Post data parameters with url in Cefsharp chromiumwebbrowser

I am using a web interface within my c# windows form application using Cefsharp libraries.I can load my tab page with the browser using the following code

        Cef.EnableHighDPISupport();
        CefSettings settings = new CefSettings();         
        Cef.Initialize(settings);            
        chromeBrowser = new ChromiumWebBrowser("http://localhost/myproject/login.php"); 
        tab_web.Controls.Add(chromeBrowser);

But I am unable to post the login credential to the page (metod is POST) so that i can register the session and the user can direct access to his profile from the application. UPDATE

public partial class Form1 : Form
{
    public void InitializeChromium()
    {
        Cef.EnableHighDPISupport();
        CefSettings settings = new CefSettings();
        settings.RemoteDebuggingPort = 8088;
        Cef.Initialize(settings);
        ChromiumWebBrowser chromeBrowser = new ChromiumWebBrowser("http://localhost/test.php");
        chromeBrowser.RequestHandler = new CustomRequestHandler();
        tab_web.Controls.Add(chromeBrowser);
        chromeBrowser.Dock = DockStyle.Fill;    
    }
public Form1()
    {
        InitializeComponent();      
         InitializeChromium();
     }
    public  void load_browser()
    {
        ChromiumWebBrowser chromeBrowser = new ChromiumWebBrowser();
        byte[] request = Encoding.ASCII.GetBytes("data1=sssss&data2=sssss");
        PostTest.Navigate( chromeBrowser, "http://localhost/test.php", request, "application/x-www-form-urlencoded");
        tab_gis.Controls.Add(chromeBrowser);
    }
}
public class CustomRequestHandler : CefSharp.Handler.RequestHandler
{
    protected override IResourceRequestHandler GetResourceRequestHandler(IWebBrowser chromiumWebBrowser, IBrowser browser, IFrame frame, IRequest request, bool isNavigation, bool isDownload, string requestInitiator, ref bool disableDefaultHandling)
    {
        if (request.Url == "http://localhost/test.php")
        {
            return new CustomResourceRequestHandler();
        }
        return null;
    }
}
public class CustomResourceRequestHandler : CefSharp.Handler.ResourceRequestHandler
{
    protected override CefReturnValue OnBeforeResourceLoad(IWebBrowser chromiumWebBrowser, IBrowser browser, IFrame frame, IRequest request, IRequestCallback callback)
    {
        var postData = new PostData();
        MessageBox.Show("HHHH");
        postData.AddData("test=123&data2=456");
        request.Method = "POST";
        request.PostData = postData;
        return CefReturnValue.Continue;
    }
}

screenshot of the reply from the httpbin is as attached

Meanwhile the form data submission should be as follows

I changed the content type to multipart/form-data , text, xml, etc. nothing helped me.

Solution

Credit to Amaitland. He gives the necessary directions with examples through which I got the solution of this problem. I am posting the working code here for help to any other Cefsharp user.

    public class CustomRequestHandler : CefSharp.Handler.RequestHandler
{
    protected override IResourceRequestHandler GetResourceRequestHandler(IWebBrowser chromiumWebBrowser, IBrowser browser, IFrame frame, IRequest request, bool isNavigation, bool isDownload, string requestInitiator, ref bool disableDefaultHandling)
    {
        //Where possible only intercept specific Url's
        //Load http://httpbin.org/post in the browser and you'll
        //see the post data
        if (request.Url == "http://httpbin.org/post")
        {
            return new CustomResourceRequestHandler();
        }

        //Default behaviour, url will be loaded normally.
        return null;
    }
}

public class CustomResourceRequestHandler : CefSharp.Handler.ResourceRequestHandler
{
    protected override CefReturnValue OnBeforeResourceLoad(IWebBrowser chromiumWebBrowser, IBrowser browser, IFrame frame, IRequest request, IRequestCallback callback)
    {
                //Modify the request to add post data
        //Make sure to read https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST
        var postData = new PostData();

        postData.AddData("test=123&data=456");

        request.Method = "POST";
        request.PostData = postData;
        //Set the Content-Type header to whatever suites your requirement
        request.SetHeaderByName("Content-Type", "application/x-www-form-urlencoded", true);
        //Set additional Request headers as required.

        return CefReturnValue.Continue;
    }
}

//Load http://httpbin.org/post in the browser to see the post data
browser = new ChromiumWebBrowser("http://httpbin.org/post");
browser.RequestHandler = new CustomRequestHandler();

For more details, pl refer https://github.com/cefsharp/CefSharp/wiki/General-Usage#load-url-with-postdata