/// <summary>
/// Refreshes the current page.
/// </summary>
/// <param name="noCache">Whether to refresh without cache validation by sending "Pragma:no-cache" header to the server.</param>
public void Refresh(bool noCache)
{
VerifyAccess();
// Out of the three options of RefreshConstants, we only expose two: REFRESH_NORMAL and REFRESH_COMPLETELY,
// because the thrid option, RefreshConstants.REFRESH_IFEXPIRED, is not implemented by IWebBrowser2.Refresh.
// And those two options cover the common scenarios.
//
// enum RefreshConstants{
// REFRESH_NORMAL = 0,
// REFRESH_IFEXPIRED = 1 /* Not supported by IWebBrowser2*/,
// REFRESH_COMPLETELY = 3
// }
int refreshOption = noCache ? 3 : 0;
object refreshOptionObject = (object)refreshOption;
AxIWebBrowser2.Refresh2(ref refreshOptionObject);
}
private void DoNavigate(Uri source, ref object targetFrameName, ref object postData, ref object headers, bool ignoreEscaping = false)
{
VerifyAccess();
// TFS - Calling Navigate and NavigateToStream subsequently causes internal state
// of the WebBrowser control to become invalid. By cancelling outstanding navigations in the
// browser, we make sure not to get a NavigationCompleted2 event for the original request while
// we've already overwritten internal state (more specifically the NavigatingToAboutBlank and
// DocumentStream properties), therefore avoiding the Invariant.Assert over there to fail.
// Notice we're passing showCancelPage = false as the input parameter. This keeps the browser
// from navigating to res://ieframe.dll/navcancl.htm because of the cancellation (which would
// by itself cause navigation events to occur). See inetcore/ieframe/shdocvw/shvocx.cpp.
NativeMethods.IOleCommandTarget cmdTarget = (NativeMethods.IOleCommandTarget)AxIWebBrowser2;
object showCancelPage = false;
cmdTarget.Exec(
null /* default command group */,
(int)UnsafeNativeMethods.OLECMDID.OLECMDID_STOP,
(int)UnsafeNativeMethods.OLECMDEXECOPT.OLECMDEXECOPT_DODEFAULT,
new object[] { showCancelPage }, /* don't navigate to res://ieframe.dll/navcancl.htm */
0
);
// TFS - Launching a navigation from the Navigating event handler causes reentrancy.
// For more info, see WebBrowser.LastNavigation. Here we generate a new navigation identifier which
// is used to detect reentrant calls during handling of the Navigating event.
LastNavigation = Guid.NewGuid();
// When source set to null or navigating to stream/string, we navigate to "about:blank" internally.
if (source == null)
{
NavigatingToAboutBlank = true;
source = new Uri(AboutBlankUriString);
}
else
{
CleanInternalState();
}
if (!source.IsAbsoluteUri)
{
throw new ArgumentException(SR.Get(SRID.AbsoluteUriOnly), "source");
}
// Resolve Pack://siteoforigin.
if (PackUriHelper.IsPackUri(source))
{
source = BaseUriHelper.ConvertPackUriToAbsoluteExternallyVisibleUri(source);
}
// figure out why BrowserNavConstants.NewWindowsManaged does not work.
object flags = (object)null; // UnsafeNativeMethods.BrowserNavConstants.NewWindowsManaged;
// Fix for inability to navigate to a URI containing invalid UTF-8 sequences
// BindUriHelper.UriToString does use Uri.GetComponents with the UriFormat.SafeUnescaped flag passed in,
// causing invalid UTF-8 sequences to get dropped, resulting in a strictly speaking valid URI but for
// some websites this causes breakage. Therefore we allow ignoring this treatment by means of string-
// based overloads for the public Navigate methods, creating a Uri internally and using AbsoluteUri
// to get back the URI string to feed in to the WebOC in its original form. WinForms has a similar
// set of overloads to enable this scenario.
object sourceString = ignoreEscaping ? source.AbsoluteUri : BindUriHelper.UriToString(source);
try
{
AxIWebBrowser2.Navigate2(ref sourceString, ref flags, ref targetFrameName, ref postData, ref headers);
}
catch (COMException ce)
{
// Clear internal state if Navigation fails.
CleanInternalState();
// "the operation was canceled by the user" - navigation failed
// ignore this error, IE has already alerted the user.
if ((uint)unchecked (ce.ErrorCode) != (uint)unchecked (0x800704c7))
{
throw;
}
}
}
/// <summary>
/// Navigates the WebBrowser control to the next page if available.
/// </summary>
public void GoForward()
{
VerifyAccess();
AxIWebBrowser2.GoForward();
}
/// <summary>
/// Refreshes the current page.
/// </summary>
public void Refresh()
{
VerifyAccess();
AxIWebBrowser2.Refresh();
}
/// <summary>
/// Navigates the WebBrowser control to the previous page if available.
/// </summary>
public void GoBack()
{
VerifyAccess();
AxIWebBrowser2.GoBack();
}
