Uncheck a checkbox in webpage through WebBrowser control

Question

Is there a way to uncheck/check a checkbox within a webpage that is loaded within a webbrowser control? Thank you.

Update: (This is what I originally tried with no luck)

HtmlDocument rememberme = this.webBrowser1.Document;
rememberme.GetElementById("remBox").SetAttribute("checked", "false");

Solution 1

You can use:

webBrowser.Document.InvokeScript

see:

InvokeScript

This way you can call JS function that will do what you want to the page.

Another way is to use mshtml API, like this: ( ( HTMLInputElement )this.webBrowser1.Document.GetElementById( "test" ).DomElement ).@checked = false;

Solution 2

You can use the InvokeMember Method of a HTML Element to invoke a DOM Event. In our case "click". If you have a WebBrowser Control than all you have to do is find the element and Invoke the Method.

For Each ele As HtmlElement In Me.WebBrowser1.Document.All
        If ele.Name = "accept" Then
            ele.InvokeMember("click")
        End If
Next

In my example 'accept' was the name of the checkbox element. You can use the SetAttribute() for some other controls but the best way to emulate a click is to find what the checkbox state is by using GetAttribute() and click if the checkbox is set to false. Hope it helps.

Comments

[RegisteredUser]

What does that have to do with the webbrowser control?

[Sheng Jiang 蒋晟]

It would be more complicated if you skip .Net's wrapper classes and call IE API directly.

[user]

What would be a proper way to use JavaScript to uncheck a single checkbox?

[RegisteredUser]

My point is that once you've got the document in the webbrowser control you can manipulate the dom objects directly, without resorting to javascript.

[Majkel]

It depends - if you know checkbox's ID, then just use document.getElementById( 'yourid' ).checked = false; But if it is dynamic (like in ASP.NET in control) than you would have to use another way - locate it by class name, traverse DOM tree or something.

[Majkel]

It should be input.@checked = false;. And using JS you don't have to reference mshtml and you can do this in one line - this.webBrowser1.Document.InvokeScript( "uncheck" );.

[Majkel]

Well, one line in C# + one in JS.

[RegisteredUser]

Well I could condense it down to one line of C# if I really wanted to. ;) I suspect actually adding the script to the page and using it would end up being more.

[Majkel]

Solution with mshtml in my answer actually is one line ;) And JS approach to be one line would require access to the page source - otherwise it would be necessary to use mshtml API to insert your script.