/// <summary>
/// Executes an Active Scripting function defined in the HTML document currently loaded in the WebBrowser control.
/// </summary>
/// <param name="scriptName">The name of the script method to invoke.</param>
/// <param name="args"></param>
/// <returns>The object returned by the Active Scripting call.</returns>
public object InvokeScript(string scriptName, params object[] args)
{
VerifyAccess();
if (string.IsNullOrEmpty(scriptName))
{
throw new ArgumentNullException("scriptName");
}
UnsafeNativeMethods.IDispatchEx scriptObjectEx = null;
UnsafeNativeMethods.IHTMLDocument2 htmlDocument = NativeHTMLDocument;
if (htmlDocument != null)
{
scriptObjectEx = htmlDocument.GetScript() as UnsafeNativeMethods.IDispatchEx;
}
// Protect against the cross domain scripting attacks.
// We rely on the site locking feature in gerneral. But in IE 6 server side redirect is not blocked.
// (In IE 7 it is blocked by turning on the DOCHOSTUIFLAG.ENABLE_REDIRECT_NOTIFICATION flag so that
// the additional BeforeNavigate2 event is fired for server side redirect.)
object retVal = null;
if (scriptObjectEx != null)
{
NativeMethods.DISPPARAMS dp = new NativeMethods.DISPPARAMS();
dp.rgvarg = IntPtr.Zero;
try
{
// If we use reflection to call script code, we need to Assert for the UnmanagedCode permission.
// But it will be a security issue when the WPF app makes a framework object available to the
// hosted script via ObjectForScripting or as paramter of InvokeScript, and calls the framework
// API that demands the UnmanagedCode permission. We do not want the demand to succeed. However,
// The stack walk will igore the native frames and keeps going until it reaches the Assert.
// That is why we switch to invoking the script via IDispatch with SUCS on the methods.
Guid guid = Guid.Empty;
string[] names = new string[] { scriptName };
int[] dispids = new int[] { NativeMethods.DISPID_UNKNOWN };
HRESULT hr = scriptObjectEx.GetIDsOfNames(ref guid, names, 1, Thread.CurrentThread.CurrentCulture.LCID, dispids);
hr.ThrowIfFailed();
if (args != null)
{
// Reverse the arg order so that parms read naturally after IDispatch. (WinForms bug 187662)
Array.Reverse(args);
}
dp.rgvarg = (args == null) ? IntPtr.Zero : UnsafeNativeMethods.ArrayToVARIANTHelper.ArrayToVARIANTVector(args);
dp.cArgs = (uint)((args == null) ? 0 : args.Length);
dp.rgdispidNamedArgs = IntPtr.Zero;
dp.cNamedArgs = 0;
// It's important to use IDispatchEx::InvokeEx here rather than the non-Ex versions for security reasons.
// This version allows us to pass the IServiceProvider for security context.
//
// Calling window.open from within WPF WebBrowser control results in Access Denied script error
// Providing a service provider to InvokeEx only makes sense when nesting occurs (for e.g., when WPF calls
// a script which calls back into WPF which in turn calls the script again) and there is a need to maintain
// the service provider chain. When the execution is from a root occurance, then there is no valid service
// provider that will have all of the information from the stack.
//
// Until recently, IE was ignoring bad service providers -so our passing (IServiceProvider)htmlDocument to InvokeEx
// worked. IE has recently taken a security fix to ensure that it doesn't fall back to the last IOleCommandTarget
// in the chain it found - so now we simply pass null to indicate that this is the root call site.
hr = scriptObjectEx.InvokeEx(
dispids[0],
Thread.CurrentThread.CurrentCulture.LCID,
NativeMethods.DISPATCH_METHOD,
dp,
out retVal,
new NativeMethods.EXCEPINFO(),
null);
hr.ThrowIfFailed();
}
finally
{
if (dp.rgvarg != IntPtr.Zero)
{
UnsafeNativeMethods.ArrayToVARIANTHelper.FreeVARIANTVector(dp.rgvarg, args.Length);
}
}
}
else
{
throw new InvalidOperationException(SR.Get(SRID.CannotInvokeScript));
}
return(retVal);
}
private void HandleTaskbarListError(HRESULT hr)
{
if (hr.Failed)
{
// Even if some of the taskbar methods get this error it doesn't mean that all of them will.
// They aren't all implemented with SendMessageTimeout, and unfortunately the ITaskbarList3 API inconsistently
// exposes that implementation detail.
if (hr == (HRESULT)Win32Error.ERROR_TIMEOUT)
{
// Explorer appears to be busy. Post back to the Window to try again.
if (TraceShell.IsEnabled)
{
TraceShell.Trace(TraceEventType.Error, TraceShell.ExplorerTaskbarTimeout);
TraceShell.Trace(TraceEventType.Warning, TraceShell.ExplorerTaskbarRetrying);
}
// Explorer being hung should be a transient issue. Post back to apply the full TaskbarItemInfo.
_taskbarRetryTimer.Start();
}
else if (hr == (HRESULT)Win32Error.ERROR_INVALID_WINDOW_HANDLE)
{
// We'll get this when Explorer's not running. This means there's no Shell to integrate with.
if (TraceShell.IsEnabled)
{
TraceShell.Trace(TraceEventType.Warning, TraceShell.ExplorerTaskbarNotRunning);
}
// If this is a transient condition then we'll get a WM_TASKBARBUTTONCREATED when Explorer comes
// back and the taskbar button gets created again, at which point we'll rehook.
// In the meantime, just stop trying since there's no reasonable expectation of recovery.
Utilities.SafeRelease(ref _taskbarList);
}
else
{
// That covers the troublesome errors that we know how to handle.
// For anything else we'll ignore the error and count on a subsequent update to correct the state.
if (TraceShell.IsEnabled)
{
TraceShell.Trace(TraceEventType.Error, TraceShell.NativeTaskbarError(hr.ToString()));
}
}
}
}
