c#操作Word的相关问题

public string GetDocumentBookmarkData(string FileName)
        {
            this.OpenWordDoc(FileName, ref wordDoc, ref wordApp);
            object missing = System.Reflection.Missing.Value;

            string str = "";

            System.Collections.IEnumerator enu = wordApp.ActiveDocument.Bookmarks.GetEnumerator();

            while (enu.MoveNext())
            {
                Microsoft.Office.Interop.Word.Bookmark bk = (Microsoft.Office.Interop.Word.Bookmark)enu.Current;
                string str1 = bk.Range.Text;
                str += "{" + bk.Name.ToString() + ":" + bk.Range.Text + "}";
            }
            return str;
        }