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Winform App - Webpage Interaction

Windows Form Application - Manipulating Input Elements in WinForm WebBrowser

Although I am familiar with the HttpWebResponse / HttpWebRequest for entering the site, I tried it now using the mshtml library and found some strange behavior, and I would like to know if someone else can help me here ..

I have an HTML login page with a java database with Username field, Password field and Button .

The logic is very simple, I have a built-in winform application with a built-in web browser. In the Document_Completed event, I use the following code to enter my settings and click a button.

 private void webBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e) { if (webBrowser.Url.ToString() == @"MyWebPage/signin") { HTMLDocument hdc = new HTMLDocumentClass(); hdc = (HTMLDocument)webBrowser.Document.DomDocument; IHTMLElement elb = hdc.getElementById("login_button"); IHTMLInputElement elu = (IHTMLInputElement)hdc.getElementById("username"); IHTMLInputElement elp = (IHTMLInputElement)hdc.getElementById("password"); try { elu.value = "MyID"; elp.value = "MyPwd"; elb.click(); } catch { } } }

Besides the fact that this code is very fast and without error handling, it should do the trick, and this happens partially.

There are two scenarios:

  • I run the tool, it loads a web page.

    • The tool fills in the UserID field and Password field correctly
    • Tool cannot press button

  • I press the button manually, I logged in, I log out, I returned to the login page

    • I immediately logged in again, the tool enters information
    • The tool immediately presses the button.

Is there anyone who could explain to me why this is happening and how I could get around this with the current setting (hence not using HttpWebRequest ). I don’t see the difference between loading the page at startup or redirecting after logging out, but apparently there is a difference there, or I'm doing something wrong.

Any feedback on this is greatly appreciated.

Thanks Kevin

EDIT:

I added a Button to my Windows Form, which is based on the same base code as below, to click a button on a web page, this works fine.

I clicked this button in the webBrowser_Completed event, but it does not work. For some reason, everything I add to the webBrowser_DocumentCompleted event webBrowser_DocumentCompleted not allow the click event to be webBrowser_DocumentCompleted for a button in a WebBrowser . As soon as this whole event ends, if I then try to fire it, it will work, but I would like to automate this. Any tips?

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2 answers

It may be a long shot, not the most elegant workaround, but how about a minor statement executing a second in your DocumentCompleted event, which then fires a button that you click on a separate thread from. It can be just automated. Since this will work from a different thread, keep in mind that you may need to invoke certain controls so that this might be another drawback of this workaround.

If this does not work, then, as Regfor previously suggested, Watin.org can help you.

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how about this:

 HtmlElement button = webBrowser.HtmlDocument.GetElementById("login_button"); button.InvokeMember("click");

It works in my program.

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Source: https://habr.com/ru/post/915485/

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