In this article I will explain with an example, how to read (parse) JSON data from URL and display in ASP.Net DataList using C# and VB.Net.
 
 

Download JSON.Net library

The JSON.Net library is available for download from the following URL.
Download JSON.Net
 

JSON File URL

This article uses the following REST API hosted on GitHub.
https://raw.githubusercontent.com/aspsnippets/test/master/Customers.json
The following JSON string is returned from the API.
[
 {
    "CustomerId": 1,
    "Name": "John Hammond",
    "Country": "United States"
 },
 {
    "CustomerId": 2,
    "Name": "Mudassar Khan",
    "Country": "India"
 },
 {
    "CustomerId": 3,
    "Name": "Suzanne Mathews",
    "Country": "France"
 },
 {
    "CustomerId": 4,
    "Name": "Robert Schidner",
    "Country": "Russia"
 }
]
 
 

HTML Markup

The following HTML Markup consists of:
DataList – For displaying data.

Templates

HeaderTemplate – The content of this template will not be repeated and will be placed in the top most position i.e. head section of the DataList control.
ItemTemplate – The content of this template will be repeated for each record present in its DataSource.
FooterTemplate – The content of this template will not be repeated and will be placed in the bottom most position i.e. footer section of the DataList control.
 

Controls

ItemTemplate consists of three Label control for displaying CustomerId, Name and Country of Customers.
<asp:DataList ID="dlCustomers" runat="server">
    <HeaderTemplate>
        <table class="Grid">
            <tr>
                <th>Customer Id</th>
                <th>Name</th>
                <th>Country</th>
            </tr>
    </HeaderTemplate>
    <ItemTemplate>
        <tr>
            <td><asp:Label runat="server" Text='<%# Eval("CustomerId") %>'></asp:Label></td>
            <td><asp:Label runat="server" Text='<%# Eval("Name") %>'></asp:Label></td>
            <td><asp:Label runat="server" Text='<%# Eval("Country") %>'></asp:Label></td>
        </tr>
    </ItemTemplate>
    <FooterTemplate>
        </table>
    </FooterTemplate>
</asp:DataList>
 
 

Namespaces

You will need to import the following namespaces.
C#
using System.Net;
using System.Data;
using Newtonsoft.Json;
 
VB.Net
Imports System.Net
Imports System.Data
Imports Newtonsoft.Json
 
 

Reading (Parsing) JSON data from URL and display in ASP.Net DataList

Inside the Page Load event handler, first the Security Protocol is set.
Note: For higher .Net Framework version 4.5 and above, please refer Using TLS1.2 with HttpClient in C# and VB.Net.
 
The JSON string is downloaded from an API using DownloadString method of the WebClient class.
DownloadString:
It accepts the following parameter:
URL – The URL of the file to be downloaded.
The downloaded JSON string is then converted to DataTable using DeserializeObject method of JsonConvert class.
Finally, the DataTable is assigned to the DataSource property of the DataList and the DataList is populated.
C#
protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        ServicePointManager.Expect100Continue = true;
        ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;
        string json = (new WebClient()).DownloadString("https://raw.githubusercontent.com/aspsnippets/test/master/Customers.json");
        dlCustomers.DataSource = JsonConvert.DeserializeObject<DataTable>(json);
        dlCustomers.DataBind();
    }
}
 
VB.Net
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        ServicePointManager.Expect100Continue = True
        ServicePointManager.SecurityProtocol = CType(3072, SecurityProtocolType)
        Dim json As String = (New WebClient()).DownloadString("https://raw.githubusercontent.com/aspsnippets/test/master/Customers.json")
        dlCustomers.DataSource = JsonConvert.DeserializeObject(Of DataTable)(json)
        dlCustomers.DataBind()
    End If
End Sub
 
 

Screenshot

Populate DataList using API in ASP.Net using C# and VB.Net
 
 

Demo

View Demo
 
 

Downloads

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