把当前选择删除，发生意外，把未删除插回选择。

[c#]代码库

            ElementSet collection = m_doc.Selection.Elements;
            // check user selection
            if (collection.Size < 1)
            {
                MessageBox.Show("Please select an object to delete.", "DeleteObject");
                return;
            }

            bool error = true;
            try
            {
                error = true;

                // delete selection
                IEnumerator e = collection.GetEnumerator();
                bool MoreValue = e.MoveNext();
                while (MoreValue)
                {
                    Element component = e.Current as Element;
                    m_doc.Document.Delete(component);
                    MoreValue = e.MoveNext();
                }

                error = false;
            }
            catch
            {
                // if revit threw an exception, try to catch it
                foreach (Element c in collection)
                {
                    m_doc.Selection.Elements.Insert(c);
                }
                MessageBox.Show("Element(s) can't be deleted.", "DeleteObject");
                return;
            }
            finally
            {
                // if revit threw an exception, display error and return failed
                if (error)
                {
                    MessageBox.Show("Deletion failed.");
                }
            }