?Ok, at first GetLastError return an Error object. So you should anything like : Errors.Error err = Errors.GetLastError(); MessageBox.Show(err.Message); For the NodeInfo structure, I think the problem is the same that was for DomainInfo, I'll check marshaling. Then respond you with the correct infos. Arnaud PS : can you also put libvirt-list@redhat.com in copy of your mails, to keep everyone in the loop ? From: 黄亮 Sent: Sunday, October 31, 2010 8:20 AM To: arnaud.champion Subject: Node.GetInfo error Hi, Sorry for disturbing again. But I get error while using Node.GetInfo. Code: NodeInfo aNodeInfo = new NodeInfo(); if (Node.GetInfo(con, aNodeInfo) < 0) { //MessageBox.Show("Node Info Error"); MessageBox.Show(Errors.GetLastError().ToString()); return 0f; } I'm sure con != IntPtr.Zero. I tried to use Errors.GetLastError(), it returns int. But I don't know what to do with it. So, any suggestions ? Thanks Regards 2010-10-31 -------------------------------------------------------------------------------- Lancer