In this article I will explain with an example, how to use Antiforgery Token with submit in ASP.Net using C# and VB.Net.
 
 

Install Microsoft.AspNet.WebPages Nuget Package

First you need to install the Microsoft.AspNet.WebPages package from Nuget.
In order to install Microsoft.AspNet.WebPages package from Nuget, please refer my article Install Microsoft.AspNet.WebPages Nuget Package.
 
 

HTML Markup

The following HTML Markup consists of:
TextBox – For capturing Name.
DropDownList – For selecting Country to be submit.
Button – For submitting the Form.
The Button has been assigned with an OnClick event handler.
The Anti-Forgery Token has been added to the HTML using the GetHtml method of the AntiForgery class.
Note: The AntiForgeryToken function generates a HiddenField with the AntiForgery Token.
 
<%= System.Web.Helpers.AntiForgery.GetHtml()%>
<table>
    <tr>
        <td>Name:</td>
        <td><asp:TextBox ID="txtName" runat="server"></asp:TextBox></td>
    </tr>
    <tr>
        <td>Country:</td>
        <td>
            <asp:DropDownList ID="ddlCountries" runat="server">
                <asp:ListItem Text="Please select" Value=""></asp:ListItem>
                <asp:ListItem Text="United States" Value="United States"></asp:ListItem>
                <asp:ListItem Text="India" Value="India"></asp:ListItem>
                <asp:ListItem Text="France" Value="France"></asp:ListItem>
                <asp:ListItem Text="Russia" Value="Russia"></asp:ListItem>
            </asp:DropDownList>
        </td>
    </tr>
    <tr>
        <td></td>
        <td><asp:Button ID="btnSubmit" runat="server" Text="Submit" OnClick="OnSubmit" /></td>
    </tr>
</table>
 
 

Namespaces

You will need to import the following namespace.
C#
using System.Web.Helpers;
 
VB.Net
Imports System.Web.Helpers
 
 

Assigning AntiForgery in Page Load

Inside the Page_Load event handler, Validate method of AntiForgery class is called to prevent cross-site request forgery attacks inside the IsPostBack condition.
Note: A cross-site request forgery is an attack is done by sending harmful script element, malicious command, or code from the user’s browser.
 
C#
protected void Page_Load(object sender, EventArgs EventArgs  e)
{
    if (this.IsPostBack)
    {
        // Throws Exception if AntiForgery check fails.
        AntiForgery.Validate();
    }
}
 
VB.Net
Protected Sub  Page_Load(sender As Object, e As EventArgs)
    If Me.IsPostBack Then
        ' Throws Exception if AntiForgery check fails.
        AntiForgery.Validate()
    End If
End Sub
 
 

Submitting the Form

When the Button is clicked, value of the Name and Country are fetched from their respective controls and displayed using JavaScript Alert Message Box using RegisterStartupScript method of ClientScript class.
C#
protected void OnSubmit(object sender, EventArgs e)
{
    string name = txtName.Text;
    string country = ddlCountries.SelectedItem.Text;
    ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('Customer inserted successfully.');", true); 
}
 
VB.Net
Protected Sub OnSubmit(sender As Object, e As EventArgs)
    Dim name As String = txtName.Text
    Dim country As String = ddlCountries.SelectedItem.Text
    ClientScript.RegisterStartupScript(Me.GetType(), "alert", "alert('Customer inserted successfully.');", True)
End Sub
 
 

Screenshot

Using AntiForgery Token with Submit in ASP.Net
 
 

Downloads

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