Question about browser not being loaded.

[krubin723]

Hi,

I am having much difficulty now loading the browser.

• We have a WPF application. It was on version 75. I have been testing versions 84 and 89. The PCs are both on Windows 10 Personal and Enterprise.

• This reason for this is referenced in my earlier post today:L:ocal PDF files not displayed. Question about versions. #4633

• The error is: CefSharp.Wpf.ChromiumWebBrowser getbrowser method throws 'The ChromiumWebBrowser instance creates the underlying Chromium Embedded Framework (CEF) browser instance in an async fashion. The undelying CefBrowser instance is not yet initialized.

• I initialize CefSettings shown below.
  -var cefSettings = new CefSharp.Wpf.CefSettings
  {
  // RemoteDebuggingPort = 18888
  LogSeverity = LogSeverity.Verbose,
  //CachePath = SystemService.CefCacheDir,
  //LogFile = SystemService.CefSharpLogFile
  };
  CefSharp.Cef.Initialize(cefSettings);
  -The program throws an exception on the bolded line.: Also even if I set a breakpoint and wait for a minute, the browser never loads."IsLoaded" property is false. The "Isloading" property is also false.
  public static void InvokeScript(ChromiumWebBrowser browser, string basecode, params string[] arguments)
  {
  var instance = browser.GetBrowser();
  ...
  -When using version 87, the stack trace is shown below
  Unhandled Exception: System.Exception: The ChromiumWebBrowser instance creates the underlying Chromium Embedded Framework (CEF) browser instance in an async fashion. The undelying CefBrowser instance is not yet initialized. Use the IsBrowserInitializedChanged event and check the IsBrowserInitialized property to determine when the browser has been initialized. I realise this is asynchronous. "IsInitialized" is true.
  at CefSharp.Wpf.ChromiumWebBrowser.ThrowExceptionIfBrowserNotInitialized() in C:\projects\cefsharp\CefSharp\Internals\Partial\ChromiumWebBrowser.Partial.cs:line 329
  at CefSharp.Wpf.ChromiumWebBrowser.GetBrowser() in C:\projects\cefsharp\CefSharp.Wpf\ChromiumWebBrowser.cs:line 2630
  at POSBrowserInterface.CefInterface.InvokeScript(ChromiumWebBrowser browser, String basecode, String[] arguments) in C:\bms-04052023\bms-2\BMS_Client\POSBrowserInterface\CefInterface.cs:line 12
  at BMSClient.POSClient.MainWindow.wnd_SizeChanged(Object sender, SizeChangedEventArgs e) in C:\bms-04052023\bms-2\BMS_Client\POSClient\MainWindow.xaml.cs:line 1396
  at System.Windows.SizeChangedEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
  at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
  at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
  at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
  at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
  at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
  at System.Windows.FrameworkElement.OnRenderSizeChanged(SizeChangedInfo sizeInfo)
  at System.Windows.ContextLayoutManager.fireSizeChangedEvents()
  at System.Windows.ContextLayoutManager.UpdateLayout()
  at System.Windows.UIElement.UpdateLayout()
  at System.Windows.Interop.HwndSource.SetLayoutSize()
  at System.Windows.Interop.HwndSource.set_RootVisualInternal(Visual value)
  at System.Windows.Interop.HwndSource.set_RootVisual(Visual value)
  at System.Windows.Window.SetRootVisual()
  at System.Windows.Window.SetRootVisualAndUpdateSTC()
  at System.Windows.Window.SetupInitialState(Double requestedTop, Double requestedLeft, Double requestedWidth, Double requestedHeight)
  at System.Windows.Window.CreateSourceWindow(Boolean duringShow)
  at System.Windows.Window.CreateSourceWindowDuringShow()
  at System.Windows.Window.SafeCreateWindowDuringShow()
  at System.Windows.Window.ShowHelper(Object booleanBox)
  at System.Windows.Window.Show()
  at System.Windows.Application.<>c.b__105_0(Object obj)
  at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
  at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
  at System.Windows.Threading.DispatcherOperation.InvokeImpl()
  at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
  at MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(Object obj)
  at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
  at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
  at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
  at MS.Internal.CulturePreservingExecutionContext.Run(CulturePreservingExecutionContext executionContext, ContextCallback callback, Object state)
  at System.Windows.Threading.DispatcherOperation.Invoke()
  at System.Windows.Threading.Dispatcher.ProcessQueue()
  at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
  at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
  at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
  at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
  at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
  at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
  at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
  at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
  at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
  at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
  at System.Windows.Application.RunDispatcher(Object ignore)
  at System.Windows.Application.RunInternal(Window window)
  at System.Windows.Application.Run(Window window)
  at BMSClient.POSClient.App.<>c.

  b__2_0() in C:\bms-04052023\bms-2\BMS_Client\POSClient\App.xaml.cs:line 43
  at BloomNetClient.Common.Helpers.SingleStartup(Guid applicationIdentifier, String applicationName, ILog logger, Action startUp) in C:\bms-04052023\bms-2\BloomLink_Client\BloomNetClient.Common\Helpers.cs:line 130
  at BMSClient.POSClient.App.Main() in C:\bms-04052023\bms-2\BMS_Client\POSClient\App.xaml.cs:line 35
  The program '[28060] BMSClient.POSClient.exe' has exited with code 0 (0x0).

Please assist.
Thank you,
Ken

[krubin723]

The versions tested were not 84 and 89, but 87 and 89

[amaitland]

• 'The ChromiumWebBrowser instance creates the underlying Chromium Embedded Framework (CEF) browser instance in an async fashion. The undelying CefBrowser instance is not yet initialized.

You are trying to execute your javascript before the browser has finished initializing, it hasn't even started loading the web page yet.

See https://github.com/cefsharp/CefSharp/wiki/General-Usage#when-can-i-start-executing-javascript for some guidance.

• I have been testing versions 84 and 89.

Not supported. M119 is the current supported version.

The versions tested were not 84 and 89, but 87 and 89

[krubin723]

Hi Alex.

We are in the process of preparing to go to version 119 of CefSharp. One of our Engineers is updating us to .Net 4.6.2 now.
However as a stopgap, I was asked to repair an issue on version 99.2.120. I hope you may tolerate a question about it?

I am using the RenderProcessMessageHandler.
The OnContextCreated function does do the callback on the main frame,
However there are other frames, which are not main and they attempt to run the ExecuteJavaScriptAsync function, before the OnContextCreated function is called.

I've tried to run timing loops for a few seconds to slow these non Main frames down, until I sent a receipt from the OnContextCreated function that it has been called back, but that does not work. It appears that the OnContextCreated would work on version 99.2.120.

I would ideally run Javascript on the frame in the OnContextCreated function, but it does not receive all of the frames.

I'm sure I'm not connecting all of the dots, could you please assist?

Thank you,
Ken

[krubin723]

I am getting this exception: "The ChromiumWebBrowser instance creates the underlying Chromium Embedded Framework (CEF) browser instance in an async fashion. The undelying CefBrowser instance is not yet initialized. Use the IsBrowserInitializedChanged event and check the IsBrowserInitialized property to determine when the browser has been initialized."}

[amaitland]

M114 is the last version to support .Net 4.5.2.

Try using FrameLoadStart and executing directly against the main frame (a frame reference will be part of the event args).

If you are still having problems after upgrading to the latest supported version (M120 at time of writing) then please provide an actual code example.