public static object QueryInterface(object obj, Guid iid)
{
if (obj == null)
{
return(null);
}
// get an nsISupports (aka IUnknown) pointer from the objection
IntPtr pUnk = Marshal.GetIUnknownForObject(obj);
if (pUnk == IntPtr.Zero)
{
return(null);
}
// query interface
IntPtr ppv;
Marshal.QueryInterface(pUnk, ref iid, out ppv);
// if QueryInterface didn't work, try using nsIInterfaceRequestor instead
if (ppv == IntPtr.Zero)
{
// QueryInterface the object for nsIInterfaceRequestor
Guid interfaceRequestorIID = typeof(nsIInterfaceRequestor).GUID;
IntPtr pInterfaceRequestor;
Marshal.QueryInterface(pUnk, ref interfaceRequestorIID, out pInterfaceRequestor);
// if we got a pointer to nsIInterfaceRequestor
if (pInterfaceRequestor != IntPtr.Zero)
{
// convert it to a managed interface
QI_nsIInterfaceRequestor req = (QI_nsIInterfaceRequestor)Marshal.GetObjectForIUnknown(pInterfaceRequestor);
// try to get the requested interface
req.GetInterface(ref iid, out ppv);
// clean up
Marshal.ReleaseComObject(req);
Marshal.Release(pInterfaceRequestor);
}
}
object result = (ppv != IntPtr.Zero) ? Marshal.GetObjectForIUnknown(ppv) : null;
Marshal.Release(pUnk);
if (ppv != IntPtr.Zero)
{
Marshal.Release(ppv);
}
return(result);
}
public static object QueryInterface(object obj, Guid iid)
{
AssertCorrectThread();
if (obj == null)
{
return(null);
}
// get an nsISupports (aka IUnknown) pointer from the object
IntPtr pUnk = Marshal.GetIUnknownForObject(obj);
if (pUnk == IntPtr.Zero)
{
return(null);
}
// query interface
IntPtr ppv;
Marshal.QueryInterface(pUnk, ref iid, out ppv);
// if QueryInterface didn't work, try using nsIInterfaceRequestor instead
if (ppv == IntPtr.Zero)
{
// QueryInterface the object for nsIInterfaceRequestor
Guid interfaceRequestorIID = typeof(nsIInterfaceRequestor).GUID;
IntPtr pInterfaceRequestor;
Marshal.QueryInterface(pUnk, ref interfaceRequestorIID, out pInterfaceRequestor);
// if we got a pointer to nsIInterfaceRequestor
if (pInterfaceRequestor != IntPtr.Zero)
{
// convert it to a managed interface
QI_nsIInterfaceRequestor req = (QI_nsIInterfaceRequestor)Xpcom.GetObjectForIUnknown(pInterfaceRequestor);
if (req != null)
{
try
{
req.GetInterface(ref iid, out ppv);
// clean up
Marshal.ReleaseComObject(req);
}
catch (NullReferenceException ex)
{
Debug.WriteLine("NullRefException from native code.\n" + ex.ToString());
}
}
Marshal.Release(pInterfaceRequestor);
}
}
object result = (ppv != IntPtr.Zero) ? Xpcom.GetObjectForIUnknown(ppv) : null;
Marshal.Release(pUnk);
if (ppv != IntPtr.Zero)
{
Marshal.Release(ppv);
}
return(result);
}
