[Solved] Read Json from Url in ASP.Net Error: Sequence contains no elements

Hi kid.live,

Refer below sample.

HTML

<asp:GridView runat="server" ID="gvDetails" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="amount" HeaderText="Amount" />
        <asp:BoundField DataField="branch_num" HeaderText="Amount" />
        <asp:BoundField DataField="machineID" HeaderText="Machine" />
        <asp:BoundField DataField="shift" HeaderText="Shift" />
        <asp:BoundField DataField="userID" HeaderText="User" />
        <asp:BoundField DataField="voucher_date" HeaderText="Voucher Date" />
        <asp:BoundField DataField="voucher_number" HeaderText="Voucher Number" />
    </Columns>
</asp:GridView>

Namespaces

C#

using System.Collections.Generic;
using System.Net;
using Newtonsoft.Json;

VB.Net

Imports System.Collections.Generic
Imports System.Net
Imports Newtonsoft.Json

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.GetJsonData();
    }
}

public void GetJsonData()
{
    ServicePointManager.Expect100Continue = true;
    ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;
    string json = (new WebClient()).DownloadString("https://receipt-voucher-default-rtdb.firebaseio.com/receipts.json");
    Dictionary<string, object> values = JsonConvert.DeserializeObject<Dictionary<string, object>>(json);
    List<Receipt> receipts = new List<Receipt>();
    foreach (var entry in values)
    {
        receipts.Add(JsonConvert.DeserializeObject<Receipt>(entry.Value.ToString()));
    }
    gvDetails.DataSource = receipts;
    gvDetails.DataBind();
}

public class Receipt
{
    public string amount { get; set; }
    public string branch_num { get; set; }
    public string machineID { get; set; }
    public string shift { get; set; }
    public string userID { get; set; }
    public string voucher_date { get; set; }
    public string voucher_number { get; set; }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.GetJsonData()
    End If
End Sub

Public Sub GetJsonData()
    ServicePointManager.Expect100Continue = True
    ServicePointManager.SecurityProtocol = CType(3072, SecurityProtocolType)
    Dim json As String = (New WebClient()).DownloadString("https://receipt-voucher-default-rtdb.firebaseio.com/receipts.json")
    Dim values As Dictionary(Of String, Object) = JsonConvert.DeserializeObject(Of Dictionary(Of String, Object))(json)
    Dim receipts As List(Of Receipt) = New List(Of Receipt)()

    For Each entry In values
        receipts.Add(JsonConvert.DeserializeObject(Of Receipt)(entry.Value.ToString()))
    Next

    gvDetails.DataSource = receipts
    gvDetails.DataBind()
End Sub

Public Class Receipt
    Public Property amount As String
    Public Property branch_num As String
    Public Property machineID As String
    Public Property shift As String
    Public Property userID As String
    Public Property voucher_date As String
    Public Property voucher_number As String
End Class

Screenshot