Called when the browser begins loading a frame. The Frame value will never be empty Check the IsMain method to see if this frame is the main frame. Multiple frames may be loading at the same time. Sub-frames may start or continue loading after the main frame load has ended. This method may not be called for a particular frame if the load request for that frame fails. For notification of overall browser load status use OnLoadingStateChange(IWebBrowser, LoadingStateChangedEventArgs) instead. This method will be called on the CEF UI thread. Blocking this thread will likely cause your UI to become unresponsive and/or hang.

void OnFrameLoadStart(
	IWebBrowser browserControl,
	FrameLoadStartEventArgs frameLoadStartArgs
)

void OnFrameLoadStart(
	IWebBrowser^ browserControl, 
	FrameLoadStartEventArgs^ frameLoadStartArgs
)