[Solved] jQuery DataTable Error: Property without a Readonly or write only specifier must provide both Get and a Set

Hi firasataries

Refer below sample code.

Customer Class

Public Class Customer
    Private _customerID As String
    Public Property CustomerID() As String
        Get
            Return _customerID
        End Get
        Set(ByVal value As String)
            _customerID = value
        End Set
    End Property

    Private _contactName As String
    Public Property ContactName() As String
        Get
            Return _contactName
        End Get
        Set(ByVal value As String)
            _contactName = value
        End Set
    End Property

    Private _city As String
    Public Property City() As String
        Get
            Return _city
        End Get
        Set(ByVal value As String)
            _city = value
        End Set
    End Property

    Private _country As String
    Public Property Country() As String
        Get
            Return _country
        End Get
        Set(ByVal value As String)
            _country = value
        End Set
    End Property
End Class

HTML

<div style="width: 500px">
    <asp:GridView ID="gvCustomers" runat="server" CssClass="display compact" AutoGenerateColumns="false">
        <Columns>
            <asp:BoundField DataField="CustomerID" HeaderText="Customer Id" />
            <asp:BoundField DataField="ContactName" HeaderText="Name" />
            <asp:BoundField DataField="City" HeaderText="City" />
            <asp:BoundField DataField="Country" HeaderText="Country" />
        </Columns>
    </asp:GridView>
</div>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript" src="https://cdn.datatables.net/1.10.20/js/jquery.dataTables.min.js"></script>
<link href="https://cdn.datatables.net/1.10.20/css/jquery.dataTables.css" rel="stylesheet"
    type="text/css" />
<script type="text/javascript">
    $(function () {
        $.ajax({
            type: "POST",
            url: "Default.aspx/GetCustomers",
            data: '{}',
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: OnSuccess,
            failure: function (response) {
                alert(response.d);
            },
            error: function (response) {
                alert(response.d);
            }
        });
    });
    function OnSuccess(response) {
        $("[id*=gvCustomers]").DataTable({
            bLengthChange: true,
            lengthMenu: [[5, 10, -1], [5, 10, "All"]],
            bFilter: true,
            bSort: true,
            bPaginate: true,
            data: response.d,
            columns: [{ 'data': 'CustomerID' },
                { 'data': 'ContactName' },
                { 'data': 'City' },
                { 'data': 'Country'}]
        });
    };
</script>

Code

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dummy As DataTable = New DataTable()
        dummy.Columns.Add("CustomerID")
        dummy.Columns.Add("ContactName")
        dummy.Columns.Add("City")
        dummy.Columns.Add("Country")
        dummy.Rows.Add()
        gvCustomers.DataSource = dummy
        gvCustomers.DataBind()
        gvCustomers.UseAccessibleHeader = True
        gvCustomers.HeaderRow.TableSection = TableRowSection.TableHeader
    End If
End Sub

<WebMethod()>
Public Shared Function GetCustomers() As List(Of Customer)
    Dim customers As List(Of Customer) = New List(Of Customer)()
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(constr)
        Using cmd As SqlCommand = New SqlCommand("SELECT CustomerID, ContactName, City, Country FROM Customers", con)
            con.Open()
            Using sdr As SqlDataReader = cmd.ExecuteReader()
                While sdr.Read()
                    customers.Add(New Customer With {
                        .CustomerID = sdr("CustomerID").ToString(),
                        .ContactName = sdr("ContactName").ToString(),
                        .City = sdr("City").ToString(),
                        .Country = sdr("Country").ToString()
                    })
                End While
            End Using
            con.Close()
        End Using
    End Using
    Return customers
End Function

Screenshot