueAddedService>() { valADDService } };

    List<ShipmentPiece> shipmentPieces = new List<ShipmentPiece>();
    shipmentPieces.Add(new ShipmentPiece() { pieceID = 1 });

    List<ShipmentItem> shipItem = new List<ShipmentItem>();
    shipItem.Add(new ShipmentItem()
    {
        consigneeAddress = consignement,
        shipmentID = "123456789",
        packageDesc = "abc",
        totalWeight = '1',
        totalWeightUOM = "KG",
        dimensionUOM = "CM",
        productCode = "PDO",
        currency = "USD",
        remarks = "",
        isMult = "true",
        deliveryOption = "C",
        shipmentPieces = shipmentPieces,
        valueAddedServices = valueAddedServices
    });

    Hdr hdr = new Hdr()
    {
        accessToken = "123456789",
        messageDateTime = new DateTime(2023, 01, 01, 11, 20, 27),
        messageLanguage = "en",
        messageType = "SHIPMENT",
        messageVersion = "1.4"
    };
    Bd bd = new Bd()
    {
        pickupAccountId = "123587",
        soldToAccountId = "325784",
        pickupDateTime = new DateTime(2023, 01, 01, 11, 20, 27),
        handoverMethod = '1',
        pickupAddress = PickupAddress,
        shipperAddress = shipperAddress,
        shipmentItems = shipItem
    };

    ManifestRequest manifesto = new ManifestRequest()
    {
        bd = bd,
        hdr = hdr
    };
    root.Add(new Root()
    {
        manifestRequest = manifesto
    });

    JavaScriptSerializer serializer = new JavaScriptSerializer();
    string v_jsonData = "";
    v_jsonData = serializer.Serialize(root);
    this.lblJsonData.Text = JsonConvert.SerializeObject(root, new IsoDateTimeConverter() { DateTimeFormat = "yyyy-MM-dd HH:mm:ss" });
}

public class Bd
{
    public string pickupAccountId { get; set; }
    public string soldToAccountId { get; set; }
    public DateTime pickupDateTime { get; set; }
    public int handoverMethod { get; set; }
    public PickupAddress pickupAddress { get; set; }
    public ShipperAddress shipperAddress { get; set; }
    public List<ShipmentItem> shipmentItems { get; set; }
}

public class ConsigneeAddress
{
    public string name { get; set; }
    public string address1 { get; set; }
    public string address2 { get; set; }
    public string city { get; set; }
    public string state { get; set; }
    public string district { get; set; }
    public string country { get; set; }
    public string postCode { get; set; }
    public string phone { get; set; }
    public string email { get; set; }
}

public class Hdr
{
    public string messageType { get; set; }
    public DateTime messageDateTime { get; set; }
    public string accessToken { get; set; }
    public string messageVersion { get; set; }
    public string messageLanguage { get; set; }
}

public class ManifestRequest
{
    public Hdr hdr { get; set; }
    public Bd bd { get; set; }
}

public class PickupAddress
{
    public string name { get; set; }
    public string address1 { get; set; }
    public string address2 { get; set; }
    public string city { get; set; }
    public string state { get; set; }
    public string district { get; set; }
    public string country { get; set; }
    public string postCode { get; set; }
    public string phone { get; set; }
    public string email { get; set; }
}

public class Root
{
    public ManifestRequest manifestRequest { get; set; }
}

public class ShipmentItem
{
    public ConsigneeAddress consigneeAddress { get; set; }
    public string shipmentID { get; set; }
    public string packageDesc { get; set; }
    public int totalWeight { get; set; }
    public string totalWeightUOM { get; set; }
    public string dimensionUOM { get; set; }
    public string productCode { get; set; }
    public string currency { get; set; }
    public string remarks { get; set; }
    public string isMult { get; set; }
    public string deliveryOption { get; set; }
    public List<ShipmentPiece> shipmentPieces { get; set; }
    public ValueAddedServices valueAddedServices { get; set; }
}

public class ValueAddedService
{
    public string vasCode { get; set; }
}

public class ValueAddedServices
{
    public List<ValueAddedService> valueAddedService { get; set; }
}

public class ShipmentPiece
{
    public int pieceID { get; set; }
}

public class ShipperAddress
{
    public string name { get; set; }
    public string address1 { get; set; }
    public string address2 { get; set; }
    public string city { get; set; }
    public string state { get; set; }
    public string district { get; set; }
    public string country { get; set; }
    public string postCode { get; set; }
    public string phone { get; set; }
    public string email { get; set; }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    Dim root As List(Of Root) = New List(Of Root)()
    Dim PickupAddress As PickupAddress = New PickupAddress() With {
        .name = "xxy Company LTD",
        .address1 = "1, 11,13, Jalan Rajawali",
        .address2 = "Bandar Puchong Jaya",
        .city = "Puchong",
        .country = "MY",
        .district = "Puchong",
        .state = "Selangor",
        .postCode = "47000",
        .email = "sales@xxy.com",
        .phone = "069076 1651"
    }
    Dim shipperAddress As ShipperAddress = New ShipperAddress() With {
        .name = "xxy Company LTD",
        .address1 = "1, 11,13, Jalan Rajawali",
        .address2 = "Bandar Puchong Jaya",
        .city = "Puchong",
        .country = "MY",
        .district = "Puchong",
        .state = "Selangor",
        .postCode = "47000",
        .email = "sales@xxy.com",
        .phone = "069076 1651"
    }
    Dim consignement As ConsigneeAddress = New ConsigneeAddress() With {
        .name = "Poliklinik Gunwant",
        .address1 = "Lot 9797, Jalan Menteri",
        .address2 = "Sungai Besar Selangor",
        .city = "Sungai Besar",
        .state = "Selangor",
        .district = "Sungai Besar",
        .country = "MY",
        .postCode = "46000",
        .email = "",
        .phone = "092548 3257"
    }
    Dim valADDService As ValueAddedService = New ValueAddedService() With {
        .vasCode = "PPOD"
    }
    Dim valueAddedServices As ValueAddedServices = New ValueAddedServices() With {
        .valueAddedService = New List(Of ValueAddedService)() From {
            valADDService
        }
    }
    Dim shipmentPieces As List(Of ShipmentPiece) = New List(Of ShipmentPiece)()
    shipmentPieces.Add(New ShipmentPiece() With {
        .pieceID = 1
    })
    Dim shipItem As List(Of ShipmentItem) = New List(Of ShipmentItem)()
    shipItem.Add(New ShipmentItem() With {
        .consigneeAddress = consignement,
        .shipmentID = "123456789",
        .packageDesc = "abc",
        .totalWeight = "1",
        .totalWeightUOM = "KG",
        .dimensionUOM = "CM",
        .productCode = "PDO",
        .currency = "USD",
        .remarks = "",
        .isMult = "true",
        .deliveryOption = "C",
        .shipmentPieces = shipmentPieces,
        .valueAddedServices = valueAddedServices
    })
    Dim hdr As Hdr = New Hdr() With {
        .accessToken = "123456789",
        .messageDateTime = New DateTime(2023, 1, 1, 11, 20, 27),
        .messageLanguage = "en",
        .messageType = "SHIPMENT",
        .messageVersion = "1.4"
    }
    Dim bd As Bd = New Bd() With {
        .pickupAccountId = "123587",
        .soldToAccountId = "325784",
        .pickupDateTime = New DateTime(2023, 1, 1, 11, 20, 27),
        .handoverMethod = "1",
        .pickupAddress = PickupAddress,
        .shipperAddress = shipperAddress,
        .shipmentItems = shipItem
    }
    Dim manifesto As ManifestRequest = New ManifestRequest() With {
        .bd = bd,
        .hdr = hdr
    }
    root.Add(New Root() With {
        .manifestRequest = manifesto
    })
    Dim serializer As JavaScriptSerializer = New JavaScriptSerializer()
    Dim v_jsonData As String = ""
    v_jsonData = serializer.Serialize(root)
    Me.lblJsonData.Text = JsonConvert.SerializeObject(root, New IsoDateTimeConverter() With {
        .DateTimeFormat = "yyyy-MM-dd HH:mm:ss"
    })
End Sub

Public Class Bd
    Public Property pickupAccountId As String
    Public Property soldToAccountId As String
    Public Property pickupDateTime As DateTime
    Public Property handoverMethod As Integer
    Public Property pickupAddress As PickupAddress
    Public Property shipperAddress As ShipperAddress
    Public Property shipmentItems As List(Of ShipmentItem)
End Class

Public Class ConsigneeAddress
    Public Property name As String
    Public Property address1 As String
    Public Property address2 As String
    Public Property city As String
    Public Property state As String
    Public Property district As String
    Public Property country As String
    Public Property postCode As String
    Public Property phone As String
    Public Property email As String
End Class

Public Class Hdr
    Public Property messageType As String
    Public Property messageDateTime As DateTime
    Public Property accessToken As String
    Public Property messageVersion As String
    Public Property messageLanguage As String
End Class

Public Class ManifestRequest
    Public Property hdr As Hdr
    Public Property bd As Bd
End Class

Public Class PickupAddress
    Public Property name As String
    Public Property address1 As String
    Public Property address2 As String
    Public Property city As String
    Public Property state As String
    Public Property district As String
    Public Property country As String
    Public Property postCode As String
    Public Property phone As String
    Public Property email As String
End Class

Public Class Root
    Public Property manifestRequest As ManifestRequest
End Class

Public Class ShipmentItem
    Public Property consigneeAddress As ConsigneeAddress
    Public Property shipmentID As String
    Public Property packageDesc As String
    Public Property totalWeight As Integer
    Public Property totalWeightUOM As String
    Public Property dimensionUOM As String
    Public Property productCode As String
    Public Property currency As String
    Public Property remarks As String
    Public Property isMult As String
    Public Property deliveryOption As String
    Public Property shipmentPieces As List(Of ShipmentPiece)
    Public Property valueAddedServices As ValueAddedServices
End Class

Public Class ValueAddedService
    Public Property vasCode As String
End Class

Public Class ValueAddedServices
    Public Property valueAddedService As List(Of ValueAddedService)
End Class

Public Class ShipmentPiece
    Public Property pieceID As Integer
End Class

Public Class ShipperAddress
    Public Property name As String
    Public Property address1 As String
    Public Property address2 As String
    Public Property city As String
    Public Property state As String
    Public Property district As String
    Public Property country As String
    Public Property postCode As String
    Public Property phone As String
    Public Property email As String
End Class

Generated json

[
  {
    "manifestRequest": {
      "hdr": {
        "messageType": "SHIPMENT",
        "messageDateTime": "2023-01-01 11:20:27",
        "accessToken": "123456789",
        "messageVersion": "1.4",
        "messageLanguage": "en"
      },
      "bd": {
        "pickupAccountId": "123587",
        "soldToAccountId": "325784",
        "pickupDateTime": "2023-01-01 11:20:27",
        "handoverMethod": 49,
        "pickupAddress": {
          "name": "xxy Company LTD",
          "address1": "1, 11,13, Jalan Rajawali",
          "address2": "Bandar Puchong Jaya",
          "city": "Puchong",
          "state": "Selangor",
          "district": "Puchong",
          "country": "MY",
          "postCode": "47000",
          "phone": "069076 1651",
          "email": "sales@xxy.com"
        },
        "shipperAddress": {
          "name": "xxy Company LTD",
          "address1": "1, 11,13, Jalan Rajawali",
          "address2": "Bandar Puchong Jaya",
          "city": "Puchong",
          "state": "Selangor",
          "district": "Puchong",
          "country": "MY",
          "postCode": "47000",
          "phone": "069076 1651",
          "email": "sales@xxy.com"
        },
        "shipmentItems": [
          {
            "consigneeAddress": {
              "name": "Poliklinik Gunwant",
              "address1": "Lot 9797, Jalan Menteri",
              "address2": "Sungai Besar Selangor",
              "city": "Sungai Besar",
              "state": "Selangor",
              "district": "Sungai Besar",
              "country": "MY",
              "postCode": "46000",
              "phone": "092548 3257",
              "email": ""
            },
            "shipmentID": "123456789",
            "packageDesc": "abc",
            "totalWeight": 49,
            "totalWeightUOM": "KG",
            "dimensionUOM": "CM",
            "productCode": "PDO",
            "currency": "USD",
            "remarks": "",
            "isMult": "true",
            "deliveryOption": "C",
            "shipmentPieces": [
              {
                "pieceID": 1
              }
            ],
            "valueAddedServices": {
              "valueAddedService": [
                {
                  "vasCode": "PPOD"
                }
              ]
            }
          }
        ]
      }
    }
  }
]

AjayV says:

this.lblJsonData.Text = JsonConvert.SerializeObject(root, new IsoDateTimeConverter() { DateTimeFormat = "yyyy-MM-dd HH:mm:ss" });

Change the DateFormat with yyyy-MM-dd'T'HH:mm:sszzz.

this.lblJsonData.Text = JsonConvert.SerializeObject(root, new IsoDateTimeConverter() { DateTimeFormat = "yyyy-MM-dd'T'HH:mm:sszzz" });