AuthnRequest Class

public class AuthnRequest : RequestAbstractType

Public Class AuthnRequest
   Inherits RequestAbstractType

public ref class AuthnRequest : public RequestAbstractType

Shows how to create an AuthnRequest request and send it over HTTP POST or HTTP Redirect.

using System.Security.Cryptography.X509Certificates;
using System.Web;
using ComponentPro.Saml2;

...

// Create a new instance of the AuthnRequest class.
AuthnRequest request = new AuthnRequest();
request.IsPassive = false;
// Set Protocol Binding.
request.ProtocolBinding = SamlBindingUri.HttpPost;
// Set the target provider's Assertion Consumer Service Url.
request.AssertionConsumerServiceUrl = "your url";

// Set Issuer
request.Issuer = new Issuer();
request.Issuer.NameIdentifier = "your name identifier";

request.NameIdPolicy = new NameIdPolicy();
request.NameIdPolicy.SpNameQualifier = "moodle.sp.myname";
request.NameIdPolicy.AllowCreate = true;
request.NameIdPolicy.Format = SamlNameIdentifierFormat.Persistent;

request.RequestedAuthnContext = new RequestedAuthnContext();
request.RequestedAuthnContext.Comparison = SamlAuthenticationContextComparison.Exact;
request.RequestedAuthnContext.AuthenticationContexts.Add(new AuthnContextClassRef(SamlAuthenticationContext.PasswordProtectedTransport));

// Send the request over HTTP POST
request.SendHttpPost(Response, "http://mybaseurl", "my_relay_state");

// Or you can send it over HTTP Redirect 
// X509Certificate2 certificate = new X509Certificate2("PKey.pfx", "password");
// request.Redirect(Response, "http://mybaseurl", "my_relay_state", certificate.PrivateKey);

Imports System.Security.Cryptography.X509Certificates
Imports ComponentPro.Saml2

...

' Create a new instance of the AuthnRequest class. 
Dim request As New AuthnRequest()
request.IsPassive = False 
' Set Protocol Binding.
request.ProtocolBinding = SamlBindingUri.HttpPost
' Set the target provider's Assertion Consumer Service Url.
request.AssertionConsumerServiceUrl = "your url" 
 
' Set Issuer
request.Issuer = New Issuer()
request.Issuer.NameIdentifier = "your name identifier"

request.NameIdPolicy = New NameIdPolicy()
request.NameIdPolicy.SpNameQualifier = "moodle.sp.myname"
request.NameIdPolicy.AllowCreate = True
request.NameIdPolicy.Format = SamlNameIdentifierFormat.Persistent

request.RequestedAuthnContext = New RequestedAuthnContext()
request.RequestedAuthnContext.Comparison = SamlAuthenticationContextComparison.Exact
request.RequestedAuthnContext.AuthenticationContexts.Add(New AuthnContextClassRef(SamlAuthenticationContext.PasswordProtectedTransport))

' Send the request over HTTP POST
request.SendHttpPost(Response, "http://mybaseurl", "my_relay_state")

' Or you can send it over HTTP Redirect 
' X509Certificate2 certificate = new X509Certificate2("PKey.pfx", "password");
' request.Redirect(Response, "http://mybaseurl", "my_relay_state", certificate.PrivateKey);

Reference