"Cef can only be initialized once" when registered js object - chromium-embedded

Question

I'm using CefSharp.WinForm 51.0.0.
When I added code registring js object after Cef.Initialize(settings),
The exception occurs at runtime on Cef.Initialize(settings).
System.Exception was unhandled
HResult=-2146233088
Message=Cef can only be initialized once. Use Cef.IsInitialized to guard against this exception.
Source=CefSharp.Core
StackTrace:
위치: CefSharp.Cef.Initialize(CefSettings cefSettings, Boolean shutdownOnProcessExit, Boolean performDependencyCheck)
위치: CefSharp.Cef.Initialize(CefSettings cefSettings)
위치: PcAppCef_WinForm.AppForm.InitializeChromium() 파일 d:\VisualStuidoRepo\StocktalkPC\PcAppCef_WinForm\AppForm.cs:줄 82
위치: PcAppCef_WinForm.AppForm..ctor() 파일 d:\VisualStuidoRepo\StocktalkPC\PcAppCef_WinForm\AppForm.cs:줄 53
위치: PcAppCef_WinForm.AppViewport..ctor() 파일 d:\VisualStuidoRepo\StocktalkPC\PcAppCef_WinForm\AppViewport.cs:줄 15
위치: PcAppCef_WinForm.AppForm.InitializeChromium() 파일 d:\VisualStuidoRepo\StocktalkPC\PcAppCef_WinForm\AppForm.cs:줄 90
위치: PcAppCef_WinForm.AppForm..ctor() 파일 d:\VisualStuidoRepo\StocktalkPC\PcAppCef_WinForm\AppForm.cs:줄 53
위치: PcAppCef_WinForm.Program.Main() 파일 d:\VisualStuidoRepo\StocktalkPC\PcAppCef_WinForm\Program.cs:줄 19
However, I just called .RegisterJsObject() method after Cef.Initialize
and when I removed(or commented) my code chromeBrowser.RegisterJsObject then works very well.
I don't understand why error occurs at Initialize method not RegisterJsObject.
This is my code.
public void InitializeChromium()
{
System.Console.WriteLine("*** Initializing Chromium");
CefSettings settings = new CefSettings();
Cef.Initialize(settings);
chromeBrowser = new ChromiumWebBrowser(WebAppUrl);
chromeBrowser.DownloadHandler = new FileDownloadHandler();
chromeBrowser.MenuHandler = new ContextMenuHandler();
//chromeBrowser.RequestHandler = new AppRequestHandler();
// I want to a add js object but when I add this code, an error occurs on Cef.Initialize() as the blackquote above.
chromeBrowser.RegisterJsObject("AppViewport", new AppViewport());
this.Controls.Add(chromeBrowser);
chromeBrowser.Dock = DockStyle.Fill;
}

Answer 1

Can you please check initial before. I think it help you:
public void InitializeChromium()
{
System.Console.WriteLine("*** Initializing Chromium");
if (!Cef.IsInitialized) // Check before init
{
CefSettings settings = new CefSettings();
Cef.Initialize(settings);
}
chromeBrowser = new ChromiumWebBrowser(WebAppUrl);
chromeBrowser.DownloadHandler = new FileDownloadHandler();
chromeBrowser.MenuHandler = new ContextMenuHandler();
//chromeBrowser.RequestHandler = new AppRequestHandler();
// I want to a add js object but when I add this code, an error occurs on Cef.Initialize() as the blackquote above.
chromeBrowser.RegisterJsObject("AppViewport", new AppViewport());
this.Controls.Add(chromeBrowser);
chromeBrowser.Dock = DockStyle.Fill;
}