Javascript injection - WPF CefSharp 57.0.0

[Michael Muehr]

Hi all,

I have a simple WebPage (like: http://www.bbzsl.eu/bbzse/Vertretungsplaene/intern/klassemorgen/subst_001.htm ) and I want to inject some JavaScript code to manipulate the DOM. I tried to execute a simple alert, but either I get an error "Unable to execute javascript at this time.." or the script is not executed at all. Where can I put the ExecuteScriptAsync function to inject my JavaScript ?

private void InitWebControl()

 {

 WebControl.BrowserSettings = new BrowserSettings

 {

 ApplicationCache = CefState.Disabled,

 };

 

 //_webControl.LoadError += _webControl_LoadError;

 //_webControl.ConsoleMessage += _webControl_ConsoleMessage;

 //_webControl.FrameLoadStart += _webControl_FrameLoadStart;

 WebControl.FrameLoadStart += (sender, args) =>

 {

 if (WebControl.CanExecuteJavascriptInMainFrame)

 {

 WebControl.ExecuteScriptAsync(

 "var node = document.createElement('style'); node.innerHTML = 'html, body, iframe {overflow:hidden;}'; document.body.appendChild(node);");

 }

 };

 WebControl.IsBrowserInitializedChanged += (sender, args) =>

 {

 };

 WebControl.LoadingStateChanged += (sender, args) =>

 {

 if (WebControl.CanExecuteJavascriptInMainFrame)

 {

 WebControl.ExecuteScriptAsync("alert('All Resources Have Loaded');");

 }

 //Wait for the Page to finish loading

 if (args.IsLoading == false)

 {

 //error

 WebControl.ExecuteScriptAsync("alert('All Resources Have Loaded');");

 }

 };

 

 

WebControl.FrameLoadEnd += (sender, args) =>

 {

 //not fired

 if (WebControl.CanExecuteJavascriptInMainFrame)

 {

 WebControl.ExecuteScriptAsync("alert('All Resources Have Loaded');");

 }

 WebControl.ExecuteScriptAsync("alert('All Resources Have Loaded');");

 };