private void RegisterCallback(IBindCtx pbc, Uri monikerUri)
{
var callback = new BindStatusCallback(monikerUri, owner);
IBindStatusCallback previous;
IntPtr result = RegisterBindStatusCallback(pbc, callback, out previous, 0);
// The call to RegisterBindStatusCallback will fail if the default calback "_BSCB_Holder_" is registered.
// Remove it and try again. (This trick has been taken from
// <http://www.codeproject.com/KB/atl/vbmhwb.aspx?fid=180355&df=90&mpp=25&noise=3&sort=Position&view=Quick&select=2211230>.)
if (HResults.Equals(result, HResults.E_FAIL) && previous != null)
{
pbc.RevokeObjectParam("_BSCB_Holder_");
callback.PreviousCallback = previous;
result = RegisterBindStatusCallback(pbc, callback, out previous, 0);
}
if (!HResults.Equals(result, HResults.S_OK))
{
throw new InvalidOperationException("Could not register custom bind status callback.");
}
}