Element "webBrowser". How to wait for the page to load?

Question

Document structure
"Form0" - Form
- - "panel2" - Panel
- - - "Frm5UC" - Custom item
- - - - "webBrowser1" - Browser

Application logic:
- go to the page in "webBrowser1";
- enter login;
- enter the password;
- click the "Login" button.

If I execute the logic through the code (this is the "Method_0 ()" method), the form does not have time to load in the "Authorization ()" method. I get "webBrowser1.Document = null", error "Object link does not indicate an object instance."

If I do everything through the interface, then everything works.

How to make the logic run programmatically?

private void Frm5UC_Load(object sender, EventArgs e)
        {
            webBrowser1.Visible = true;

            // *** TESTS ***
            Method_0();
        }



        #region *** TESTS ***
        public void Method_0()
        {
            Method_1();
            // Method_2();
        }

        public void  Method_1()
        {
            textBox2.Text = "_domain_com";
            textBox1.Text = @"domain_com/login/";

            button1.PerformClick();
        }

        public void Method_2() // Авторизация
        {
            Authorization();
        }
        #endregion *** TESTS ***


        private void button1_Click(object sender, EventArgs e)
        {
            webBrowser1.Navigate(textBox1.Text);            
        }       

        private void button2_Click(object sender, EventArgs e)
        {
            Authorization();
        }       

        public void Authorization() // Авторизация
        {            
                foreach (HtmlElement he in webBrowser1.Document.GetElementsByTagName("input"))
                {
                    if (he.GetAttribute("name") == "login[login]")
                    {
                        he.SetAttribute("value", "login798");
                    }
                }

            // Code "enter password"
            // Code "Press the button"
        }

Update.
I try to use the event "DocumentCompleted".
Added the variable "bool statusAuthorization;".

As a result: - a page with fields for entering login / password opens; and nothing else happens. The code does not enter the login / password.

I try to do debugging.
Steps through the entire code.
No errors. Everything works, but the form with the browser does not open.

If I log in through the interface, then everything works.

bool statusAuthorization;

    private void Frm5UC_Load(object sender, EventArgs e)
    {
            webBrowser1.Visible = true;

            statusAuthorization = true; // !!! CHANGES

            // *** ТЕСТ ***
            Method_0();
    }

        private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
    {
        if (webBrowser1.ReadyState != WebBrowserReadyState.Complete) return;

        if (statusAuthorization == true)
        {
            Authorization();
        }
    }

        #region *** TESTS ***
        public void Method_0()
        {
            Method_1();
            // Method_2();
        }

        public void  Method_1()
        {
            textBox2.Text = "_domain_com";
            textBox1.Text = @"domain_com/login/";

            button1.PerformClick();
        }

        public void Method_2() // Авторизация
        {
            Authorization();
        }
        #endregion *** TESTS ***


        private void button1_Click(object sender, EventArgs e)
        {
            webBrowser1.Navigate(textBox1.Text);            
        }       

        private void button2_Click(object sender, EventArgs e)
        {
            Authorization();
        }       

        public void Authorization() // Авторизация
        {            
                foreach (HtmlElement he in webBrowser1.Document.GetElementsByTagName("input"))
                {
                    if (he.GetAttribute("name") == "login[login]")
                    {
                        he.SetAttribute("value", "login798");
                    }
                }

            // Code "enter password"
            // Code "Press the button"

            statusAuthorization = false; // !!! CHANGES
        }

Update
Result: the form loads again and again.

private void Frm5UC_Load(object sender, EventArgs e)
        {
            string s = "stop";
            webBrowser1.Visible = true;    

            webBrowser1.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(DocumentCompletedHandler);

            // *** ТЕСТ ***
              Method_1();
        }

     private void DocumentCompletedHandler(object sender, WebBrowserDocumentCompletedEventArgs e)
            {
                //Done!
                Authorization();
            }

You should probably use the WebBrowser's [DocumentCompleted](https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.webbrowser.documentcompleted?view=netframework-4.7.2) event. — LarsTech, Dec 23 '18 at 19:05
@LarsTech I tried to use it. Does not work. Could you tell me how to use it correctly? `private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)` — user9776818, Dec 23 '18 at 19:13
@Jimi I don't understand how to organize the code. What method to place there? `Test2 ();`? — user9776818, Dec 23 '18 at 19:28
You probably want [something like this](https://stackoverflow.com/questions/53213782/how-to-get-real-video-url-video-tag?answertab=active#tab-top). — Jimi, Dec 23 '18 at 19:30
@Jimi I try to do this, but the code does not work exactly as I need `private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e) { if (webBrowser1.ReadyState != WebBrowserReadyState.Complete) return; Authorization(); }` — user9776818, Dec 23 '18 at 19:36
Wouldn't there be two document completes? First time loads the login page, and a second time for when a user successfully logs in? You would have to know which page you are looking at. — LarsTech, Dec 23 '18 at 19:41
@LarsTech I ask you to excuse me, but still I do not understand how to arrange this event correctly. All my attempts do not lead to the result. Could you help or give a hint how to do this? — user9776818, Dec 23 '18 at 20:11
We don't see all your attempts. The DocumentCompleted event is pretty simple. When the document is finished loading, the event will run. It's not clear what is null in your code when that event runs. — LarsTech, Dec 23 '18 at 20:14

I_Al-thamary · Answer 1 · 2018-12-24T08:01:06.323

0

Try this:

bool statusAuthorization;

private void Frm5UC_Load(object sender, EventArgs e)
{
        webBrowser1.Visible = true;

        statusAuthorization = true; // !!! CHANGES

        // *** ТЕСТ ***

}

    private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
    if (webBrowser1.ReadyState != WebBrowserReadyState.Complete) return;

    if (statusAuthorization == true && webBrowser1.Document != null)
    { Method_1();
        Authorization();
    }
}

    #region *** TESTS ***


    public void  Method_1()
    {
        textBox2.Text = "_domain_com";
        textBox1.Text = @"domain_com/login/";


    }






    private void button1_Click(object sender, EventArgs e)
    {Method_1();
        Authorization();
    }       

    public void Authorization() // Авторизация
    {            
            foreach (HtmlElement he in webBrowser1.Document.GetElementsByTagName("input"))
            {
                if (he.GetAttribute("name") == "login[login]")
                {
                    he.SetAttribute("value", "login798");
                }
            }

        // Code "enter password"
        // Code "Press the button"

        statusAuthorization = false; // !!! CHANGES
    }

edited Dec 24 '18 at 08:01

answered Dec 23 '18 at 22:32

I_Al-thamary

3,385
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Sorry, I was wrong in the question. That's exactly what I did. Do you propose to do so? `public void Method_0 () { Method_1 (); } ` If yes, then I did. – user9776818 Dec 24 '18 at 06:47
@user9776818 yes and also you have two functions `button1_Click`. – I_Al-thamary Dec 24 '18 at 06:50
`you have two functions button1_Click` - сorrected. Sorry, once again I will note that your answer duplicates my update and does not lead to a positive result. I would appreciate if you advise something else. – user9776818 Dec 24 '18 at 06:55
Did you also remove `button1.PerformClick();` – I_Al-thamary Dec 24 '18 at 06:57
if it is not working check the error and do `if (webBrowser1.Document != null && webBrowser1.Document.Body != null) ` – I_Al-thamary Dec 24 '18 at 07:01
Did I understand you correctly? `private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e) { if (webBrowser1.Document != null && webBrowser1.Document.Body != null) { if (statusAuthorization == true) { Authorization(); } }` – user9776818 Dec 24 '18 at 07:21
As a result: - a page with fields for entering login / password opens; and nothing else happens. The code does not enter the login / password. I try to do debugging. Steps through the entire code. No errors. Everything works, but the form with the browser does not open. – user9776818 Dec 24 '18 at 07:21
See this:https://social.msdn.microsoft.com/Forums/windows/en-US/76b0feb2-6da6-468e-8956-92be1d7ac176/webbrowser-readystate-not-working?forum=winforms – I_Al-thamary Dec 24 '18 at 07:29
Try to remove `Method_0();` – I_Al-thamary Dec 24 '18 at 07:35
Updated question – user9776818 Dec 24 '18 at 07:49
Did you also remove from ` Method_1 ();` `button1.PerformClick();` – I_Al-thamary Dec 24 '18 at 07:52
I'm sorry, I did not understand. You ask a question or suggest removing `button1.PerformClick ();` – user9776818 Dec 24 '18 at 07:56
Try to remove it. – I_Al-thamary Dec 24 '18 at 07:56
Did I understand you correctly? `public void Method_1() { textBox2.Text = "_domain_com"; textBox1.Text = @"domain_com/login/"; webBrowser1.Navigate(textBox1.Text); // button1.PerformClick(); }` – user9776818 Dec 24 '18 at 08:04
I do not see in your code a transition to a page for entering a login and password. – user9776818 Dec 24 '18 at 08:10
Or do I not understand something? – user9776818 Dec 24 '18 at 08:11
@ There is no code for the password you have to add it `// Code "enter password" // Code "Press the button"` – I_Al-thamary Dec 24 '18 at 08:13
Your problem was about `webBrowser1.Document = null, error` – I_Al-thamary Dec 24 '18 at 08:14

Element "webBrowser". How to wait for the page to load?

1 Answers1