Call a C# function by clicking on a button in WebBrowser Control

Question

I am working on a project. I am using CEFSharp (Chromium Embedded Framework) in C# Windows Forms. I also have a HTML web page in my solution. I am navigating my WebBrowser Control to that HTML page. The HTML page contains a button. How can I call a C# Function when user clicks that button on that HTML page?

Answer 1

I took this code from the CEFSharp wiki ; hopefully this will help you.

public class BoundObject
{
   public void OnFrameLoadEnd (object sender, FrameLoadEndEventArgs e)
    {
        if(e.Frame.IsMain)
        {
            browser.ExecuteScriptAsync(@"
             document.body.onmouseup = function()
             {
               bound.onSelected(window.getSelection().toString());
             }
            ");
        }
    }
    public void OnSelected(string selected)
    {
        MessageBox.Show("The user selected some text [" + selected + "]");
    }
}

After initializing the CEF object, register the JavaScript object:

var obj = new BoundObject();
browser.RegisterJsObject("bound", obj);
browser.FrameLoadEnd += obj.OnFrameLoadEnd;

Answer 2

First of all create this class;

    public class BoundObject
    {

        public delegate void ItemClickedEventHandler(object sender, HtmlItemClickedEventArgs e);
        public event ItemClickedEventHandler HtmlItemClicked;

        public delegate void ItemResponseEventHandler(object sender, GetResponseEventArgs e);
        public event ItemResponseEventHandler ItemResponse;


        private ChromiumWebBrowser browser;

        public BoundObject(ChromiumWebBrowser br) { browser = br; }


        public void OnFrameLoadEnd(object sender, FrameLoadEndEventArgs e)
        {
            if (e.Frame.IsMain)
            {
                ////browser.ExecuteScriptAsync(@"
                ////    document.body.onmouseup = function()
                ////    {
                ////        bound.onSelected(window.getSelection().toString());
                ////    }
                ////");

                browser.EvaluateScriptAsync(@"window.onclick = function(e) { e.preventDefault(); bound.onClicked(e.target.outerHTML); }");

            }
        }

        public void OnSelected(string selected)
        {
            MessageBox.Show("The user selected some text [" + selected + "]");
        }

        public void OnClicked(string id)
        {
            if (HtmlItemClicked != null)
            {
                HtmlItemClicked(this, new HtmlItemClickedEventArgs() { Id = id });
            }
        }

        public void OnResponse(string projectId, string automationTaskId, string responseText)
        {
            if (ItemResponse != null)
            {
                ItemResponse(this, new GetResponseEventArgs() { AutomationTaskId = automationTaskId, ProjectId = projectId, ResponseText = responseText });
            }
        }
    }

    public class HtmlItemClickedEventArgs : EventArgs
    {
        public string Id { get; set; }
    }

    public class GetResponseEventArgs : EventArgs
    {
        public string ProjectId { get; set; }
        public string AutomationTaskId { get; set; }
        public string ResponseText { get; set; }
    }

then;

       public frmProjectDetail()
    {
        InitializeComponent();
        browser = new ChromiumWebBrowser("http://www.google.com.tr")
        {
            Dock = DockStyle.Fill,
        };
        //browser.RegisterJsObject("bound", bound);
        splitContainerControl2.Panel1.Controls.Add(browser);

        browser.LoadingStateChanged += OnLoadingStateChanged;
        browser.ConsoleMessage += OnBrowserConsoleMessage;
        browser.StatusMessage += OnBrowserStatusMessage;
        browser.TitleChanged += OnBrowserTitleChanged;
        browser.AddressChanged += OnBrowserAddressChanged;
        browser.MouseClick += Browser_MouseClick;

        var obj = new BoundObject(browser);
        obj.HtmlItemClicked += Obj_HtmlItemClicked;
        obj.ItemResponse += Obj_ItemResponse;
        browser.RegisterJsObject("bound", obj);
        browser.FrameLoadEnd += obj.OnFrameLoadEnd;
        browser.DialogHandler = new SilentDialogHandler();
    }



    private void Obj_HtmlItemClicked(object sender, HtmlItemClickedEventArgs e)
    {
        this.InvokeOnUiThreadIfRequired(() => setMemoText("Tıklanan Element: " + e.Id));
    }

Also dont forget to implement other browser events declared in code. When user cliks any html element private void Obj_HtmlItemClicked triggers